temp guage/temp sensor??

[stevencolman1]

hi. ive just bought my first porsche, an 87 944 2.5 lux. i'm having problems with the temperature guage, it reads ok (normal temp) for a bit and then suddenly jumps up into the red then drops back to normal. sometimes its stayed in the red for 5 mins and then suddenly dropped back to normal.
i would just like to ask if anyone has had similar problems? could it be a faulty guage or one of the temp sensors as ive been told there are two?!?

help would be much appreciated as it scares me a bit seeing the guage in the red even thow its not overheating.

thanks

 

[stevencolman1]

anybody any ideas?

 

[Frenchy]

Steve,
Not sure where the sensors are on your car but that would be my first stop check the wiring on the plugs , after that take a look at the rear of the dash binnacle for dodgy earth wiring.

 

[stevencolman1]

thanks. i'll check these and report back

 

[DavidL]

Steven,
I have exactly the same problem and yes it drives me mad although I have had the car 8 months and haven't sorted it yet!
Check the following:
Earth points and leads especially the main one from battery to body. I have a check sheet for earth points somewhere I'll dig it out.
A new sender is fairly inexpensive so I shall change that anyway and take the dash out and check all the connections to the gauge - Clarks garage has a good step by step to taking the dash out and its really isnt too hard - just don't break your nosr taking the steering wheel out!
I might rewire the sender to the dash rather than try to find the frayed wire in the bulkhead somethere - can't help feeling it is going to be easier and cheaper than trying to chech what is there already.
Again Clarks shows a way of checking your temp by connecting the sender to a multi meter, havent tried this yet. I could do with an external temp gauge to check when the car is running, I might ask my indie about some options.
You can get new (used) gauges too so that may be an option if that is where the problem is.
Mainly check your fans operate and see if the gauge shows any change, mine thends too even if it is playing up beforehand.
When I find the cause for mine I'll let you know and perhaps you wouldn't mind doing the same.
David

 

[stevencolman1]

fixed the temp guage today [] i took the clocks out and took the two pronged piece out of the back of the guage, cleaned and re-fitted it and hey presto. works fine now. thanks for your help guys []