1991 MX5 over heating

My car over heated this morning on my way to work, traffic was at
normal speed and the A/C was off, weather is good so outside temp is
not an issue, what should I be checking before taking to the shop.

Abid

wrote:
> My car over heated this morning on my way to work, traffic was at
> normal speed and the A/C was off, weather is good so outside temp is
> not an issue, what should I be checking before taking to the shop.
>
> Abid

My guesses would be the same as for any car: low coolant, blanket of dead
bugs covering the radiator, collapsed hose, bad thermostat, air block in
the system, clogged radiator passages, clogged passages in the engine
block, defective water pump. If the overheating occurred only at low speed
or when stopped I'd add defective fan or fan control. Obviously some of
these are easy to check and some aren't.

--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com

If you're not missing coolant and haven't worked on the cooling system I'd
say the thermostat or valve in radiatorcap is stuck. Try to inspect or clean
them. Cleaning the radiator is an easy thing to do too. If problems stay
think about a blockage somewhere in the system. How old is the waterpump?

Jeroen
Technical Commissioner
Mazda MX-5 Club of the Netherlands

"John McGaw" > schreef in bericht
. ..
| wrote:
| > My car over heated this morning on my way to work, traffic was at
| > normal speed and the A/C was off, weather is good so outside temp is
| > not an issue, what should I be checking before taking to the shop.
| >
| > Abid
|
| My guesses would be the same as for any car: low coolant, blanket of dead
| bugs covering the radiator, collapsed hose, bad thermostat, air block in
| the system, clogged radiator passages, clogged passages in the engine
| block, defective water pump. If the overheating occurred only at low speed
| or when stopped I'd add defective fan or fan control. Obviously some of
| these are easy to check and some aren't.
|
| --
| John McGaw
| [Knoxville, TN, USA]
| http://johnmcgaw.com

On Nov 15, 3:17*am, "jfeelders" <http://mailto.feelders.com> wrote:
> If you're not missing coolant and haven't worked on the cooling system I'd
> say the thermostat or valve in radiatorcap is stuck. Try to inspect or clean
> them. Cleaning the radiator is an easy thing to do too. If problems stay
> think about a blockage somewhere in the system. How old is the waterpump?
>
> Jeroen
> Technical Commissioner
> Mazda MX-5 Club of the Netherlands
>
> "John McGaw" > schreef in th.net...| wrote:
>
> | > My car over heated this morning on my way to work, traffic was at
> | > normal speed and the A/C was off, weather is good so outside temp is
> | > not an issue, what should I be checking before taking to the shop.
> | >
> | > Abid
> |
> | My guesses would be the same as for any car: low coolant, blanket of dead
> | bugs covering the radiator, collapsed hose, bad thermostat, air block in
> | the system, clogged radiator passages, clogged passages in the engine
> | block, defective water pump. If the overheating occurred only at low speed
> | or when stopped I'd add defective fan or fan control. Obviously some of
> | these are easy to check and some aren't.
> |
> | --
> | John McGaw
> | [Knoxville, TN, USA]
> |http://johnmcgaw.com

Well, I couldn't find anything obvious so towed it to the shop, they
found loose alternator (missing bolt) and a bad sensor near the
thermostat, and they replaced the bolt and put the alternator back and
waiting for the sensor from Mazda. I hope that will fix the issue. Abid

On Nov 18, 9:20*am, wrote:
> On Nov 15, 3:17*am, "jfeelders" <http://mailto.feelders.com> wrote:
>
>
>
>
>
> > If you're not missing coolant and haven't worked on the cooling system I'd
> > say the thermostat or valve in radiatorcap is stuck. Try to inspect or clean
> > them. Cleaning the radiator is an easy thing to do too. If problems stay
> > think about a blockage somewhere in the system. How old is the waterpump?
>
> > Jeroen
> > Technical Commissioner
> > Mazda MX-5 Club of the Netherlands
>
> > "John McGaw" > schreef in th.net...| wrote:
>
> > | > My car over heated this morning on my way to work, traffic was at
> > | > normal speed and the A/C was off, weather is good so outside temp is
> > | > not an issue, what should I be checking before taking to the shop.
> > | >
> > | > Abid
> > |
> > | My guesses would be the same as for any car: low coolant, blanket of dead
> > | bugs covering the radiator, collapsed hose, bad thermostat, air block in
> > | the system, clogged radiator passages, clogged passages in the engine
> > | block, defective water pump. If the overheating occurred only at low speed
> > | or when stopped I'd add defective fan or fan control. Obviously some of
> > | these are easy to check and some aren't.
> > |
> > | --
> > | John McGaw
> > | [Knoxville, TN, USA]
> > |http://johnmcgaw.com
>
> Well, I couldn't find anything obvious so towed it to the shop, they
> found loose alternator (missing bolt) and a bad sensor near the
> thermostat, and they replaced the bolt and put the alternator back and
> waiting for the sensor from Mazda. I hope that will fix the issue. Abid- Hide quoted text -
>
> - Show quoted text -

Ok, they replace the sensor and the fan is coming on now so heating
problem is gone, another issue not relatd though, I also asked the to
check the oil leak, which was there before the heating issue, they are
saying there is a leak in the head gas kit and will call me with the
estimate, I need some opinion here how much should it cost and is it
worth getting it fix...

Abid

wrote:

> Ok, they replace the sensor and the fan is coming on now so heating
> problem is gone, another issue not relatd though, I also asked the to
> check the oil leak, which was there before the heating issue, they are
> saying there is a leak in the head gas kit and will call me with the
> estimate, I need some opinion here how much should it cost and is it
> worth getting it fix...
>
> Abid

Not sure on cost, it is going to vary widely in any case.

A leaking head gasket will eventually make the engine inoperable, it is
just a matter of how long it will take.

I would check the coolant for oil mixed in. Also, check the oil to see
if it has any coolant mixed with it.
Does the car let out smoke when then engine is running? If so, does it
only do it at start-up or anytime the car is operating?

Does the car leave any oil on the ground when parked?

How much is it leaking?

This information can all help to tell what the problem is, and how far
along that problem might be.

I would take it in for a second opinion unless this is a shop that you
trust, and I would also call around for price quotes.

It will not be a super-cheap fix, there are quite a few parts to remove
to get to the head.
If the head is warped at all, that will add some additional money as well.

Good luck!

Pat

If the head gasket is truly leaking, the compression and or leakdown should
fail.
I'd be looking to see if the valve cover and related gaskets are actually
the source of the oil leak.
As long as coolant is not getting into the oil, and neither is getting into
the cylinders, you may be able to run for some time before things start
getting out of hand. I suspect a 91 has enough miles and use that the
engine is getting close to replacement (used engine) or overhaul.

"pws" > wrote in message
...
> wrote:
>
>> Ok, they replace the sensor and the fan is coming on now so heating
>> problem is gone, another issue not relatd though, I also asked the to
>> check the oil leak, which was there before the heating issue, they are
>> saying there is a leak in the head gas kit and will call me with the
>> estimate, I need some opinion here how much should it cost and is it
>> worth getting it fix...
>>
>> Abid
>
> Not sure on cost, it is going to vary widely in any case.
>
> A leaking head gasket will eventually make the engine inoperable, it is
> just a matter of how long it will take.
>
> I would check the coolant for oil mixed in. Also, check the oil to see if
> it has any coolant mixed with it.
> Does the car let out smoke when then engine is running? If so, does it
> only do it at start-up or anytime the car is operating?
>
> Does the car leave any oil on the ground when parked?
>
> How much is it leaking?
>
> This information can all help to tell what the problem is, and how far
> along that problem might be.
>
> I would take it in for a second opinion unless this is a shop that you
> trust, and I would also call around for price quotes.
>
> It will not be a super-cheap fix, there are quite a few parts to remove to
> get to the head.
> If the head is warped at all, that will add some additional money as well.
>
> Good luck!
>
> Pat

OH'HO ! Please be careful that type of thinking. If you will look at a
Miata head gasket, you can have a gasket leak without loosing
compression. I had TWO head gasket leaks on my '91 (replaced by Mazda )
and the compression was very good. These showed up on the left front the
first time and the left rear the second thime. I replced it myself and
had no problems after that. Note: clean the surfaces and the proper
torque by the book will fix it. Too many other things can leak on the
upper end of the engine will show up as an oil leak If you aer seeing
oil on the floor or ground, it can't be a sparkplug well "cam cover"
leak. It can be the cam cover gasket at any of the places the cover
changes shape,ie. the base over the cam position hump, the front came
bearing humps I would besure to check all of those places first.

Bruce Bing '03 LS

In article >,
(BRUCE HASKIN) wrote:

> If you aer seeing
> oil on the floor or ground, it can't be a sparkplug well "cam cover"
> leak. It can be the cam cover gasket at any of the places the cover
> changes shape,ie. the base over the cam position hump, the front came
> bearing humps I would besure to check all of those places first.

Another classic leaker is the O-ring that seals the cam angle sensor, at
the rear of the intake cam. Look for drool down the back of the block
(from underneath, on a lift).

--
Lanny Chambers
St. Louis, MO
'94C

On Nov 20, 10:08*pm, Lanny Chambers > wrote:
> In article >,
> (BRUCE HASKIN) wrote:
>
> > If you aer seeing
> > oil on the floor or ground, it can't be a sparkplug well "cam cover"
> > leak. It can be the cam cover gasket at any of the places the cover
> > changes shape,ie. the base over the cam position hump, the front came
> > bearing humps *I would besure to check all of those places first.
>
> Another classic leaker is the O-ring that seals the cam angle sensor, at
> the rear of the intake cam. Look for drool down the back of the block
> (from underneath, on a lift).
>
> --
> Lanny Chambers
> St. Louis, MO
> '94C

Thanks everyone for a all good suggestions/advice. It looks like I
need the head gas kit set (replaced).

Abid