temperature red light on dashboard - help needed!

Post by **Stokey Moonraker** » 24 Aug 2007, 09:17

Sorry to ask the dumb question....I really am useless when it comes to vehicle maintenance.

I have looked at Wiki and it helped to a point but I need help on what to do next.

I have a 1989 moonraker with a passat diesel 1.9td engine in it.

All was well until a recent service which left me with an engine that seems to be getting hot. I.e. after about 30mins the red light comes on (the one on the temperature guage).

I had an oil change at the service - so do I need to just top this up or is there a danger that something more serious is up.

All help greatly appreciated.

Post by **MacAoidh** » 24 Aug 2007, 09:44

Hello and welcome.
Have you checked the Buzzer of Doom info? It may be related.
Also, it might be worth amending the title of this thread, should help attract people who have knowledge in this area.
Hope you get it sorted!

Post by **tonytech** » 24 Aug 2007, 10:28

Does the temp guage go up before the light goes on?

Is the water level correct in the expansion tank?
There are two coolant tanks on Water boxers not sure about diesels. The one behind the flap is the top up tank.

Did the service include a coolant change? these vans are a little tricky to bleed the air out of.

I s your oil level low? Unless it is very low it wont affect cooling, but top it up.

Buzzer of doom is a water boxer thing.

T

Post by **Stokey Moonraker** » 24 Aug 2007, 10:40

temperature guage goes up - goes out of the intial thick white box on the guage and then ends up just to the left of the light - which only comes on after some time driving.

Have had the van for over a year and never had any issues like this - and although it still drives fine I am worried that if I ignore the red light something horrid will happen.

I'll top up the oil certainly - I had this changed and it just not have had enough put in I guess. I don't think he changed the coolant though.

Post by **purplechugster** » 24 Aug 2007, 13:39

tonytech wrote: There are two coolant tanks on Water boxers not sure about diesels. The one behind the flap is the top up tank.

Buzzer of doom is a water boxer thing.

Diesels are exactly the same - two tanks, and the one behind the number plate is just the one to fool you...

And diesels have the buzzer of doom too. You'd have mentioned it if it was going off so thats got to be a good sign

'Normal' running temp is anywhere on the dial above 'cold' and below 'hot', and the average is with the needle pretty much on the little red light, so it doesnt sound like you're running hot

Are you losing any coolant? Is it boiling over?

Post by **Stokey Moonraker** » 24 Aug 2007, 14:02

purplechugster wrote:
tonytech wrote: There are two coolant tanks on Water boxers not sure about diesels. The one behind the flap is the top up tank.

Buzzer of doom is a water boxer thing.

Diesels are exactly the same - two tanks, and the one behind the number plate is just the one to fool you...

And diesels have the buzzer of doom too. You'd have mentioned it if it was going off so thats got to be a good sign

'Normal' running temp is anywhere on the dial above 'cold' and below 'hot', and the average is with the needle pretty much on the little red light, so it doesnt sound like you're running hot

Are you losing any coolant? Is it boiling over?

So it doesn't sound like its overheating which is a relief - assuming the guage is correct. Now just need to work out why the red light is coming on!

I don't think I am loosing coolant and its certainly not boiling over that I can tell.....mystery to me.

Post by **camper** » 24 Aug 2007, 14:31

There are two tanks one is an expansion tank which is located in the engine compartment and a overflow tank behind the number plate.When you switch on for engine start there is an initial temp guage red light flashing .The red light is activated by a screw threaded black plastic electrode that screws into the expansion tank.The red light which come on when you start the van initially checks for coolent than goes out after a few seconds.If the red light is coming on after some time driving it could be a bad or corroded plug connection to the black plastic expansion tank probe or faulty.Buzzer of doom is is related to the printed curcuit board behind the speedo housing.Low oil preasure even a faulty board can activate the buzzer.

Post by **airhead** » 24 Aug 2007, 15:21

I have this problem from time to time. I have a small water leak. Occasionally if I wasnt careful the water would completely drain from the filler bottle behind the reg plate. Once this is empty the header tank in the engine bay will start to empty. Once this starts emptying the red light will come on. Filling the filler bottle wont usually help because for whatever reason the header tank has to be completely full before the filler tank can be filled. Ideally youre not supposed to let the filler tank empty and this will prevent you having to fill up the header tank. So what you need to do is pull the rubber hose off the cap on the header tank in the engine bay, undo the cap and fill the tank, replace the cap tightly and then replace the hose and fill the filler tank.

Post by **R0B** » 24 Aug 2007, 15:24

could well be a dodgy temp sender.there are two on the 1.6td engine.not sure how many on yours.

Post by **camper** » 24 Aug 2007, 15:30

Interested to no where the other temp sender is on the 1.6td..Thanks