Rapid overheating?

[Zonda_ 0]

Under normal driving the Vento's temperature never moves above 70 degrees however when you come to a stop and it idles for more that 30 seconds it will rise to 100 rapidly! I've never waited to see if it will keep on climbing, I've always whacked the heater to max and the fans to full. What could be causing it? Non functioning thermostat? If so how do I find/remove/check it?

[stusnook 0]

The Thermostat went on my Golf VR6. The symptoms were that it overheated to the point of boilover from the expansion bottle. The top hose coming from the radiator was too hot to touch, but the bottom hose, although hot was 'cool' enough to hold for a second or two. My guess would be that if you find the same (i.e. bottom hose if 'cool') then its the thermostat.

Word of warning. When I took mine to VW main dealer, they said it was the head gasket and that it would be approx £1,000!! I disagreed and got them to do just the thermostat at about £180 and it fixed the problem! Result!

(Note - only reason I went to main dealer is the first garage I went to said they couldn't find the thermostat, and the second one said that they couldn't find any problem! I suspect that its a bitch of a job to fit the thermostat hence the responses I got).

[thegoth 5]

I had a problem with mine that the fans wouldn't run when the engine was! So cooling was only generated by forward motion.

I traced it to only having 8V appearing at the temp sender/switch in the radiator. Ironic as it's only 6 inces from the positive terminal of the battery.

I bodged a wire direct from the battery ( with an inline fuse holder ) to the switch and it's been sweet since.

TG

[matth76 1]

The Thermostat went on my Golf VR6. The symptoms were that it overheated to the point of boilover from the expansion bottle. The top hose coming from the radiator was too hot to touch' date=' but the bottom hose, although hot was 'cool' enough to hold for a second or two. My guess would be that if you find the same (i.e. bottom hose if 'cool') then its the thermostat.

Word of warning. When I took mine to VW main dealer, they said it was the head gasket and that it would be approx £1,000!! I disagreed and got them to do just the thermostat at about £180 and it fixed the problem! Result!

(Note - only reason I went to main dealer is the first garage I went to said they couldn't find the thermostat, and the second one said that they couldn't find any problem! I suspect that its a bitch of a job to fit the thermostat hence the responses I got).

[/quote']

Had exactly the same problem. AA first saw my car and immediately though it was head gasket. The phirm immediately diagnosed the thermostat as one of the pipes from the thermostat was hot and the other was cold. Got it all done for a little over 50ish quid. Get it done asap as if the thermostat sticks fully you will grind to a halt fast risking engine damage. Mine fully stuck but I thankfully stopped in time without driving it anywhere.