Water light flashing randomly and high temp quickly when idling? Why?

[ScottMk2Gti16v]

Cheers guys. Not expecting anything to be seized - all 3 belts were changed just a few months ago so I guess any problems would have been dealt with then?

Just ordered a new water pump and alternator belt, should pick up tomorrow and hopefully get fitted on friday. Watch this space...

[Conker]

By the way, when they take off the old pump get them to check how many "fins" are still attached to the impeller, as the main reason they break apparently is the fins snapping off. If all loads of the fins are broken you can be fairly sure the pump was the problem!

[rubjonny]

the light also warns of overheat, so it could be the engine is actually overheating.  If you suspect the sensor.  if its a 16v check on the side of the head, there are 3 sensors there and they're all the same.  swap the red/yellow wire (dash gauge) to another sensor and see if symptoms persist!

[mattneck(Beavis)]

guy came into my work and had this also.. turned out to be the black sender for gauge and light on dash.

[ScottMk2Gti16v]

The plot thickens...

Got the water pump changed and it didn't make any difference. If only I'd got my new mechanic to look at it first (I'd already got a water pump ready before going to him) I'd be ahead of where I am now!

It turns out we think the actual gauge itself is faulty (either the gauge and/or the printed circuit panel behind). And the radiator was full of sh!te, AND the cylnder head gasket needs done! Obviously with the radiator not working properly and the head gasket needing done, the temp will be high, but it's so random up and down and all over the place we think there's a problem with the gauge/circuit to it. Might also explain why my dash lights also don't work.

So a new radiator an head gasket are on the way and it's getting done in a couple of weeks. I'm also replace the circuit panel on the dash and maybe the temp gauge itself (with all other clocks if it has to be done together)....this is my problem now..I've got a spare mk2 gti 16v golf that I'm going to rob the bits I need for the dash-
I haven't had a chance to look yet, but how easy is it to get the dash off? Think I remember it as having to almost take the whole dash off by finding the various screws, etc but I've never been in about the clocks. Is there a guide anywhere to keep me right? Or any secret screws I need a tip off about?

Nightmare getting online just now to as I've moved and getting wireless soon, and my employer (local council!) has banned all forum use on it's network!!

[Khare]

I had a similar problem, turned out it was the gauges fault. It was a loose wire or something, cos it starting flashing, then the fuel and temperature gauge died, then i would just give the clocks a little push into the dash and they would be up and running again. Havent had this for a while now. Have a look at the clocks mate.

[Goops]

Hiya Mate,

I have been down a "similarish" route, and have tried absolutely everthing bar replacing the clocks and still have a flashing light!
Guess thats next on the list..

G

[Notis_kr_16v]

anything new about the prob?

[ScottMk2Gti16v]

Well that's the motor all sorted AT LAST! 

Picked it up yesterday after it has just had new (in addition to water pump and expansion tank in previous weeks):

• Cylinder head gasket
• Radiator
• Instrument cluster

Thankfully I managed to get the instrument cluster out my spare golf easy enough and it worked fine when connected up, for the first time in a while I've got a fully working cluster. My car has also just lost 32000 miles, going down from 175k to 143k! I've no intention of abusing this fact though, not least because I'm never selling the car.

Anyway so to summarise my problem:
Radiator and head gasket needed done - these problems alone will obviously cause problems with the temperature.
BUT
My temp gauge was faulty also - so while we knew the car was overheating, the reading was clearly false on the gauge - i.e. max temp INSTANTLY when stating car then up and down like a yo yo. Guy looking at it say's 100% it was gone and that's been proved now it's changed. Other one works perfect. No flashing red light, no dodgy temp and all is cool.

5 or 600 quid later + a lot of stress and I'm problem free again! For now.....

[rubjonny]

just to add, this symptom can also be caused by a faulty temp sender, or the temp gauge wire earthing on something intermittantly