Hi all... first of all, sorry if this is on the wrong thread... I've got absolutely no idea if my problem is mechanical, electrical or supernatural!
I've just bought a 1989 T25 1.7 diesel and had her in for a service today. Good news on the pennies front (just an oil change, new oil filters, easing of gears and a fiddle with the soon to need sorting clutch) but my mechanic is baffled by the flashing temperature gauge. He has checked the radiator and water levels and has suggested I seek advice from the boffins of the VW world! Is this a common problem? A quirk of the vehicle? or something more sinister lurking in undiscovered parts of the engine?
Hope someone can shed some light on what to do....
1989 VW High Top Kameo 1.7 diesel 5 speed AKA Betsy, my Beige Beauty
a key bit of information eh! Sorry, but I've got a very big learning curve ahead of me when it comes to engines.... my knowledge runs to checking oil and filling up the windscreen wiper bottles!
I drove her about 50 miles over the weekend with no problems but on the way to the garage yesterday, I'd only driven about 4 miles when the temperature gauge hit halfway and the red light started to flash. Same again today... drove about 4 miles, temp gauge got half way then the light started flashing. The old chap I bought it off did say that it did that sometimes but surely there is a reason... which I'd rather find out now rather than it turn into something expensive!
1989 VW High Top Kameo 1.7 diesel 5 speed AKA Betsy, my Beige Beauty
The flashing light is coming from a sensor on the header tank.
It warns of, low coolant level and high coolant temp.
If neither is happening I would suspect a failing sensor.
they are not expensive and available from Brickwerks
scroll down the page and choose the type you have clip on or push on.
before you buy however, when the light flashes take a look at the header tank (not the top up tank)... it should be full of coolant.. DO NOT REMOVE THE CAP.. just look through the plastic tank
If you can see a line of coolant then the system needs bleeding of air
if you have ruled out low coolant and high temp , another possible cause is poor earthing in the engine bay.....
take note if the coolant light flashes when you either brake , or flash headlights, turn headlights on, or indeed use any amount of power electrically ........ take the earth straps off and clean both ends of them and where they bolt down .
Also check the connections onto the temp sender and wires from it and the header tank , could be the insulation is damaged and touching earth.
one other thing... there is a relay..relay No 43 on the fuse board in position 3 (from left to right count three, top row for a post '86 van)
Might be worth changing that for a known good one (common to a lot of cars)
Haha... some houses do but not mine.... I've got my priorities in order and spent my savings on my first T25 instead of upgrading my living conditions!
With the wonders of the internet, I now know what a header tank is but am still baffled by the rest of the advice... I'm heading off to a local mechanics this week for a flash course in identifying engine parts!
My Beige Beauty has now 'developed' further problems too which I need to learn about.... like 'a lazy starter' (vocabulary I learnt of the nice AA man who came to our rescue on Friday evening on the way up to the lakes) and a worn cambelt, which will apparently cost me a lot of money if it snaps! It looks like I'm gonna be learning about T25 engines quicker than I anticipated!
1989 VW High Top Kameo 1.7 diesel 5 speed AKA Betsy, my Beige Beauty
guess its a diesel then, as petrol wbx engine dont have cam belts.
helps if you put what engine in your signature or at least in the posting! As it happenes makes no difference with the flashing light thing, but does with almost everything.......
header tank is inside engine bay, can only see with lid off , top up tank is behind numberplate flap.
The most important thing is to establish that the coolant level is correct and engine running within normal temp range when the LED is triggered. As stated, the VW Coolant LED can be triggered by low coolant or high temp and both have different wiring systems/components that are highly sensistive to poor connections and components. To establish wether the fault is in the Coolant temperature circuit or the coolant level warning circuit you need to do the following:-
1. Locate the module marked 43 (or 42) situated in the main fuse box under the glove compartment and make a note of its position.
2. When the LED starts flashing - park, switch engine off and remove the module.
3. Re-start engine, and observe LED for about 30 seconds or so. Continue with a short drive
If the LED continues to flash with the module removed the following need to be checked :- temperature issue due to low coolant, engine/timing, etc, an intermittent wiring fault in the temperature sender circuit, guage is not reading the correct temp, etc.
If the LED goes out after a few seconds and no longer flashes when driving with the module removed the fault is in the coolant Level warning system due to either of the following - low coolant level - faulty module 43 - poor earth connection - poor connection of the temp gauge centre nut to the ribbon cable - corroded prongs on the coolant level sender or poor connections to it.
Poor connections in the coolant level sytem wiring is a common problem. As Mocki points out there is an earth cnx in the engine bay and another located on a crown cluster next to the fuse box on the door pillar. Unfortunately, there are a whole bunch of earth spade terminals at the latter and best to check/clean them all. Even a poor battery earth, incorrect Anti-freeze mix can trigger the LED.
