Removing thermostat altogether

[Jay]

Car started to overheat yesterday

Spoke to a mechanic today who seemed to think the stats gone. He suggested removing it altogether. He said he's done this to his VW for the summer.

I Didn't even think it was safe or possible to run without this.

Anyone know what the pro's or cons of removing it?

 

[<tuffty/>]

Ermm, don't... simples

 

[Mr V]

By removing the thermostat, the engine will take longer to warm up, this will in turn cause the engine to use more fuel as it'll be on cold start for longer. I really don't see the point, i'd also be looking for another mechanic to look after my car.

 

[Imteyaz]

Chances are the stat won't be at fault.... water pump impeller failures are also common too. VW/Audi's are engineered to run at a certain temperature range, I would be compelled to change the stat first, if that fails, change the temp sender (also common) then failing that the waterpump is the last item to change (along with a new timing belt / tensioners at the same time as it would only take a few more minutes whilst doing the job).

 

[ian52]

if he went to the hassle of taking his out why not just put a new one in while its in bits?

 

[jimbobery]

As above, removing the stat is not the way to go. When they fail they get stuck open and the temp heats up and then goes down when cruising as the water flows round all the time, by removing it you'd just be introducing this fault.

You can check if your temp sender is at fault faily easily. If you've got climate control you can get the unit to display the water temp. This doesn't come from the temp sender, so for example if your dash says 100 and the climate control says 70 its likely to be the temp sender, but if they stay the same (they're not always exactly the same) then the problem lies elsewhere.

Do a search for checking temp in climate control, if I find the thread I'll post it here.

 

[Mr V]

Chances are the stat won't be at fault.... water pump impeller failures are also common too. VW/Audi's are engineered to run at a certain temperature range, I would be compelled to change the stat first, if that fails, change the temp sender (also common) then failing that the waterpump is the last item to change (along with a new timing belt / tensioners at the same time as it would only take a few more minutes whilst doing the job).

All of those faults are pretty easy to diagnose - there's no need to guessafix it. Jay just needs to find himself a decent mechanic.

 

[Jay]

Was kinda confused when he suggested this too. Especially since I replaced the stat and sender about a year ago. Personally I thought it was the water pump but he said we would have been able to hear a knackered water pump. He took it for a drive and pulled over when it started overheating and checked the hoses coming off the radiator, one was red hot and the other was cold, I think he said the bottom of the radiator was cold. what does that suggest?

Been driving with the CC temp display on (no.49) got upto 120 degrees!!! normally sits between 90 and 100.

Gonna pay him a visit on the weekend as i've asked him to get a stat for me. Suppose its easier/cheaper than replacing the water pump straightaway!!

 

[ljames]

hey sounds like your water pump blades are snapped.common fault on these engines.vw,audi,seat fit plastic impellor on them for some reason,but if you get a replacement from a factors they usually come with metal ones.I went down the road of changing the thermo with my mates seat ibiza,but was def the water pump.You will not hear if the water pump has gone,lol.you can only tell by removing it......

 

[Mr V]

He took it for a drive and pulled over when it started overheating and checked the hoses coming off the radiator, one was red hot and the other was cold, I think he said the bottom of the radiator was cold. what does that suggest?

That would suggest either the thermostat is stuck closed but that'd be unlikey as it's been changed before. Or the water pump impeller has failed and isn't pumping the coolant around the engine. I've changed many water pumps that haven't been noisey but the impeller has broken.

 

[Jay]

thanks for the suggestions guys. How much are water pumps?

I know that the thermostats definately been changed under a year ago.

Looks like a long job, checking both stat and then maybe onto the waterpump.
Just want it fixed so I dont have to drive the family Almera!

update - just had a look under the bonnet and noticed the coolants disappeared but can't see any trace of it not even a drop under the car??? where has it gone???