Declan 0 Posted May 8, 2003 I've got a bit of a problem. My C came back from a full service yesterday. She had a new Auxiliary Water Pump, some electrics done and all the usual oil change/ coolant drained etc. which was fine, but I've just managed to get her back from her maiden post service drive with a coolant temp. of about 125C/130C and oil at abou 104C. and at that temp she started to shudder at mid revs as if in protest. Could anyone tell me if you have ever experienced anything like this as I am going to send her back to the Garage tomorrow and if I can give them a few pointers it may make their lives a bit easier and the job a bit quicker/cheaper. Could it just be the thermostat? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted May 9, 2003 Jammed stat possibly, but most likely an air-lock was introduced when installing the electric pump. Not many people know this but the sure fire way of avoiding air-locks is to fill the coolant system through the radiator top hose, and *NOT* through the expansion tank. My stat was well and truly jammed and it's a real bast to change out. VR6's should sit at or just below 90 deg on the temp guage when healthy. They usually climb to 100 sitting in traffic but the twin fans should reign in any temps that go above that. Are your fans switching on? The engine will moan out of protest because the temp sensors will confuse the Motronic brain. Same happens when the engine is undercooled. it feels sluggish and hesitant at certain revs. Kev 94 VR6 Quote Share this post Link to post Share on other sites
Declan 0 Posted May 9, 2003 Thanks kevhaywire, That sounds promising. I think you're right, I think that when they fitted the pump something's happened to the stat. The fans did come on yesterday but not until about 110C. The garage is going to change the stat on Monday with a new VAG one and I'm hopeing that, that will do the trick. Thanks again Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted May 9, 2003 It isn't possible to disturb the stat when changing the aux pump but you may be unlucky in that the stat went during the operation! I'm glad the garage are doing the stat as I wouldn't wish that job on anyone! Luckily my radiator was out when I did mine so was a lot easier. Get them to test the new stat before putting it in as it's not unknown to have a new one not open. You have to keep an eye on VR6 temps as the heater matrix and the smaller hoses don't like getting too hot. Hope it gets sorted. Kev 94 VR6 Quote Share this post Link to post Share on other sites