Temp light flashing

Hmmm not used the car got a few days, so decided it was time to go for spin.
Started car all okay got down the road and seen temp light flashing.
So came home to check water level. That's okay turned car off light gone out restarted and same again looked at return pile to expansion tank nice flow back to there.

Just turned off again and all seems well again .
Any ideas?
Just gonna let her warm up to temp to see if fan kicks in.
Where is the switch got the temp gauge please and a piccy if what I am looking for would help lol.
It's cabby gti 1991 cheers

Chortle

Is the needle moving up to hot?

The one with the red and yellow single wire.

The needle goes to where it should be depending on temperature.
So the needle is ok.
My connection to that point on the flange is looking worse for wear gonna clean it up and see how we go.
Cheers Dan

Ah well it's wierd, it was flashing till the temp needle got halfway up then it stopped take it it's a new sensor time?
If so where from?

Cheers

Chortle

my white gti has the flashing light, have tried everything to get it to stop. just live with it now lol

Have a check on the rocker cover wire that can play up the temp gauge, I dont think it is the temp sensor as it would be playing up with the needle aswell. Had a prob with the wire on mine a couple of weeks ago and the needle would go to full hot and flash straight away, put a new spade connector on and all good.

^^

Yes check the rocker cover as earth problems are usually the cause of flashing light.

I had the other problem above which was max temp all the time (not a nice feeling when you've just rebuilt your engine- even if not actual overheating!) and a clean up with sandpaper of the sensor pictured above sorted this. Worth a go as well anyway.

Redid the earth on the rocker before but will double check and put a new spade on too.

On my MFA it's all good bar from when you scroll to the oil temp setting and it's only showing three dashes, no numbers where is the oil temp sensor located, may have to clean this up as well.

Cheers

Chortle

Which sensor puts the light on? My car has the hot light flashing randomly at different temperatures. I've confirmed the gauge is accurate enough by probe testing the water going into the rad and the fan comes on at 80 degrees.

It's the one lowest down in the picture red/ yellow stripe.

Righto thanks I shall replace that one and see if it makes any difference.

the light is also triggered by low coolant level, which is the 2 pin unit inside the header tank. note not all gtis have this the early ones dont. the low level warnign is controlled by the relay above the fusebox 42 or 43, these can gowrong but you can disable the whole system symply by pulling the relay out. to test if the sensor is to blame disconnect the plug on the header tank and bridge the pins.

while you're looking at the system check the pins and wires for corrosion, also unscrew the sensor and check the pins, if theyre dirty sometimes a quick buff up revives them. the sensors can go around the plug pins too, and coolant works its way up the level sender wires by capillery action, this rots out the relay and holder!

Thanks Johnny will have a check see.
One think I did notice is my expansion tank doesn't sit properly in it's bracket and the 2 wires going to the coolant sensor then are squashed flat from where the bonnet comes down on them. I reckon broken intermittent wire to the sensor.
Really need to go over the whole thing again.

I changed the circuit board on my clocks but had to remove the rev counter needle. I just put a fork under it and pulled it up and off, but on replacing it just flops down.
Have I busted it or is there something I should of done?

Cheers

Cjortle

sounds like the needle is worn where it attaches to the spindle, its a tight interference fit. the spindle is attached to a stepper motor so it shouldnt flow about liek the speedo needle does if that makes sense

Its most probably the circiut board behind the clocks.This is happening on mine,gauge is reading normal,fan cutting in as needed,replaced the relevant sensors no joy,eventually changed the instrument panel got rid of the flashing light but introduced other problems so re-fitted the original,another thing to add the light only fashes continually after i've restarted the engine when it is upto working temperature. If i drive any distance, long or short without stopping, the light will not flash.

I have had two different sets of clocks in the car and it does the same.

I am going to give the sensor a right good clean up and a new spade connector, then turn my attention to the coolant level sensor/ wires next.

Cheers

Chortle

Nothing like brining a post back from the dead…. apologies but was wondering if you sorted this as no final message on the posts.

I have just bought an 87 cab gti and previous owner said it's done it whole time he's had it, car reaches temp ok however light continuously flashes

Also randomly get the oil warning buzz but think it might be bad ground. (Stopped numerous times to double check the oil level) Will have a butchers but was hoping you could point me in right direction for engine temp light first 

Cheers

Do you have a fluid level in the middle of your expansion tank?  Is it connected?  Answer yes,  and you should remove the sensor and clean the tips then replace.

Other wise look for and replace grounds