Thermostat or water pump?
Thermostat or water pump?
Author
Discussion

Alex200mph

Original Poster:

510 posts

281 months

Friday 17th May 2002
quotequote all
Hello
The old cooling problems which come more critical as the weather gets hotter!
I have a 94 pre serpentine chim which is running really hot . I have checked the usal things like correct water level, air pockets in the radiater, fan belt tension. the two electric fans working etc.
so must be one of two things I think:
1.Thermosat jammed closed or near to closed
2.Water pump is defective, probably the bearings.
So:
1. Where is the thermosat? is it easy to remove? Then I can test it and see if thats the problem.
2. How can you test the water pump without removing it (I can take the fan belt off easily if this helps).
If anybody can help it would be much appreciated so I can enjoy the nice weather. Its not in the SH bibel see!
Thanks

zippy500

1,883 posts

285 months

Friday 17th May 2002
quotequote all
What sort of temperature are you getting. Do the fans cut in around 92. Can you here gugling in yuor heater system, could be an air lock.

Alex200mph

Original Poster:

510 posts

281 months

Friday 17th May 2002
quotequote all
zippy
Took it out last night and just gentle 50 - 60 mph in top was producing 92 - 100! Too hot I think, I was having to use the cockpit heater to take heat off the engine. I took the bleed nut off the radiator and no air cane out just a mix of water and anti-freeze. The fans are working fine, I have even hardwired them so they are on from the moment the ignition is turned, and the car is still running hot. At tick over the turning over of the belt is not super quiet. but this is hard to tell.

zippy500

1,883 posts

285 months

Friday 17th May 2002
quotequote all
Yes id say you have a problem, it could possibly be the gauge or sensor. Id test your thermostat before hand though.

Alex200mph

Original Poster:

510 posts

281 months

Friday 17th May 2002
quotequote all
Thanks zippy and quinny
I don't think that its the temp gauge since when you pull the bonnet up after a run its running so much hotter than it ever use to. I will remove and test the thermostat and see if its that, and I will test the water pump by hand with the belt off and see if its ok when I get home tonight. Will let you know the result
Thanks guys

zippy500

1,883 posts

285 months

Friday 17th May 2002
quotequote all
If you can feel lots of heat sounds a bit worrying im afraid. Hope its the themostat. Good luck

Paul V

4,489 posts

293 months

Friday 17th May 2002
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Does sound like a thermostat, a bit of advice, they are usually no more than £10, if your taking it out don’t bother to test it just replace it.

xain

261 posts

293 months

Friday 17th May 2002
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Alex,
I don't think the rad is the best place to bleed the system, it's too low.

The best practise seems to be to put the car facing up a hill, open the swirl pot (MAKE SURE IT'S COLD! and don't open the expansion chamber cap), run the engine, and keep the swirl chamber topped up until the fans have kicked in a couple of times. Then refit the cap.

That should clear any airlocks.

Also, if the thermostat isn't opening then the rad should not get hot, the fans won't run etc etc. Check that too.

Jon

>> Edited by xain on Friday 17th May 16:25

Driller

8,310 posts

294 months

Friday 17th May 2002
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Alex, I just had the rad replaced on my 3 year old griff and it's running 5 or so degrees cooler. I think rads get clogged up very easily from calcium in tap water. I only use distilled now. Something to think about...