Sudden overheating.. ideas please!

[mullermn]

Hi,

Bad news today.. While sat in a queue on the commute home I suddenly got an ACC deactivated warning as well as an engine warning light and the coolant temperature started rising. Stopping the car and turning the ignition off and on did nothing to clear the problem as it has for the odd error light I've had before. I made it the 20 or so minutes home with the temperature fluctuating but staying very high (but not in the red).

Turned the car off and let it cool a bit but the problem is still present. Coolant level is fine, and I can see the fluid circulating to the expansion tank. In my driveway test the radiator fan did not come on - not sure if it should but given that the temperature is high I thought it might?

The car is a 63 plate PP GTI. Never had any issues previously.

It's still under VW warranty but the local dealer won't take it as an urgent case if it isn't brought to them by a recovery company, and the first appointment they have is over 2 weeks away!

If anyone has any suggestions or relevant experiences that'd be great. At the moment it looks like I'm going to have to wait a fortnight and limp it in to the dealer?

Thanks,
Andy

[Watts]

That's a pita and likely rather inconvenient! Any other dealers within a reasonable distance that might take it earlier? Or if you have recovery cover, just drive it and 'break down' and get it towed in! I needed a wheel bearing replacing on mine and it was over three weeks just to get it checked and confirmed followed by another two weeks to get it replaced but at least I could use the car (other than long distance) so I fell your frustration. 

[RDC]

Had exactly the same thing about 6 months ago. I thought VW told me it was a sensor but looking at the invoice they replaced the coolant temperature control valve. Was covered by warranty otherwise would of cost £600. Not sure why the ACC deactivates but it did on mine as well.

I had no problem getting the car in the next day with my dealer but they weren't going to able to give me a courtesy. I did have a moan up with the service manager and they sorted me a car. Took 2 days to sort as the part had to be ordered in.

[mullermn]

That's really interesting, thanks. The ACC seems to deactivate at the slightest provocation so I don't think it means much in itself. The rising temperature and engine warning that won't clear is what's worrying me.

Luckily I do have the extended warranty.

I might call them back tomorrow and see if I can make a case for a more urgent appointment. The car is basically un-driveable at present. I'm fairly sure I can limp it to the garage because it'll take that long for the engine to reach temperature anyway.

I've also ordered an OBD diagnostic dongle off Amazon. Not sure it'll tell me anything useful but I thought it was worth a look.

[fredgroves]

Acc will deactivate because for the car to control the throttle during overheating would mean vw would be responsible for an engine seize I guess...

[mullermn]

Had exactly the same thing about 6 months ago. I thought VW told me it was a sensor but looking at the invoice they replaced the coolant temperature control valve. Was covered by warranty otherwise would of cost £600.

Sounds pretty similar then - I used a cheapy OBD dongle from Amazon and it found a P2556 code called 'Engine Coolant Level Sensor/Switch Circuit' so perhaps it's the same thing. I can't find any specific info online for VWs or Golfs but the generic description could fit what happened to you.

Incidentally, I got the wife to call the dealer back and tell them that 1) we're a 1 car family and 2) we have a 5 month old baby and they still refused to offer any more urgent appointment. I'll remember that the next time I'm deciding where to spend £30k on a car.

[RDC]

That's really poor. I brought my car from Citygate and I could of taken my car to either Little Chalfont or Watford my 2 local dealers the next day. Just had to kick up a fuss for a courtesy car.

The service department and sales team seem to really crap themselves that they do not get a poor report back after VW customer services get in contact after a service. I have mentioned that to them in the past when not getting the right answers, seems to work.

[uzinusa]

Hi. I think what happened to my PP last year sounds similar to your predicament: http://www.golfgtiforum.co.uk/index.php?topic=278889.0

They did it under warranty but I was non the less surprised that this could fail in <3yrs.  All fine now for me. I'm sure you'll soon be sorted, let us know.

[mullermn]

Update, for the benefit of anyone who searches for this problem in future.

Dealer have had it in since yesterday and have diagnosed the fault as:
'coolant light on dash relating to coolant bypass valve sticking require new thermostat with seals and possible water pump'

They don't have all the parts in stock so expect to need the car until tomorrow afternoon.

The repair is covered under the 'named components' extended warranty.

[monsta]

Just resurrecting this thread, my water temperature gauge sky rocketed this morning after sitting in traffic (Had ACC sensor intermittent sensor errors  in the past few days too) and I got a check engine light and warning come up saying I shouldn't go above 4,000 rpm.

My OBD Eleven reports the following codes;

P268100
P255600
P00B700

The first one was logged as malfunctioning 16 times so guess that's the real fault.  Myllermn was it just the thermostat or was the water pump replacement required?