Water temp light..normal?

[bobbymk11]

my old valver used to be 95 upto 115 depends on driving style

my current 8v ...on motorway sits about 88-90...in heavy traffic can creap upto about 100-105....seems to keep its self cooler than a valver..but has had engine re-build so maybe thats helping...as like new

[Goops]

Thanks Rubjonny and all,

if anyone was on the m25 today after 6pm, it was a valvers nightmare!! Drove 30miles in 1st and 2nd gear looking at the oil temp light every now and then! The water temp light flashed when i hit 114 engine oil temp, flashed for a few seconds then didnt come on again (sounds like im describing a UFO sighting i know)..

Man was I happy to see the m4, cruised and let the car cool down nice with the air flow 

[CHRIS_MC]

whether or not its relevant, my coolant was getting red hot and boiling, it turned out to be my head gasket, cost me a bit to have the head reskimmed and my valves re-cut

[rubjonny]

hmm, sounds more like the temp sensor is starting to go faulty, or the clocks!  If the clocks detect a low water condition, the light wont go off untill you stop the engine then start it again.  It might be your sensor has an intermittant internal short, or the wiring is earthing somewhere.  If the sensor or wire shorts this causes the light to flash and the needle to slowly rise to the max line, if the short only happens briefly it might not be enough to make the needle move a noticable ammount.

I'd start with checking the wiring along its length for damage, and if that checks out replace the sendor with another from the local scrappy

[Goops]

Thanks, Touchwood seems ok so far!  I understand the temp sensor/sender is inside the tank right? Is this reachable/changeable or would I look at simply replacing the whole tank? Will check the wires tommorow, apparently we have a rain free weekend! Might even give her a wash/wax for the placebo effect! 

[rubjonny]

the one in the tank is the level sender, the coolant temp sender is in the plastic flange on the front of the block, the black one

[Goops]

aha! 

Cheers, will check this out tommorow! Have a fantastic weekend 

[Bob Hewitt]

i've had this problem with both my current 8 valve gti's. on my '89 it was a faulty sensor - causing the red light to come on for no apparent reason (both water and oil temp ok). you could switch off the engine - and it would be fine when you started up again straight afterwards.
i've just started running a '90 gti as well - and today on an 80 mile round trip, when the oil temperature got to 102 degrees - the water temperature light strats to flicker!
now here's the strange part - on my '89, the water temp needle is bang in the middle - and never overheats - but is slow to warm up.
the '90 warms up quickly - but the needle is never more than up to the 1/4 mark (i've never seen this on a mk2 gti).
i spoke with the guys at wilsons of rhuddlan north wales - who have looked after my golfs for the past 20 years - and they said it was ok.
there will always be the odd faulty/sticky guage and sensor - or dodgy warning light - don't worry too much if the car is running ok - and shows no other problem signs.

[rubjonny]

whats the oil temp like on the one which only gets up to 1/4, could be a stuck open/missing thermostat?  Could just be an under-reading sender as well of course.

[Bob Hewitt]

before i had it serviced (this last week) the oil temp was running at 98 - but after the service it's higher - regularly at 100 and up to 106.
when i bought the car (ebay middle of november) the heater was not existant - and the guage never above 1/4 mark.
wilsons did a full service and safety check for me - and bryn (the mechanic who usually works on my cars) fixed up the heater for me (needed a good flush through the matrix etc). he said not to worry unduly about the guage - and the 'stat was ok.
i must admit, i'm really funny (read fanatical) about everything being right on my gti's - and we're now in the (sad?) position of having 'his ' n hers' 8v mk2 gti's - with my daughter running a mk3 (just washed my mouth out) 16v.
i still have my '87 broken for spares (when the engine expired) - and will always own/run a mk2 as long as i draw breath.
my tornado red '89 has covered 240,000 - and is as much a pleasure to drive now as ever.
the (newly aquired) '90 has 144,000 (but no power steering!!) and is very tidy- i'll try and post some pictures when the weather picks up.