Help! Engine Temp issues....

Help! Engine Temp issues....

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MrFlibbles

Original Poster:

7,692 posts

284 months

Sunday 28th November 2004
quotequote all
Picked the mrt up yesterday, have been bombing about in it ever since. Once warm the engine temp needle always sits at half way. I have been giving it sporadic bursts of full accel but no major workout.

So this afternoon, i took it for a proper blast - plenty of empty dual carriageway, interspersed with roundabouts, twas a proper fun drive. Probably about 25 miles of maximum attack. Engine water temp gauge still at half way....

Then, towards the end of the jaunt, traffic forced me to slow right down. The needle started climbing. Then we had to stop for just over a min. The needle climb and climbed, and stopped just short of the red.

Now Im seriously worried. So we get moving and keeping it below 2.5 - 3k, at about 60mph, the needle starts coming down, until it is back down at 'normal'. But then, its as if the needle has a mind of its own, up to 3/4 then down to 1/2, then up to 3/4 back to 1/2, all the way home. The movement was percepitible.

So when I got home, I let it idle, and it settled at 1/2.

Have I ed something up? Have I bought a lemon? Do TADTS? Whats going on? Help!

Im panicing!

MrFlibbles

Original Poster:

7,692 posts

284 months

Sunday 28th November 2004
quotequote all
Could it be an air in the cooling system perhaps? Or a faulty thermostat?

GreenV8S

30,220 posts

285 months

Sunday 28th November 2004
quotequote all
Do the fans work properly?

DanBoy

4,899 posts

244 months

Sunday 28th November 2004
quotequote all
Gazboy said:

Make sure the front radiator isn't clogged with leaves btw.


My temp gauge normally sits around the half way mark.

Strange thing is that it sometimes drops when I start really giving it some stick then rises back up to half way when sat idling in traffic. I guess the cooling effect of the air more than counteracts the heat being generated at high speed, but then I don't suffer from the heat problems associated with forced induction (although I wish I did to be honest)!

tuttle

3,427 posts

238 months

Sunday 28th November 2004
quotequote all
Check thermostat & cooling fans/switch would be my 1st point to check too.If the temp is dropping when you move off-then it should'nt be all bad .Might be an idea to have a look in the rad too,see if its just plain old water or water coolant mix.

MrFlibbles

Original Poster:

7,692 posts

284 months

Sunday 28th November 2004
quotequote all
The fans are kicking in fine. Front intake not clogged either. The coolant is the Toyota Red stuff.

I had it out for a little run tonight, and it was fine.

Hmmmmm....

A quick google suggested air in the system. Sounds plausible to me?

Btw thermostat replaced a few months ago...

tuttle

3,427 posts

238 months

Monday 29th November 2004
quotequote all
Would be surprised if you had air bubbles in a modern cooling system(unless tiny split in hosing perhaps)
Some other reasons why engines can run hot:
(Not trying to scare you or anything)
Fuel mixture too lean.
Fuel RON not high enough(bad fuel )
High detonation or knock level.
Brakes binding.
Cooling surfaces not getting air flow.

Maybe it just runs a bit hot.

Any of you MR2 gurus,you aware of any ideosyncrosies with MR2 cooling?

Mr E

21,635 posts

260 months

Monday 29th November 2004
quotequote all
MR2s do have cooling problems. Something to do with the engine being in the wrong place.

I get a heat haze over the bonnet such that I struggle to see when the car is stationary following a maximum attack run. The Temp gauge never moves.

Any idea what level of boost you're running?

Don't wish to scare you, but my mate had the head off his 1991 MR2 Turbo recently, and discovered all the cooling lines were corroded away to nothing.

Norris Designs rebuilt the head, and he now has wide angle ported valves as well. Should be good.

MrFlibbles

Original Poster:

7,692 posts

284 months

Monday 29th November 2004
quotequote all
Running standard boost AFAIK.

Had it out and about today, and it seems fine now