[Mk2] [NA] Car running very low temperature.

[BALDYMONSTER]

Obviously the drop in weather temp is going to effect this especially in Jockland where it's currently about 4-7 degrees.

But my car seems to be constantly running at half its normal operating temp.

Cut the slays out the side vents when I got the car resprayed but I wouldn't have thought that would have made anywhere near that much difference.

Anyone else have this issue?

[pistol pete]

You need a new thermostat

guessing you mean temp gauge only gets to about 1/4

[BALDYMONSTER]

I had that suspicion.

Where's the thermostat housing on them?

Rev 2 uk model.

[Darkzy433]

I've got this same problem, the 10mm nuts on the thermo housing are a pain to undo.. I gave up trying to do it as I couldn't get a decent hold on the bottom nut with any sort of socket and there is no way you will get a spanner in there.

The housing is on the drivers side of the engine bay, near the dipstick.

If you attempt make sure you use a good quality 6 sided socket as thse are prone to rounding.

[BALDYMONSTER]

This will be a job for Jaffa me thinks.

[raptor95GTS]

This will be a job for Jaffa me thinks.

haha, he's gonna love that job

[BALDYMONSTER]

The guy knows his way round an MR2 like you wouldn't believe!

[tiff_lee]

You need a new thermostat

That or it needs one fitting!

The old classic mod of making your car run 'cooler'.

[BALDYMONSTER]

Needle is now dropping down and bouncing back as it suits itself.

Going to change the dash tonight.

[2mad]

My car always sat up to temp at half temp .. never had a problem

[BALDYMONSTER]

Ok changed entire dash over, and now needle is stable but still seems too cool to me.

It's 2 degrees up here, took car for 20 minute run, never above 40mph, did have the heater on half blast at hottest setting mind, but it's never run this cool, before.

I'll post up pic of needle position.

New thermostat on it's way to me regardless.

[BALDYMONSTER]

[stuMR2lee]

I had a similar issue with my current car. Took a long time for the needle to rise and rarely went higher than your picture. It turned out to be the temperature gauge sender. Easy cheap fix and now the needle gets up to just under half way within about 5 minutes of driving and stays rock solid.

If the radiator gets hot enough after a run that the rad fan comes on and the heaters get hot then suspect the sensor.

Obviously if it's erratic it could be a stuck open thermostat or possibly air in the system (had that on my first NA - turned out to be a pin hole leak on the rad). Are you losing any coolant?

[BALDYMONSTER]

Don't appear to be losing coolant but recently had to top up with it.


Where is the temp gauge sender?

[stuMR2lee]

I think on a Rev1/2 it's the single spade connector one on the coolant tree. Rev3 plus are different I believe.

Take the wire off the sensor and earth to the engine, if the gauge goes to full then the sensor is at fault, if it doesn't move its either a wiring fault or gauge fault. (info borrowed from a forum post by jimi on Mr2oc.uk).

http://i30.tinypic.com/2ptp7c4.jpg

[BALDYMONSTER]

That's the new needle being totally erratic now so must be sender switch.

[BALDYMONSTER]

New sender switch bought from eBay for a little over £6 and free postage.

Toyota wanted nearly £40!

[bobhatton]

New sender switch bought from eBay for a little over £6 and free postage.

Toyota wanted nearly £40!

One made in Japan and the other in China

[raptor95GTS]

have you checked the radiator pipes? If both pipes are hot (one should be cooler than the other but still damned hot) then the thermostat is working, if they're cold then the thermostat isn't doing it's job. Change and recheck operation

[tiff_lee]

Have you inspected the connection on the temperature sender at all? The sensor is just a thermistor, I can't imagine how the sensor itself would be causing wild swings on the gauge.