Hi all,
On the way to work today the coolant overtemp light came on and I noticed the temp was almost maxed out. I turned on my heater full blast and stoped. Checked for leaks and coolant level and found no leaks and level was perfect. The fans were on and the serpanteen(?) belt is on and good. I turned off the engine for about 5 min. I decided to try to get off the freeway. When I turned on the car the temp was in the normal range with the needle right in the middle. So I thought the overtemp condition could have been an false reading. After about a minute the temp just shot up to almost max. Made it off the freeway to a gas station.
Double checked everything andall looked good except I could hear what sounded like water boiling. So the car isactually overheating.

Let the car sit a bit opened the reservoir.Coolant level was normal untilI took the top off. Then itoverflowed. Checked thewater hose coming from the bottom of the radiator and it seemed to be warm, but not hot. Also it seemed to be thinner than it should be like it was undervacuum. I turned the car on and temp was ok for about 5 minutes then it started to go up again. Got towed home.

My questionsare what should I look for? I think either the thermastat is stuck or the water pump failed.Does anyone know how I could checkthem? Also the car has over 103k miles and is close to needing a belt replacement. If it is the waterpump is ittoo much more work to replace the timing belt? Does any one have orknow where I can get a procedure for it? What repaire manual is recommended for this car?

Thanks in advance for your response.

Ernie

 

probably the water pump
they have plastic impellers on them
with the car coold down pull the small hose to the resivor bottle off and have her start the car see if the coolant flows out of the hose
if it dosnt the pump is bad
if it does rev it up a little and see if it flows faster or stops flowing
if it stops flowing the impeller has just started to come apart

 

yeah or thermastat, if it failed while closed, the hot coolant has no where to go to cool off. just continues to heat up

 

Yea I would agree, it's a good idea to change your thermostat every so often anyways. It's easier then changing the water pump I would say.

 

OK so here is what happened. I tried what Jrailer suggested and nothing came out. I figuered, car has 100k+mi and will need a timing belt. While in there might as well replace the water pump and thermastat and drive belt.

That was a job and a half! Lift the engine, remove the motor mount, work from the passenger side wheel well...

Found the pump was the problem. Impeller was broken in half. Replaced timing belt, water pump, and thermastat. Flushed the cooling system and installed new coolant. To top it off I removed the #1 cylinder to hook up the pressure checker to find tdc and damaged the wire. Ended up replacing the spak plugs and wires......Not cheap.

Oh well....Replaced wipers. Got air filter and oil and filter also. Will do that this weekend.

I have a question for you guys. Volkswagen says to use only the red extended life coolant. The couple of parts stores I went to adviced me on using the extended life green coolant. I did but I want to know if I did the right thing. Should I worry about and flush and replace again or will it be ok? Are extended life green coolants coprable to the red stuff?

Ernie

 

The Green stuff gels up the sytem. I ALWAYS get my coolant from VW dealer, little expensive but less than changing coolant system. I get everything from the dealer just to be safe.

 

glad to help
you should be ok it just dosnt last as long (extended life) but it still does the job