1.8T Overheating?????

[happyarthur1979]

Hey guys,
I know this has been covered before but cant find a difinitive answer to my problem.
My car has started overheating. I replaced thermostat and temp sensor about 8 weeks ago. Car gets to operating temp as normal then creeps up. Hose from the thermostat housing to bottom of radiator stays cold throughout while other hoses get hot.
Car is a 2000 1.8T Aum with just over 80k.
Could this be a faulty thermostat? Or something worse like the water pump?
Is there any test I can perform to check the if the water pump is u/s?
Many Thanks, Graham.

 

[abdus]

have you checked coolant level?

what temperature does it sit?

 

[TheSpaceCowboy]

Looking at it logically it would seem as though the waterpump is knackered. If one side of the cooling system is cold and the other piping hot its not pumping the water to dissipate the heat?

 

[HTC]

Start the engine and look at the coolant expansion bottle. There should be a jet of coolant squirting in from the small top hose. Get a friend to rev the engine up to 2000rpm. If you see no jet, then the pump is most likely fugged.

 

[happyarthur1979]

Thanks guys,

Start the engine and look at the coolant expansion bottle. There should be a jet of coolant squirting in from the small top hose. Get a friend to rev the engine up to 2000rpm. If you see no jet, then the pump is most likely fugged.

Should I do this at operating temp or will it be the same from cold?

Thanks Again!

 

[HTC]

It will be the same at any temp.

 

[happyarthur1979]

It will be the same at any temp.

Ok cheers,
I have just gone out and at operating temp with expantion cap off I increaded the revs to between 2 and 3k and there IS coolant returning to the tank via the small top hose.

Would this mean the water pump is ok as there is coolant being pumped around the system?

Could it be a that the thermostat is stuck closed?

EDIT: ITS THE AGU ENGINE NOT AUM.....

Thanks Again, Graham.

 

[bredhurststeve]

if it of any help mine was the water pump even though it was pumping water through the return into the expantion tank,

 

[abdus]

when was the cambelt and water pump done?

 

[happyarthur1979]

Ok Cheers,
Gonna remove the thermostat tomorrow and use the old 'cup of hot water' trick to see if it opens.
If not ill replace it, if it does ill have to put the car in and get it checked.

 

[HTC]

Does it overheat in slow traffic or when you are driving at higher revs?

Maybe the pump impellor is slipping on its shaft?

Whilst you have the thermostat out, you can shine a torch in a check the condition of the pump.

Maybe you have been unlucky and the new thermostat is faulty. Happens from time to time.

 

[Dubplate]

just a thought....Is the fan coming on ? i had a similar problem on my corrado which turned out to be knackered bearings on the fan which caused it to intermittently switch off when the engine was hot.

 

[HTC]

Good call. Check the fan.