My car overheated (but all fine now)
My car overheated (but all fine now)
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Harry Flashman

Original Poster:

21,342 posts

266 months

Tuesday 29th March 2005
quotequote all
She started blowing steam out all over the place, and so before the engine could get any hotter and warp the heads, I pulled over, and left her overnight to cool (luckily close to home).

Shorted the fan to provide permanent cooling, and got the car home - temperature high, but not in the red. Flushed everything. Tested thermostat - and found it was not opening.

Changed thermostat, coolant etc - and the car holds steady at 90 degrees. No more steam, no more people pointing and laughing etc. Hurrah! Victory.

They question then, I guess. If the thermostat wasn't opening, how did my shorting the fan to run permanently keep the temperature within bounds on my way home? If I had a defective stat, surely the hot coolant would never make it to the radiator to be cooled down by the airflow?

Should I be looking for something else too (checked the fan - it is happily coming on when the engine gets a bit above 90 degrees, so it's not the thermostatic switch).

Yours confusedly,

Harry.

DarkMatter

1,498 posts

255 months

Tuesday 29th March 2005
quotequote all
Could it be that conduction was having a beneficial effect? Even though the thermostsat was not open cooling the water in the radiator would draw hotter water from the engine via the bottom hose.

Also, the cooling fans could have been drawing cooler air across the engine.

Well, that's my guess anyway.

GreenV8S

30,999 posts

308 months

Tuesday 29th March 2005
quotequote all
Stats often fail partially open, so they overcool the engine at higher speed/lower power, and undercool it at lower speeds/higher power. So you do get some cooling but sometimes too much and sometimes too little. If you were starting from cold fairly close to home, it may have been undercooling but not enough to overheat before you reached home.

Pies

13,116 posts

280 months

Tuesday 29th March 2005
quotequote all
Did you have the heater on?

DarkMatter

1,498 posts

255 months

Tuesday 29th March 2005
quotequote all
Pies said:
Did you have the heater on?



Good point Pies. I'd forgotten all about that trick - too many years spent driving modern cars!

Big Ian

335 posts

254 months

Wednesday 30th March 2005
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Harry, What temp thermo did you put in?

Harry Flashman

Original Poster:

21,342 posts

266 months

Wednesday 30th March 2005
quotequote all
Pies said:
Did you have the heater on?



Oh yes - made little difference!

Harry Flashman

Original Poster:

21,342 posts

266 months

Wednesday 30th March 2005
quotequote all
Big Ian said:
Harry, What temp thermo did you put in?


83 degrees - identical to the one that came out (standard Granada 2.9 part)

Pies

13,116 posts

280 months

Wednesday 30th March 2005
quotequote all
Harry Flashman said:

Pies said:
Did you have the heater on?




Oh yes - made little difference!


But this might have been what kept your car temp from going even higher

Harry Flashman

Original Poster:

21,342 posts

266 months

Thursday 31st March 2005
quotequote all
Nah - because when I first noticed it overheating I put the heater on - and she still boiled over.

Flushed the coolant system properly; was full of rubbish. Not sure that a certain TVR dealer who did the last full service a year ago actually bothered to change the coolant; not that impressed, to be honest. That coolant was mucky.

I shall be taking care of the car myself from now on - at least that way you know it's being done correctly and with care & attention...