Today my vRS was running very hot, it got almost to the red at about 115 degrees or so before I ran the interior fan to clear some heat.

 

When I got it back and started it again and running about 90 degrees, took the coolant cap off and it started to boil out of the bottle.

 

I noticed the radiator fan only ran when the car was running and switched off when I turned the engine off, most cars I have the fan runs on when its turned off including my Golf Mk2. Not sure what thats about.

 

Anyway, am I right to suspect headgasket failure? or would the radiator be blocked or would have the water pump failed? any other ideas.

 

Theres no mayo on the oil cap, seems to be driving ok during normal driving but dont want to drive it too hard when the temps are so high.

I'd actually suspect the radiator fan thermo-switch of having failed. It should have cut in before the gauge got to 115C!

 

One of the fans runs low speed whenever the AC is on, so that may be what you're seeing as "fan running"?

 

As to the engine boiling when you take the lid off the expansion vessel, you've just opened the pressurised circuit, so of course it boils!!

 

Water pump failure is also possible; when was it last changed since their life on the 1.8T is about 1.5x the cambelt?

 

If HGF continues to be a concern, get a coolant gas analysis (about £15).

The belt and pump was changed at 65k and theres now 105k on it.

 

I could hear 'a' fan running when I was in slow traffic.

 

Brought it to my local mechanic for a quick look and used a blue dye test, it came back green so its not looking good :thumbdown:

Edited 8 November, 20169 yr by cormac81

The belt and pump was changed at 65k and theres now 105k on it.

 

I could hear 'a' fan running when I was in slow traffic.

 

Brought it to my local mechanic for a quick look and used a blue dye test, it came back green so its not looking good :thumbdown:

Ah, that does look like it actually is HGF then. :( I was trying to rule out all the cheaper stuff first (I'd get a new water pump and belt kit fitted when the gasket is being changed, since the old belt will have to come off).

really unusual to get HGF but if they have tested it then really bad luck.

not herd of a head gasket fail on these yet..... my bet is still on the water pump.....

not herd of a head gasket fail on these yet..... my bet is still on the water pump.....

HGF is rare these days, but the OP has had a positive dye test for it.

Feel your pain, recently purchased my mk1 vrs with 98k on the clock with a failed headgasket. granted it was £400 however on removal of the head ive found quite abit of play in the valves between 0.5 and 1mm side to side :( 

going to have the head skimmed, valves re ground and the seats re cut and have the stem guides and seals replaced at the same time just to be 100% on the rebuild 

 

are you doing the job yourself or getting a garage to do the re build ? 

Feel your pain, recently purchased my mk1 vrs with 98k on the clock with a failed headgasket. granted it was £400 however on removal of the head ive found quite abit of play in the valves between 0.5 and 1mm side to side :(

going to have the head skimmed, valves re ground and the seats re cut and have the stem guides and seals replaced at the same time just to be 100% on the rebuild 

 

are you doing the job yourself or getting a garage to do the re build ? 

 

Havent had the car long but it did seem to creep up from no where. Hopefully get a mechanic to strip and get an engineering firm to do the head..

 

Going to get a timing belt and water pump at the same time.

Well I got the thermostat replaced with a new genuine VA part 3 weeks ago and the car has behaved perfectly ever since!

 

Fingers crossed!

On 07/12/2016 at 17:02, cormac81 said:

Well I got the thermostat replaced with a new genuine VA part 3 weeks ago and the car has behaved perfectly ever since!

 

Fingers crossed!

I have the exact same thing gone wrong with my Octy mk1 vrs... 

Overheating badly  110+ degrees, I suspected water pump failure but after having it go in the garage, the mechanic said they dye/pressure tested it and the colour had changed! He said headgasket failure and that il need to have it sent off to be skimmed, new water pump and cam belt kit. 

 

There's no mayo, the coolant hasn't gone down and no other obvious signs to be HGF. 

 

The car drives absolutely fine with no faults other than the temp running high when sat in traffic and returns to 90 degrees when moving 40mph+.

 

What I really want to know is did the thermostat permanently fix the issue or did it come back???

 

The cars only done 113k, very well looked after with ful service history right up to about 2 months ago 

The thermostat did the trick, no longer have the car but it behaved perfectly after. Temperature stayed at a constant 90 when warmed up.

 

 

Had the thermostat replaced yesterday...so far no issues at all, temperature sitting at 90 as usual 🙂 so glad I found this thread before considering scrapping her!