Engine misses & backfires

[snip]
>Well first of all you need to find out what cylinder is causing the problem,
>it sounds as if the adaptive numerator needs to be relearned in order for
>the engine controller to determine what cylinder is causing the problem.
>Take vehicle on a test drive and get it up to operating temperature, in
>second gear go about 40 mph and then let go of the accelerator pedal and
>let the vehicle coast down to about 25mph. This will cause the computer to
>learn the crankshaft values and be able to set a fault code for which
>cylinder is misfiring.
>
>Glenn Beasley
>Chrysler Tech

Glen,

The code is P0305 (misfire on #5 cylinder). The garage said this is
the same cylinder that had problems before and "its because the oil is
just sitting down there because the heads are so plugged up the oil
can't be pumped away from the plugs and theres not enough pressure to
power the lifters". "You need to spend about $900 and have these
heads reworked to solve this problem".

Their argument for further proof is that when the engine is left
idling for 20 minutes or so it begins blowing clouds of grey smoke out
the tailpipe but when driven for a mile or so the smoke goes away.
They say thats an oil pressure issue and at high rpms the oil gets
pumped away from the lifters.

The absolute lack of logic in their argument has me seriously doubting
their diagnosis.

Your thoughts?

Phil

On Mon, 06 Jun 2005 17:58:51 -0400, Howdy >
wrote:


>The code is P0305 (misfire on #5 cylinder). The garage said this is
>the same cylinder that had problems before and "its because the oil is
>just sitting down there because the heads are so plugged up the oil
>can't be pumped away from the plugs and theres not enough pressure to
>power the lifters". "You need to spend about $900 and have these
>heads reworked to solve this problem".


It is possible for the drain holes in the heads to get clogged up
causing the oil to collect in the valve cover area. I have only seen
this happen on very sludged up engines or some older GM stuff where
the rubber valve stem seals got brittle, broke and then got stuck in
the drain holes.

In any case you shouldn't need head work to cure an oil draining
problem. Take off the valve cover and check the drains. If they are
clogged clean them out. Very easy to see if this is really the
issue.

Steve B.

"Howdy" > wrote in message
...
> [snip]
> >Well first of all you need to find out what cylinder is causing the
problem,
> >it sounds as if the adaptive numerator needs to be relearned in order for
> >the engine controller to determine what cylinder is causing the problem.
> >Take vehicle on a test drive and get it up to operating temperature, in
> >second gear go about 40 mph and then let go of the accelerator pedal and
> >let the vehicle coast down to about 25mph. This will cause the computer
to
> >learn the crankshaft values and be able to set a fault code for which
> >cylinder is misfiring.
> >
> >Glenn Beasley
> >Chrysler Tech
>
> Glen,
>
> The code is P0305 (misfire on #5 cylinder). The garage said this is
> the same cylinder that had problems before and "its because the oil is
> just sitting down there because the heads are so plugged up the oil
> can't be pumped away from the plugs and theres not enough pressure to
> power the lifters". "You need to spend about $900 and have these
> heads reworked to solve this problem".
>
> Their argument for further proof is that when the engine is left
> idling for 20 minutes or so it begins blowing clouds of grey smoke out
> the tailpipe but when driven for a mile or so the smoke goes away.
> They say thats an oil pressure issue and at high rpms the oil gets
> pumped away from the lifters.
>
> The absolute lack of logic in their argument has me seriously doubting
> their diagnosis.
>
> Your thoughts?
>
> Phil

I have no idea what they are telling you, Only you know if the vehicle has
been maintained properly. sure if you don't change the oil and perform the
routine maintenance the heads could get stopped up and sludged up.
Do you smell strong odors of fuel when this happens? With out looking at the
adaptive fuel memory on the scan tool it would be hard to tell what is
actually going on. Have you taken this vehicle to a dealer with a good
reputation or another independent shop that knows the system? Because what
they are telling you doesn't make any sense to me

[snip]

I my shop read the codes from the PCM and it was a P0305. I replaced
all the plugs, checked the plug wires, rotor and distributor cap and
everything was fine...

Problem is, it still misses and backfires!!!

ARGGGHHHHH!!!!!

wrong plug wires or a failing dist.

Phil wrote:

> [snip]
>
> I my shop read the codes from the PCM and it was a P0305. I replaced
> all the plugs, checked the plug wires, rotor and distributor cap and
> everything was fine...
>
> Problem is, it still misses and backfires!!!
>
> ARGGGHHHHH!!!!!

Three more questions:

Does anyone know where I can "borrow" a code reader? I'm unemployed
and a single dad and I can't afford to take this thing to a shop (and
I'm in north Atlanta).

Second, what is the sensor which is located on the upper intake
manifold just in front of the MAP sensor?

Tim bur suggested that I replace the plugwires, this is the second
set... also suggested I replace the distributor... how do I check out
the distributor to see if its faulty?

"Phil" > wrote in message
...
> Does anyone know where I can "borrow" a code reader? I'm unemployed
> and a single dad and I can't afford to take this thing to a shop (and
> I'm in north Atlanta).

Autozone reads engine codes from OBD-II equipped vehicles for free.

Bob

AutoZone read the PCM codes... came up with two more than my FORMER
garage. The three codes a

P0113 - Input from the Intake Air Tempurature sensor is higher than
expected

P0108 - Input from the MAP sensor is higher than expected for the
current engine operating conditions.

P0305 - miss on cylinder 5.

The autozone guy said it sounded like a short was causing the IAT &
MAP sensors to misbehave.

How can I test the MAP and IAT circuits?

On Wed, 15 Jun 2005 22:26:48 -0400, tim bur > wrote:

>wrong plug wires or a failing dist.
Doesn't make sense... otherwise why would the engine run fine at high
RPMs or when the engine is cold?

See the other posting on the new codes...