Coolant Temp Warning Light/Rev Counter Problem................

[illumin]

Yet another problem today, I'm sure my car hates me...........

When the engine is running, the coolant temp red dash light is flashing. At the same time, the rev counter needle goes up and down for no apparent reason. This continues for a minute, then everything goes back to normal. Minutes later it happens again..............

My (uneducated!) guess is that the blue temp sensor is behind this - am I right? No apparent coolant loss, engine is hot (but it always is), temp gauge reading normal. 1991 8v Digifant.

Can I still drive the car until I get the sensor replaced, or will that kill the engine/cooling system (main concern - head gasket)?

[rubjonny]

blue temp sender is for the ECU so nothing to do with it

More likely to be the level sender in the tank thats gone, or you haven't got enough coolant   Check the level then unplug the sender & bridge the pins.  If it still does it then you may have a problem with the clocks or wiring, especially if the rev counter is going at the same time?  Check the earth lead from the rocker cover to the coil braket, if this is loose/missing it makes your clocks throw a wobbly

If that all looks OK, take the clocks out and make sure all the nuts round the back are there & done up tight, check for loose or missing earth cables then check the voltage stabiliser:

Cconnect a voltmeter between the terminals shown (see illustration) with a 12 volt supply to the remaining terminal. A constant voltage of 10 volts must be registered. If the voltage is above 10.5 volts or below 9.5 volts renew the voltage stabiliser.

[illumin]

Thanks for the info rubjonny. I did discover something today that may have been the cause (I am so cr*p with cars!). One of the plug leads fell out of the dizzy cap, I replaced them recently and obviously didn't put the new one in properly..........you mentioned loose connections sending the dash funny - could a loose plug lead have been the culprit as it hasn't happened again since the lead was put in properly........I am so dumb I should be blonde............. :embarassed:

[wolfman]

These are the symptoms of the Motometer clocks problem. If you have a late model with Motormeter rev counter this could be the fault. Only seems to affect late clocks i.e, those with the single connector. The early clocks with two connectors are different internallyl.

If this is the problem then the symptoms will get worse i.e., the flashing will happen continuously and the rev counter will rise and fall independently of the engine speed all the time. Eventually both will pack up. The MFA is also affected. The rev counter is the culprit. Best solution is to get replacement clocks from a breaker and swap your rev counter. From memory, a new one from VAG is in excess of £200. VDO also made the rev counter for this vintage but they seem to be thin on the ground although I have heard that they are more reliable. If you can get one they are just a straight swap for the Motormeter unit. In both cases the rev counter must be from late clocks with the single connector.

[illumin]

Thanks for that Wolfman - got some clocks today but think they are the early type - they are VDO though. Before I take my dash to bits would it be possible to remove the VDO rev counter mechanism to replace the Motometer item?  I presumed that the basic mechanicals would be the same.....The clocks I got today so have two connectors, but I thought they were worth picking up anyway. I guess the circuit board on the older clocks is useless to me as well, surely there is something I can salvage from the older unit?.........maybe have to go searching scrappies again.....

[illumin]

Got some clocks but they were the two pin sort so of no use whatsoever! Took my clocks out and checked them over, everything looks ok tbh - nothing obviously broken. On a possibly related note, last night my alarm went mental and wouldn't turn off - had to rip it out to shut it up! I'm beginning to think that the electrics may be dodgy.........

Had a look at the earth strap that attachs to the rocker cover - it has a big kink in it, may even be broken under the plastic cover (going to investigate further this morning). How many more earth straps are there? I know there is another big one attached to the gearbox, but are there any more? Just want to eliminate them before I try and get hold of new clocks, which are bound to be dear......................

[illumin]

Earth strap going to the rocker cover was a state to say the least! Once I undid the bolt attaching to the rocker cover I discovered that instead of the "eye" type connector, there was no connector - a hole had been made in the strap and it had been forced over the bolt! Replaced that one and everything started working again for a while, but went back to playing up. Have since noticed that the earth strap between the bonnet and inner wing is ropey as well, so have to replace that one too, and see if it makes a difference............

One thing though - could the very dodgy earth strap removed from the rocker cover have caused permanent damage to the clocks unit? I have no idea how it has been like that, but can't imagine it was doing the clocks any favours.......

[naut2k5]

Bah, I hate earth straps ! 

http://www.golfgtiforum.co.uk/index.php?topic=26520.0

Currently having earth strap problems - did yu manage to check under the kinked part of the earth wires to your rocker cover? Im yet to do that but Im wonder if that would cause a problem! 

Im noticing all my lights are coming on over the dash but I have another problem compared to yours!

Let us know what you find!

Jim 

[illumin]

Bah, I hate earth straps ! 

http://www.golfgtiforum.co.uk/index.php?topic=26520.0

Currently having earth strap problems - did yu manage to check under the kinked part of the earth wires to your rocker cover? Im yet to do that but Im wonder if that would cause a problem! 

Im noticing all my lights are coming on over the dash but I have another problem compared to yours!

Let us know what you find!

Jim 

Hey naut2k5 - Ended up changing the earth strap to the rocker cover and the one between the bonnet and inner wing. Both the old ones were in a state. Rocker cover one was missing the eyelet connection, strap had just had a hole forced into it with the bolt. Bonnet-inner wing one had virtually fallen apart at one end. Replacement straps were only a couple of quid each and the new ones are much thicker, so worth doing. Didn't solve the f*cking dash clocks problem though! I think the dodgy earths have killed the clocks!  Bloody car!

Btw, do you know if there are more than 3 earth straps (rocker, bonnet and main one to gearbox)?

[naut2k5]

Where did you get your straps dood ... i've been advised to whack on the longer gearbox earthstrap that not only go from the gearbox mount but direct to the gearbox , might solve my current problem but shall see.

Not sure if there are others - the ones you mention sound about right - can anyone confrm ?   

Oh and where in the SE are you ? Anywhere near Dartford ? It was you that said you were in the SE right ? 

I wonder if my clocks are buggered to as when I go to start her all the lights come on 

Off to Paris now with the gf, back in 2days!