Morning all

 

I've recently bought another MK2 1.3 coupe s and the temp gauge doesn't move what so ever. The car gets warm and blows warm air but I would like the gauge to work. Previous owner said it was intermittent before eventually failing completely. Does anyone have any ideas on where to look first?

 

Cheers, Dan

Take the wire off the sender unit and short it to the engine block/ground and the needle should go full scale hot with the ignition ON, if it does that will prove the wiring and the gauge, and that means the sensor has failed, if it doesn't move then either the wire to the speedo is open circuit or the gauge is faulty, does the fuel gauge work OK ? if not then you could be looking at the voltage stabiliser unit failed 

^ that will be the black sender...front corner of engine 

Thanks for that, nice little simple test! Would that be the sensor with the yellow wire?

front right corner of engine

37 minutes ago, dpalmer_220992 said:

Thanks for that, nice little simple test! Would that be the sensor with the yellow wire?

 

 

No those two sensors on the back of the cylinder head are the low oil pressure switches

Ahh right my bad haha! I think I know where you mean, the 2 sensors down on the front right are covered in oil so that could be something to do with the issue. I'll get them looked at on Wednesday hopefully but thanks a lot for your help!

The sensors are on the plastic housing near the thermostat. There are new ones available online. They have sliding plastic circlips which hold them in place. I don't know why there are two. Perhaps someone else could answer that question.

black is for dash gauge , blue is for ecu signal on the 2f

Edited 7 December, 20196 yr by steveo3002

The wire is prone to chafing at the plug as well. Might just want a new spade connector putting on.

Hi all, abit late to thing Thread but my coolant gauge is intermittent on my 1988 1.3 S , I’ve changed the sensor and sometimes when I give the dash a wack it moves again, the fuel gauge doesn’t work aswell. I’ve checked the fuel gauge actually works by shorting the plug on the sender and it moves. I’ve been told they’re prone to having a dodgy Motherboard on the dash but I’m not sure. 
 

Any ideas?

 

Thanks

Edited 19 April, 20224 yr by Michaelskinner

If giving it a whack makes a difference then it is almost certainly a loose connection somewhere - either an actual wire connector or a component loose on the board or in the gauge unit itself.  I would take the clocks out and do a quick visual exam and use contact  cleaner on the connector plugs.  If you see anything looking corroded, bad solder joints etc then its a clue to there being a fault.

 

You can short the temp gauge to test, like you did the fuel gauge, but only do it for a second or so as I burned out a gauge by holding it shorted for too long.  Ideally get someone else to look at the gauge as you make the contact to get a quick observation.

 

As your fuel gauge is operating when shorted at the sender's plug, but not in normal use then you may have a problem with the level sender itself, as you have just proven the gauge and wiring is OK.  It is possible for these level sender measuring floats to get stuck, or on some older models of car (not VW specific) the floats can perforate and get flooded and sink giving minimum gauge all the time.  Sloshing the tank by bouncing on the boot rim or generating high G-force through driving can sometimes free them up or make them move momentarily - worth trying as a last ditch before considering shelling out for a replacement.

 

Hi mate, 

 

Since this post I’ve changed the dash clocks as I was told about the voltage regulator which is a known fault, it was cheaper for me to do the whole clocks as aposed to the regulator itself. I had to change my speedo to the new clocks as the ones that come with it was out of sync with my car. Saying I was going 70mph when I wasn’t. 
 

I’ve also changed the fuel sender as the old one was burnt out, we tried to take it out and clean it up but I only read from half a tank down. When it had a full tank it read empty! 
 

So now I have a working fuel gauge & a working Coolant temperature gauge. The only thing is between 10-40mph the needle jumps slightly on the Speedo when it never did before so I’m thinking I need to lube up the Speedo cable as I’ve heard you can do that to help it. It never did it before I took the gauge out..
 

Thanks for your reply! 
 

Mike