Why does my car ac system keep blowing up?

Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck. It blew
so shortly after starting the truck I have a hard time seeing how the
pressure could be high enough to "blow" but in both cases it popped
the high pressure relief valve and spewed oil and refrigerant out. The
first time it did it I had started the truck, pulled out onto the
street and immediately hit a red light. While at the light I put it
in neutral and gave it enough gas to rev up the engine to 1500 rpm to
run the compressor enough to get more cooling in the 100 degree heat.
After less then a minute of waiting at the light there was a
grunge/screech/smoke/smell and no more cooling. Seemed like the
compressor had locked, oil blew, fan belt screeched over the locked
pulley and the oil burned on the exhaust manifold. Then it unlocked
but no more cooling. Upon tearing it down there was the expected
"black death" look to the oil, it had about 100K miles on the system,
and metal bits at the orifice tube screen. When I took the compressor
apart there were broken bits and obvious new wear marks on the
internals. I got a new compressor, accumulator, orifice tube and
condenser and flushed the evap and all lines. Put it back together
and it ran fine for 4 years.

Then last month I started it up after it sat all day, about a 95
degree day. Started it and just let it idle for no more then 1 to 2
minutes while I arranged my stuff before leaving. Then
grunge/screech/smoke/smell and no more cooling - same thing again but
I hadn't even sped up the engine. Immediately turned it off. Got
out and looked, oil blown out all over the engine again. Turned it
back on and the compressor spun freely, no funny noises, but no
cooling. Unlike the first time, when I tore it down I didn't find
anything much in the system, no little metal chunks, just a little bit
of "blackness" to the oil, a small amount of sludge on the O-tube
screen. The inside of the compressor did not seem to have any broken
parts. From how everything looked I might have been able to fix it
by simply recharging it but I had already ripped the compressor apart.
So I bought all new parts again and redid it last week. Got a
compressor, accumulator, o-tube and condenser from rockauto for $220.
Now it's cooling fine.

Then about 3 days after fixing it I was at the SAME park where it had
blown the second time. Started it up and heard what I thought sounded
like the grudge noise - like the fan belt was just starting to slip
and was fighting it. After having heard this twice before I
immediately turned it off. Thought maybe, just maybe I smelled a tiny
bit of burning oil but there was no smoke like the first two times.
Drove about 3 miles to the store with the AC off and a frown on my
face. Popped the hood and disconnected the compressor. Then started
the engine and turned the ac on. Then plugged the compressor back in
while I watched under the hood. Compressor came on, no funny noises,
and it started to cool!! In fact, it seemed to be working perfectly
normally. So I presume I caught it JUST in time before it blew out
the high pressure blow-off again and spewed oil everywhere.

So at this point my thinking was that maybe I was putting too much oil
in the system and slugging the compressor on start up. So I pulled
the one week old compressor back off and checked the oil level. It
was actually on the low side, certainly not at all overfilled. So put
it back together and it's working just fine.

Sorry for the long post, ...

why is this system blowing up within 1 or 2 minutes after a "cold"
start???? It's always in the 1 or 2 minutes when I would think the
system isn't even working hard yet.

Every time I start the engine (and AC) now I have my finger ready on
the AC on-off button ready to shut it off if I hear the slightest
funny noise.

I put in 80% of the amount of R12 as I'm using 134a. Running it in
the driveway at 2000 rpm I've seen the low side drop to 30 and the
high side go to over 325. I don't see how they could possibly go even
that high, much less to the 400 psi needed to pop the high pressure
valve within 2 minutes after starting with the engine at or near idle
speed.

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?

Ashton Crusher > wrote:
> I put in 80% of the amount of R12 as I'm using 134a. Running it in
>the driveway at 2000 rpm I've seen the low side drop to 30 and the
>high side go to over 325. I don't see how they could possibly go even
>that high, much less to the 400 psi needed to pop the high pressure
>valve within 2 minutes after starting with the engine at or near idle
>speed.
>
>Anyone got any theories? Too much oil? Too much refrigerant? Not
>enough virgins being sacrificed?

Clogged expansion tube. Clogged evaporator.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Thursday, October 15, 2015 at 2:55:33 PM UTC-10, Ashton Crusher wrote:
> Twice now my 92 Explorer has "blown" the compressor. In both cases
> it blew very shortly, within minutes, of starting the truck. It blew
> so shortly after starting the truck I have a hard time seeing how the
> pressure could be high enough to "blow" but in both cases it popped
> the high pressure relief valve and spewed oil and refrigerant out. The
> first time it did it I had started the truck, pulled out onto the
> street and immediately hit a red light. While at the light I put it
> in neutral and gave it enough gas to rev up the engine to 1500 rpm to
> run the compressor enough to get more cooling in the 100 degree heat.
> After less then a minute of waiting at the light there was a
> grunge/screech/smoke/smell and no more cooling. Seemed like the
> compressor had locked, oil blew, fan belt screeched over the locked
> pulley and the oil burned on the exhaust manifold. Then it unlocked
> but no more cooling. Upon tearing it down there was the expected
> "black death" look to the oil, it had about 100K miles on the system,
> and metal bits at the orifice tube screen. When I took the compressor
> apart there were broken bits and obvious new wear marks on the
> internals. I got a new compressor, accumulator, orifice tube and
> condenser and flushed the evap and all lines. Put it back together
> and it ran fine for 4 years.
>
> Then last month I started it up after it sat all day, about a 95
> degree day. Started it and just let it idle for no more then 1 to 2
> minutes while I arranged my stuff before leaving. Then
> grunge/screech/smoke/smell and no more cooling - same thing again but
> I hadn't even sped up the engine. Immediately turned it off. Got
> out and looked, oil blown out all over the engine again. Turned it
> back on and the compressor spun freely, no funny noises, but no
> cooling. Unlike the first time, when I tore it down I didn't find
> anything much in the system, no little metal chunks, just a little bit
> of "blackness" to the oil, a small amount of sludge on the O-tube
> screen. The inside of the compressor did not seem to have any broken
> parts. From how everything looked I might have been able to fix it
> by simply recharging it but I had already ripped the compressor apart.
> So I bought all new parts again and redid it last week. Got a
> compressor, accumulator, o-tube and condenser from rockauto for $220.
> Now it's cooling fine.
>
> Then about 3 days after fixing it I was at the SAME park where it had
> blown the second time. Started it up and heard what I thought sounded
> like the grudge noise - like the fan belt was just starting to slip
> and was fighting it. After having heard this twice before I
> immediately turned it off. Thought maybe, just maybe I smelled a tiny
> bit of burning oil but there was no smoke like the first two times.
> Drove about 3 miles to the store with the AC off and a frown on my
> face. Popped the hood and disconnected the compressor. Then started
> the engine and turned the ac on. Then plugged the compressor back in
> while I watched under the hood. Compressor came on, no funny noises,
> and it started to cool!! In fact, it seemed to be working perfectly
> normally. So I presume I caught it JUST in time before it blew out
> the high pressure blow-off again and spewed oil everywhere.
>
> So at this point my thinking was that maybe I was putting too much oil
> in the system and slugging the compressor on start up. So I pulled
> the one week old compressor back off and checked the oil level. It
> was actually on the low side, certainly not at all overfilled. So put
> it back together and it's working just fine.
>
> Sorry for the long post, ...
>
> why is this system blowing up within 1 or 2 minutes after a "cold"
> start???? It's always in the 1 or 2 minutes when I would think the
> system isn't even working hard yet.
>
> Every time I start the engine (and AC) now I have my finger ready on
> the AC on-off button ready to shut it off if I hear the slightest
> funny noise.
>
> I put in 80% of the amount of R12 as I'm using 134a. Running it in
> the driveway at 2000 rpm I've seen the low side drop to 30 and the
> high side go to over 325. I don't see how they could possibly go even
> that high, much less to the 400 psi needed to pop the high pressure
> valve within 2 minutes after starting with the engine at or near idle
> speed.
>
> Anyone got any theories? Too much oil? Too much refrigerant? Not
> enough virgins being sacrificed?

My guess is that you're getting liquid refrigerant in the low side and into the compressor.

On Thu, 15 Oct 2015 17:55:20 -0700, Ashton Crusher >
wrote:

>Twice now my 92 Explorer has "blown" the compressor. In both cases
>it blew very shortly, within minutes, of starting the truck. It blew
>so shortly after starting the truck I have a hard time seeing how the
>pressure could be high enough to "blow" but in both cases it popped
>the high pressure relief valve and spewed oil and refrigerant out. The
>first time it did it I had started the truck, pulled out onto the
>street and immediately hit a red light. While at the light I put it
>in neutral and gave it enough gas to rev up the engine to 1500 rpm to
>run the compressor enough to get more cooling in the 100 degree heat.
>After less then a minute of waiting at the light there was a
>grunge/screech/smoke/smell and no more cooling. Seemed like the
>compressor had locked, oil blew, fan belt screeched over the locked
>pulley and the oil burned on the exhaust manifold. Then it unlocked
>but no more cooling. Upon tearing it down there was the expected
>"black death" look to the oil, it had about 100K miles on the system,
>and metal bits at the orifice tube screen. When I took the compressor
>apart there were broken bits and obvious new wear marks on the
>internals. I got a new compressor, accumulator, orifice tube and
>condenser and flushed the evap and all lines. Put it back together
>and it ran fine for 4 years.
>
>Then last month I started it up after it sat all day, about a 95
>degree day. Started it and just let it idle for no more then 1 to 2
>minutes while I arranged my stuff before leaving. Then
>grunge/screech/smoke/smell and no more cooling - same thing again but
>I hadn't even sped up the engine. Immediately turned it off. Got
>out and looked, oil blown out all over the engine again. Turned it
>back on and the compressor spun freely, no funny noises, but no
>cooling. Unlike the first time, when I tore it down I didn't find
>anything much in the system, no little metal chunks, just a little bit
>of "blackness" to the oil, a small amount of sludge on the O-tube
>screen. The inside of the compressor did not seem to have any broken
>parts. From how everything looked I might have been able to fix it
>by simply recharging it but I had already ripped the compressor apart.
>So I bought all new parts again and redid it last week. Got a
>compressor, accumulator, o-tube and condenser from rockauto for $220.
>Now it's cooling fine.
>
>Then about 3 days after fixing it I was at the SAME park where it had
>blown the second time. Started it up and heard what I thought sounded
>like the grudge noise - like the fan belt was just starting to slip
>and was fighting it. After having heard this twice before I
>immediately turned it off. Thought maybe, just maybe I smelled a tiny
>bit of burning oil but there was no smoke like the first two times.
>Drove about 3 miles to the store with the AC off and a frown on my
>face. Popped the hood and disconnected the compressor. Then started
>the engine and turned the ac on. Then plugged the compressor back in
>while I watched under the hood. Compressor came on, no funny noises,
>and it started to cool!! In fact, it seemed to be working perfectly
>normally. So I presume I caught it JUST in time before it blew out
>the high pressure blow-off again and spewed oil everywhere.
>
>So at this point my thinking was that maybe I was putting too much oil
>in the system and slugging the compressor on start up. So I pulled
>the one week old compressor back off and checked the oil level. It
>was actually on the low side, certainly not at all overfilled. So put
>it back together and it's working just fine.
>
>Sorry for the long post, ...
>
>why is this system blowing up within 1 or 2 minutes after a "cold"
>start???? It's always in the 1 or 2 minutes when I would think the
>system isn't even working hard yet.
>
> Every time I start the engine (and AC) now I have my finger ready on
>the AC on-off button ready to shut it off if I hear the slightest
>funny noise.
>
> I put in 80% of the amount of R12 as I'm using 134a. Running it in
>the driveway at 2000 rpm I've seen the low side drop to 30 and the
>high side go to over 325. I don't see how they could possibly go even
>that high, much less to the 400 psi needed to pop the high pressure
>valve within 2 minutes after starting with the engine at or near idle
>speed.
>
>Anyone got any theories? Too much oil? Too much refrigerant? Not
>enough virgins being sacrificed?

I know nothing about this particular vehicle, but if it uses electric
coolant fans, the it's possible that the high speed fan and/or relay
are either not working, or are intermittent. If intermittent, check
the high current wiring to the fan - those connectors get hot, and
start to fail. The relay, too.

If the fan is belt driven, you might have a bad fan clutch, but I'd
expect the engine to run hot at times.

Check for obstructions in the air flow through the condenser.

On 15 Oct 2015 20:59:46 -0400, (Scott Dorsey) wrote:

>Ashton Crusher > wrote:
>> I put in 80% of the amount of R12 as I'm using 134a. Running it in
>>the driveway at 2000 rpm I've seen the low side drop to 30 and the
>>high side go to over 325. I don't see how they could possibly go even
>>that high, much less to the 400 psi needed to pop the high pressure
>>valve within 2 minutes after starting with the engine at or near idle
>>speed.
>>
>>Anyone got any theories? Too much oil? Too much refrigerant? Not
>>enough virgins being sacrificed?
>
>Clogged expansion tube. Clogged evaporator.
>--scott

Evap was not clogged either time. Doesn't have an expansion tube,
just an orifice tube. I guess that could clog but there is a filter
screen before anything gets to it. Why would it do so immediately
after starting and while idling yet never do so while running down the
highway for hours on end?

On Thu, 15 Oct 2015 18:23:39 -0700 (PDT), dsi1 >
wrote:

>On Thursday, October 15, 2015 at 2:55:33 PM UTC-10, Ashton Crusher wrote:
>> Twice now my 92 Explorer has "blown" the compressor. In both cases
>> it blew very shortly, within minutes, of starting the truck. It blew
>> so shortly after starting the truck I have a hard time seeing how the
>> pressure could be high enough to "blow" but in both cases it popped
>> the high pressure relief valve and spewed oil and refrigerant out. The
>> first time it did it I had started the truck, pulled out onto the
>> street and immediately hit a red light. While at the light I put it
>> in neutral and gave it enough gas to rev up the engine to 1500 rpm to
>> run the compressor enough to get more cooling in the 100 degree heat.
>> After less then a minute of waiting at the light there was a
>> grunge/screech/smoke/smell and no more cooling. Seemed like the
>> compressor had locked, oil blew, fan belt screeched over the locked
>> pulley and the oil burned on the exhaust manifold. Then it unlocked
>> but no more cooling. Upon tearing it down there was the expected
>> "black death" look to the oil, it had about 100K miles on the system,
>> and metal bits at the orifice tube screen. When I took the compressor
>> apart there were broken bits and obvious new wear marks on the
>> internals. I got a new compressor, accumulator, orifice tube and
>> condenser and flushed the evap and all lines. Put it back together
>> and it ran fine for 4 years.
>>
>> Then last month I started it up after it sat all day, about a 95
>> degree day. Started it and just let it idle for no more then 1 to 2
>> minutes while I arranged my stuff before leaving. Then
>> grunge/screech/smoke/smell and no more cooling - same thing again but
>> I hadn't even sped up the engine. Immediately turned it off. Got
>> out and looked, oil blown out all over the engine again. Turned it
>> back on and the compressor spun freely, no funny noises, but no
>> cooling. Unlike the first time, when I tore it down I didn't find
>> anything much in the system, no little metal chunks, just a little bit
>> of "blackness" to the oil, a small amount of sludge on the O-tube
>> screen. The inside of the compressor did not seem to have any broken
>> parts. From how everything looked I might have been able to fix it
>> by simply recharging it but I had already ripped the compressor apart.
>> So I bought all new parts again and redid it last week. Got a
>> compressor, accumulator, o-tube and condenser from rockauto for $220.
>> Now it's cooling fine.
>>
>> Then about 3 days after fixing it I was at the SAME park where it had
>> blown the second time. Started it up and heard what I thought sounded
>> like the grudge noise - like the fan belt was just starting to slip
>> and was fighting it. After having heard this twice before I
>> immediately turned it off. Thought maybe, just maybe I smelled a tiny
>> bit of burning oil but there was no smoke like the first two times.
>> Drove about 3 miles to the store with the AC off and a frown on my
>> face. Popped the hood and disconnected the compressor. Then started
>> the engine and turned the ac on. Then plugged the compressor back in
>> while I watched under the hood. Compressor came on, no funny noises,
>> and it started to cool!! In fact, it seemed to be working perfectly
>> normally. So I presume I caught it JUST in time before it blew out
>> the high pressure blow-off again and spewed oil everywhere.
>>
>> So at this point my thinking was that maybe I was putting too much oil
>> in the system and slugging the compressor on start up. So I pulled
>> the one week old compressor back off and checked the oil level. It
>> was actually on the low side, certainly not at all overfilled. So put
>> it back together and it's working just fine.
>>
>> Sorry for the long post, ...
>>
>> why is this system blowing up within 1 or 2 minutes after a "cold"
>> start???? It's always in the 1 or 2 minutes when I would think the
>> system isn't even working hard yet.
>>
>> Every time I start the engine (and AC) now I have my finger ready on
>> the AC on-off button ready to shut it off if I hear the slightest
>> funny noise.
>>
>> I put in 80% of the amount of R12 as I'm using 134a. Running it in
>> the driveway at 2000 rpm I've seen the low side drop to 30 and the
>> high side go to over 325. I don't see how they could possibly go even
>> that high, much less to the 400 psi needed to pop the high pressure
>> valve within 2 minutes after starting with the engine at or near idle
>> speed.
>>
>> Anyone got any theories? Too much oil? Too much refrigerant? Not
>> enough virgins being sacrificed?
>
>My guess is that you're getting liquid refrigerant in the low side and into the compressor.

You mean it's simply got too much refrigerant in it or do you mean
there is something making the normal amount pool where it's not
supposed to and then hitting the compressor? Can you think of any
reason there would be a bunch of liquid refrigerant in the system when
it's only been running for barely two minutes? Isn't all the
refrigerant in a vapor state until the compressor starts running?
That's what makes me scratch my head... it's failed twice, and nearly
a third time, so shortly after it's started to run. It hardly seems
like it has enough time to build up a head of pressure short of
something literally plugging the system or slugging the compressor.

On Thu, 15 Oct 2015 18:34:03 -0700, Bill Vanek >
wrote:

>On Thu, 15 Oct 2015 17:55:20 -0700, Ashton Crusher >
>wrote:
>
>>Twice now my 92 Explorer has "blown" the compressor. In both cases
>>it blew very shortly, within minutes, of starting the truck. It blew
>>so shortly after starting the truck I have a hard time seeing how the
>>pressure could be high enough to "blow" but in both cases it popped
>>the high pressure relief valve and spewed oil and refrigerant out. The
>>first time it did it I had started the truck, pulled out onto the
>>street and immediately hit a red light. While at the light I put it
>>in neutral and gave it enough gas to rev up the engine to 1500 rpm to
>>run the compressor enough to get more cooling in the 100 degree heat.
>>After less then a minute of waiting at the light there was a
>>grunge/screech/smoke/smell and no more cooling. Seemed like the
>>compressor had locked, oil blew, fan belt screeched over the locked
>>pulley and the oil burned on the exhaust manifold. Then it unlocked
>>but no more cooling. Upon tearing it down there was the expected
>>"black death" look to the oil, it had about 100K miles on the system,
>>and metal bits at the orifice tube screen. When I took the compressor
>>apart there were broken bits and obvious new wear marks on the
>>internals. I got a new compressor, accumulator, orifice tube and
>>condenser and flushed the evap and all lines. Put it back together
>>and it ran fine for 4 years.
>>
>>Then last month I started it up after it sat all day, about a 95
>>degree day. Started it and just let it idle for no more then 1 to 2
>>minutes while I arranged my stuff before leaving. Then
>>grunge/screech/smoke/smell and no more cooling - same thing again but
>>I hadn't even sped up the engine. Immediately turned it off. Got
>>out and looked, oil blown out all over the engine again. Turned it
>>back on and the compressor spun freely, no funny noises, but no
>>cooling. Unlike the first time, when I tore it down I didn't find
>>anything much in the system, no little metal chunks, just a little bit
>>of "blackness" to the oil, a small amount of sludge on the O-tube
>>screen. The inside of the compressor did not seem to have any broken
>>parts. From how everything looked I might have been able to fix it
>>by simply recharging it but I had already ripped the compressor apart.
>>So I bought all new parts again and redid it last week. Got a
>>compressor, accumulator, o-tube and condenser from rockauto for $220.
>>Now it's cooling fine.
>>
>>Then about 3 days after fixing it I was at the SAME park where it had
>>blown the second time. Started it up and heard what I thought sounded
>>like the grudge noise - like the fan belt was just starting to slip
>>and was fighting it. After having heard this twice before I
>>immediately turned it off. Thought maybe, just maybe I smelled a tiny
>>bit of burning oil but there was no smoke like the first two times.
>>Drove about 3 miles to the store with the AC off and a frown on my
>>face. Popped the hood and disconnected the compressor. Then started
>>the engine and turned the ac on. Then plugged the compressor back in
>>while I watched under the hood. Compressor came on, no funny noises,
>>and it started to cool!! In fact, it seemed to be working perfectly
>>normally. So I presume I caught it JUST in time before it blew out
>>the high pressure blow-off again and spewed oil everywhere.
>>
>>So at this point my thinking was that maybe I was putting too much oil
>>in the system and slugging the compressor on start up. So I pulled
>>the one week old compressor back off and checked the oil level. It
>>was actually on the low side, certainly not at all overfilled. So put
>>it back together and it's working just fine.
>>
>>Sorry for the long post, ...
>>
>>why is this system blowing up within 1 or 2 minutes after a "cold"
>>start???? It's always in the 1 or 2 minutes when I would think the
>>system isn't even working hard yet.
>>
>> Every time I start the engine (and AC) now I have my finger ready on
>>the AC on-off button ready to shut it off if I hear the slightest
>>funny noise.
>>
>> I put in 80% of the amount of R12 as I'm using 134a. Running it in
>>the driveway at 2000 rpm I've seen the low side drop to 30 and the
>>high side go to over 325. I don't see how they could possibly go even
>>that high, much less to the 400 psi needed to pop the high pressure
>>valve within 2 minutes after starting with the engine at or near idle
>>speed.
>>
>>Anyone got any theories? Too much oil? Too much refrigerant? Not
>>enough virgins being sacrificed?
>
>I know nothing about this particular vehicle, but if it uses electric
>coolant fans, the it's possible that the high speed fan and/or relay
>are either not working, or are intermittent. If intermittent, check
>the high current wiring to the fan - those connectors get hot, and
>start to fail. The relay, too.
>
>If the fan is belt driven, you might have a bad fan clutch, but I'd
>expect the engine to run hot at times.
>
>Check for obstructions in the air flow through the condenser.

Those are good ideas. It doesn't have electric fans though and
doesn't run hot. The condenser was very clean both times it failed.

Ashton Crusher wrote:
> Twice now my 92 Explorer has "blown" the compressor. In both cases
> it blew very shortly, within minutes, of starting the truck. It blew
> so shortly after starting the truck I have a hard time seeing how the
> pressure could be high enough to "blow" but in both cases it popped
> the high pressure relief valve and spewed oil and refrigerant out.
....

Black gunk may be contamination... or due to compressor failure.
Will assume the oil was correct type.
First occasion could be due to not enough cleaning and purging.
2nd and almost 3rd, not likely.
Were the oem hoses changed out for 134a hoses?

On Thu, 15 Oct 2015 19:00:27 -0700, Ashton Crusher >
wrote:

>On Thu, 15 Oct 2015 18:34:03 -0700, Bill Vanek >
>wrote:
>
>>On Thu, 15 Oct 2015 17:55:20 -0700, Ashton Crusher >
>>wrote:
>>
>>>Twice now my 92 Explorer has "blown" the compressor. In both cases
>>>it blew very shortly, within minutes, of starting the truck. It blew
>>>so shortly after starting the truck I have a hard time seeing how the
>>>pressure could be high enough to "blow" but in both cases it popped
>>>the high pressure relief valve and spewed oil and refrigerant out. The
>>>first time it did it I had started the truck, pulled out onto the
>>>street and immediately hit a red light. While at the light I put it
>>>in neutral and gave it enough gas to rev up the engine to 1500 rpm to
>>>run the compressor enough to get more cooling in the 100 degree heat.
>>>After less then a minute of waiting at the light there was a
>>>grunge/screech/smoke/smell and no more cooling. Seemed like the
>>>compressor had locked, oil blew, fan belt screeched over the locked
>>>pulley and the oil burned on the exhaust manifold. Then it unlocked
>>>but no more cooling. Upon tearing it down there was the expected
>>>"black death" look to the oil, it had about 100K miles on the system,
>>>and metal bits at the orifice tube screen. When I took the compressor
>>>apart there were broken bits and obvious new wear marks on the
>>>internals. I got a new compressor, accumulator, orifice tube and
>>>condenser and flushed the evap and all lines. Put it back together
>>>and it ran fine for 4 years.
>>>
>>>Then last month I started it up after it sat all day, about a 95
>>>degree day. Started it and just let it idle for no more then 1 to 2
>>>minutes while I arranged my stuff before leaving. Then
>>>grunge/screech/smoke/smell and no more cooling - same thing again but
>>>I hadn't even sped up the engine. Immediately turned it off. Got
>>>out and looked, oil blown out all over the engine again. Turned it
>>>back on and the compressor spun freely, no funny noises, but no
>>>cooling. Unlike the first time, when I tore it down I didn't find
>>>anything much in the system, no little metal chunks, just a little bit
>>>of "blackness" to the oil, a small amount of sludge on the O-tube
>>>screen. The inside of the compressor did not seem to have any broken
>>>parts. From how everything looked I might have been able to fix it
>>>by simply recharging it but I had already ripped the compressor apart.
>>>So I bought all new parts again and redid it last week. Got a
>>>compressor, accumulator, o-tube and condenser from rockauto for $220.
>>>Now it's cooling fine.
>>>
>>>Then about 3 days after fixing it I was at the SAME park where it had
>>>blown the second time. Started it up and heard what I thought sounded
>>>like the grudge noise - like the fan belt was just starting to slip
>>>and was fighting it. After having heard this twice before I
>>>immediately turned it off. Thought maybe, just maybe I smelled a tiny
>>>bit of burning oil but there was no smoke like the first two times.
>>>Drove about 3 miles to the store with the AC off and a frown on my
>>>face. Popped the hood and disconnected the compressor. Then started
>>>the engine and turned the ac on. Then plugged the compressor back in
>>>while I watched under the hood. Compressor came on, no funny noises,
>>>and it started to cool!! In fact, it seemed to be working perfectly
>>>normally. So I presume I caught it JUST in time before it blew out
>>>the high pressure blow-off again and spewed oil everywhere.
>>>
>>>So at this point my thinking was that maybe I was putting too much oil
>>>in the system and slugging the compressor on start up. So I pulled
>>>the one week old compressor back off and checked the oil level. It
>>>was actually on the low side, certainly not at all overfilled. So put
>>>it back together and it's working just fine.
>>>
>>>Sorry for the long post, ...
>>>
>>>why is this system blowing up within 1 or 2 minutes after a "cold"
>>>start???? It's always in the 1 or 2 minutes when I would think the
>>>system isn't even working hard yet.
>>>
>>> Every time I start the engine (and AC) now I have my finger ready on
>>>the AC on-off button ready to shut it off if I hear the slightest
>>>funny noise.
>>>
>>> I put in 80% of the amount of R12 as I'm using 134a. Running it in
>>>the driveway at 2000 rpm I've seen the low side drop to 30 and the
>>>high side go to over 325. I don't see how they could possibly go even
>>>that high, much less to the 400 psi needed to pop the high pressure
>>>valve within 2 minutes after starting with the engine at or near idle
>>>speed.
>>>
>>>Anyone got any theories? Too much oil? Too much refrigerant? Not
>>>enough virgins being sacrificed?
>>
>>I know nothing about this particular vehicle, but if it uses electric
>>coolant fans, the it's possible that the high speed fan and/or relay
>>are either not working, or are intermittent. If intermittent, check
>>the high current wiring to the fan - those connectors get hot, and
>>start to fail. The relay, too.
>>
>>If the fan is belt driven, you might have a bad fan clutch, but I'd
>>expect the engine to run hot at times.
>>
>>Check for obstructions in the air flow through the condenser.
>
>Those are good ideas. It doesn't have electric fans though and
>doesn't run hot. The condenser was very clean both times it failed.

Is it failing to cycle at times? Also, have you put gauges on it?

On Thu, 15 Oct 2015 19:00:27 -0700, Ashton Crusher >
wrote:

>On Thu, 15 Oct 2015 18:34:03 -0700, Bill Vanek >
>wrote:
>
>>On Thu, 15 Oct 2015 17:55:20 -0700, Ashton Crusher >
>>wrote:
>>
>>>Twice now my 92 Explorer has "blown" the compressor. In both cases
>>>it blew very shortly, within minutes, of starting the truck. It blew
>>>so shortly after starting the truck I have a hard time seeing how the
>>>pressure could be high enough to "blow" but in both cases it popped
>>>the high pressure relief valve and spewed oil and refrigerant out. The
>>>first time it did it I had started the truck, pulled out onto the
>>>street and immediately hit a red light. While at the light I put it
>>>in neutral and gave it enough gas to rev up the engine to 1500 rpm to
>>>run the compressor enough to get more cooling in the 100 degree heat.
>>>After less then a minute of waiting at the light there was a
>>>grunge/screech/smoke/smell and no more cooling. Seemed like the
>>>compressor had locked, oil blew, fan belt screeched over the locked
>>>pulley and the oil burned on the exhaust manifold. Then it unlocked
>>>but no more cooling. Upon tearing it down there was the expected
>>>"black death" look to the oil, it had about 100K miles on the system,
>>>and metal bits at the orifice tube screen. When I took the compressor
>>>apart there were broken bits and obvious new wear marks on the
>>>internals. I got a new compressor, accumulator, orifice tube and
>>>condenser and flushed the evap and all lines. Put it back together
>>>and it ran fine for 4 years.
>>>
>>>Then last month I started it up after it sat all day, about a 95
>>>degree day. Started it and just let it idle for no more then 1 to 2
>>>minutes while I arranged my stuff before leaving. Then
>>>grunge/screech/smoke/smell and no more cooling - same thing again but
>>>I hadn't even sped up the engine. Immediately turned it off. Got
>>>out and looked, oil blown out all over the engine again. Turned it
>>>back on and the compressor spun freely, no funny noises, but no
>>>cooling. Unlike the first time, when I tore it down I didn't find
>>>anything much in the system, no little metal chunks, just a little bit
>>>of "blackness" to the oil, a small amount of sludge on the O-tube
>>>screen. The inside of the compressor did not seem to have any broken
>>>parts. From how everything looked I might have been able to fix it
>>>by simply recharging it but I had already ripped the compressor apart.
>>>So I bought all new parts again and redid it last week. Got a
>>>compressor, accumulator, o-tube and condenser from rockauto for $220.
>>>Now it's cooling fine.
>>>
>>>Then about 3 days after fixing it I was at the SAME park where it had
>>>blown the second time. Started it up and heard what I thought sounded
>>>like the grudge noise - like the fan belt was just starting to slip
>>>and was fighting it. After having heard this twice before I
>>>immediately turned it off. Thought maybe, just maybe I smelled a tiny
>>>bit of burning oil but there was no smoke like the first two times.
>>>Drove about 3 miles to the store with the AC off and a frown on my
>>>face. Popped the hood and disconnected the compressor. Then started
>>>the engine and turned the ac on. Then plugged the compressor back in
>>>while I watched under the hood. Compressor came on, no funny noises,
>>>and it started to cool!! In fact, it seemed to be working perfectly
>>>normally. So I presume I caught it JUST in time before it blew out
>>>the high pressure blow-off again and spewed oil everywhere.
>>>
>>>So at this point my thinking was that maybe I was putting too much oil
>>>in the system and slugging the compressor on start up. So I pulled
>>>the one week old compressor back off and checked the oil level. It
>>>was actually on the low side, certainly not at all overfilled. So put
>>>it back together and it's working just fine.
>>>
>>>Sorry for the long post, ...
>>>
>>>why is this system blowing up within 1 or 2 minutes after a "cold"
>>>start???? It's always in the 1 or 2 minutes when I would think the
>>>system isn't even working hard yet.
>>>
>>> Every time I start the engine (and AC) now I have my finger ready on
>>>the AC on-off button ready to shut it off if I hear the slightest
>>>funny noise.
>>>
>>> I put in 80% of the amount of R12 as I'm using 134a. Running it in
>>>the driveway at 2000 rpm I've seen the low side drop to 30 and the
>>>high side go to over 325. I don't see how they could possibly go even
>>>that high, much less to the 400 psi needed to pop the high pressure
>>>valve within 2 minutes after starting with the engine at or near idle
>>>speed.
>>>
>>>Anyone got any theories? Too much oil? Too much refrigerant? Not
>>>enough virgins being sacrificed?
>>
>>I know nothing about this particular vehicle, but if it uses electric
>>coolant fans, the it's possible that the high speed fan and/or relay
>>are either not working, or are intermittent. If intermittent, check
>>the high current wiring to the fan - those connectors get hot, and
>>start to fail. The relay, too.
>>
>>If the fan is belt driven, you might have a bad fan clutch, but I'd
>>expect the engine to run hot at times.
>>
>>Check for obstructions in the air flow through the condenser.
>
>Those are good ideas. It doesn't have electric fans though and
>doesn't run hot. The condenser was very clean both times it failed.

BTW, did you evacuate the system after you opened it?