After some chronic coolant problems on my MK2 jetta 8v pb, which I thought I'd cured, I had a breakdown the other day which involved a coolant hose splitting, losing all the coolant and then the engine temp to rise to 104 and the warning buzzer going, before I could pull over (terrible rush hour traffic etc). The car then wouldn't restart and a nice chap from the recovery firm temp repaired it, then continue my journey (but back home this time) All seemed fine but 1 mile further on, with oil and water both at the right levels and the engine temp at only approx 88, the buzzer came on again. It came on a further 4 times and I pulled over each time it happened, then I arrived home with a definate Sherman Tank sound, (although it sounded a lot better the following morning). So the thread is, do you think It's worth me pusuing a repair on what has been a very sound motor ?? Regards Gary
I could be wrong here, but I think the buzzer that you're hearing is not coolant over-temperature, but oil under-pressure. This may be what caused the original boil-up. It's also consistent with it sounding like a tank. First thing I'd be doing is dropping the sump off and checking that the pick-up gauze isn't choked up with sludge/debris. Whether or not any lasting damage has been done, I couldn't say. You may get away with it.
check the sensor on the filter housing with a yellow wire,. this will bring the oil pressure buzzer on, make sure wire is ok (pull boot back so can inspect the spade and wire fully) check sensor is not leaking oil
