Club 80-90 Forums

Hi all

Im having some odd temperature problems in my 85 1.9 water-cooled T25. Basically when I start the engine the temperature gauge shoots up and the light flashes like crazy, if I turn the engine off and start her up again all is well and the temperature gauge behaves as normal (slowly rises to about half way and stays there, no light after the flashes when you turn the key to position one), the van is running fine otherwise.

I have recently had the wiring to the thermostat replaced by my local mechanic as the they had corroded and where making the temperature gauge give false readings. After this little job the van ran without issue until now.

I have also recently changed the oil, filter and rocker covers.

Im completely stumped as to why the temperature gauge would behave in this way and was hoping that someone would be able to shed some light on the situation.

Thanks

John

Hi John

Could be a few things at fault here but as a general rule of thumb when you are getting strange, spurious electrical faults it is often down to some sort of earthing problem. Some things you could check are:

1. Inspect and clean the earthing crowns (located on the inside of the A-pillar, in front of the front door, above the fusebox on my left-hand drive, and above the glove box on a right hand drive.) They are a little bit fiddly to access but you should manage to remove each of the connectors and then rub down each of the spade earthing terminals. You can give them a wee spray of contact cleaner if you have it.

2. Replace the temperature sensor. Only a few quid from brickwerks.

3. Remove the instrument panel display and check that the main 14pin connector is clean and properly connected. A loose connection or dodgy wire here could cause the gauge to behave strangely.

4. Make sure the coolant system is fully bled. See the wiki for advice on how best to do this.

I'm sure someone else will have some other ideas for you and hopefully will be along soon! Good luck, hope you get it sorted

Henry

Thanks Henry. I had a feeling it would be an electrical gremlin, I will start hunting it out over the weekend. Hopefully its nothing too major as I'm off to a kent VW show next week, nothing like arriving in a cloud of steam with the van making strange and worrying noises

Pull out relay 42/43, a fault there could affect the temp gauge, it will remove the coolant level sensor from the possibilities, and it's easy to do.

Hi guys so today I was attempting to drive home in the van and the temperature gauge was playing up and not settling like normal. So I pulled over and had a little poke around in the engine bay just to make sure nothing was seriously wrong.

Well it turns out that the cap on the coolant tank was not completely tight and the valve was a bit gunked up. So after a quick clean up and a tighten my temperature gauge is behaving as it should.

Hopefully that was a nice easy fix for a pesky problem. I will go ahead and do a coolant change anyway as its been on the maintenance lost for awhile now.