Porsche Enthusiasts Club Forum
https://forums.tipec.net/

Temperature gauge
https://forums.tipec.net/viewtopic.php?f=25&t=5192		 Page 1 of 1
Author:  deacs [ Sat Jul 25, 2009 10:00 am ]
Post subject:  Temperature gauge
I have slight issues with the temperature on my 1983 944........

Normally the car runs at the 1st quarter to 1/2 mark on teh temperature gauge but as soon as you stop in traffic the gauge quickly climbs up until the start of the end(red) marker on the temp gauge at which point the cooling fan kicks in and the temp drops back marginally.

Im sure this isnt right as the temp seems to climb very fast as soon as the car is stationary, could this possibly be air in the system?

at what point on your temp gauge does your fan kick in?
Author:  Brett928S2 [ Sat Jul 25, 2009 10:49 am ]
Post subject:  Re: Temperature gauge
deacs wrote:
I have slight issues with the temperature on my 1983 944........

Normally the car runs at the 1st quarter to 1/2 mark on teh temperature gauge but as soon as you stop in traffic the gauge quickly climbs up until the start of the end(red) marker on the temp gauge at which point the cooling fan kicks in and the temp drops back marginally.

Im sure this isnt right as the temp seems to climb very fast as soon as the car is stationary, could this possibly be air in the system?

at what point on your temp gauge does your fan kick in?


Hi :)

The gauge is working properly from your description but the fan is cutting in too late...

First check the water level....and no it is NOT air in the system.....then check the terminals are CLEAN AND SHINY on the fan switch....the other thing you could do is either change the fan switch or bridge the wires so it runs constantly or fit a toggle switch to the dash , so you can manually turn it on when needed...

All the best Brett :)
Author:  deacs [ Sat Jul 25, 2009 11:29 am ]
Post subject:  Re: Temperature gauge
I was questioning the gauge as it seems to hop about a bit when it gets higher up the scale and if you give the top of the dash a whack with your hand the needle hops about.

water level is fine, never uses any water at all.

so at what stage on the gauge does your fan usually cut in?

where would one find the fan switch?
Author:  David924S [ Sat Jul 25, 2009 11:36 am ]
Post subject:  Re: Temperature gauge
From memory the fan switch is on the bottom right hand side of the radiator when looking into the bonnet, easier to get to if you remove the air box and mounting brackets. There are some cheap fan switches about that switch at the wrong temperature and you may have one of these I think again from memory the fan switch range should be 80 100 degC. But I might be wrong, the range is normally marked on the switch they are not expensive to replace £15-17 I think and are eaasy to replace if you have a deep socket to fit over the terminals think it is 30mm socket.
Author:  deacs [ Sat Jul 25, 2009 11:42 am ]
Post subject:  Re: Temperature gauge
yep agreed that its worth changing although my main issue is not so much when the fan comes on but how the temp suddenly climbs when the car is stationary or moving in slow traffic. litterally goes from 1/4 on the gauge to 3/4 in under a minute. to me this isnt normal (ive had 40 cars including lots of old bmws)
Author:  Brett928S2 [ Sat Jul 25, 2009 11:50 am ]
Post subject:  Re: Temperature gauge
deacs wrote:
yep agreed that its worth changing although my main issue is not so much when the fan comes on but how the temp suddenly climbs when the car is stationary or moving in slow traffic. litterally goes from 1/4 on the gauge to 3/4 in under a minute. to me this isnt normal (ive had 40 cars including lots of old bmws)



Hi :)

Hmm....mine is around half way on the gauge (928) and takes around 10 minutes to climb to around 3/4 when the fans cut in....

You may have a bad earth behind the dash if clouting the dash affects it...

I would still think its the fan switch or temp sender though...

All the best Brett :)
Author:  deacs [ Sat Jul 25, 2009 12:10 pm ]
Post subject:  Re: Temperature gauge
yes im deffo thinking the gauges maybe suspect to some degree as giving them a tap seems to make the fuel gauge shift about a bit too. I think for now il wire the fan into a switch just for safetys sake, I really dont wanna go cooking the headgasket, ive been there too many times before on old german motors (merc 190's and E30 bmws!!)
Author:  J.J. [ Sat Jul 25, 2009 1:44 pm ]
Post subject:  Re: Temperature gauge
How long have you had the car & was it always this way? Does it have a service history? Might be gauge. Might also be that the water pumps dying. Impeller can slip on the shaft. Should have new pump every other belt change. Is it still pressurised? I don't mean take the cap off when it's hot! But after 30 minutes & be careful. Could also be that the radiator is full of CXXp. Flush & refill with new antifreeze. (Will need bleeding.) Should be done periodically anyway.
Gauge never reads more than thickness of the needle above quarter on mine. When stationary you can hear the fan cutting in & out & see the gauge respond. If it gets to the red then the engines goosed! You can get another gauge on ebay but I wouldnt run it until your sure. Easy to get at it on yours!

edit. Not wanting to be a doom merchant but whenever anythings gone wrong on mine it's been the expensive option. If it doesn't overheat when driven hard then the pump may be ok. At tickover it shouldnt slip so much! Hope it's the gauge!
Author:  deacs [ Sat Jul 25, 2009 9:52 pm ]
Post subject:  Re: Temperature gauge
under general driving and giving it some it doesnt overheat or run hot at all. yes the coolant systems pressurises as it should and doesnt seem to overpressurise. on a run or on the motorway it stays at under a quarter,

I personally think i have issues with my gauges as the petrol level warning light comes on when the fuel gauge still shows a good quarter of a tank

is it possible that my instrument cluster has a bad earth or the like?
Author:  J.J. [ Sun Jul 26, 2009 2:51 pm ]
Post subject:  Re: Temperature gauge
If the gauge works correctly when at speed then why is it screwing up at idle? Somthing not right somewhere. Is the thermostat working properly. Not too dificult to remove & you can check it with a kettle. But replace the fan switch first in the rad' You don't need to drain it just leave the cap on & do it stone cold. You will lose very little coolant. Could be it's just triggering the fan too late when the cars hot. If you lift the bonnet it should smell hot. The top hose would be burning hot! You can tell. I wouldn't drive it until it's sorted.
Author:  lindsayhbrown [ Sun Jul 26, 2009 9:44 pm ]
Post subject:  Re: Temperature gauge
rad thermo switch is a cheap first fix, known to fail, and about a tenner to buy and a half hour fix
Author:  944BLOKE [ Tue Jul 28, 2009 12:11 am ]
Post subject:  Re: Temperature gauge
Hi deacs,Ive had this problem and was told that the fan switch can deteriorate and not switch the fan on at the correct time so Ive just replaced it but havent used the car enough yet to know if its significantly different.I know the feeling,every time you get in a traffic jam the temp needle goes all the way over to "bleeding hot".not good! Its an easy job to do and you probably only lose about a pint or so of coolant so no need to re bleed the system.Interestingly I bought mine from Porsche-apart for £18 +vat & postage,asked for Tipec discount and was told "er that is the discounted price".didnt have time to shop around so bought it but found out later that Type 911 do it for £10.00! Guess where I ll be getting my parts from in future? The size of spanner/socket you need varies ,some are 30mm but this one was 27mm. I th
ink I will fit a switch as well then I will have control over the situation if the needle heads towards meltdown!! :) also,the job is a whole lot easier if you unfasten the air filter box and just move it out of the way while you change the fan switch. :)
Author:  deacs [ Tue Jul 28, 2009 5:58 pm ]
Post subject:  Re: Temperature gauge
have you let the car run up to temp since fitting the switch to see where the fan now cuts in? ive hard wired the fan in for a min and will take it out for a spin later to see how it reacts with the fan permently on,

Ive ordered a switch from the supplier you mentioned. their prices are excellent
Author:  944BLOKE [ Tue Jul 28, 2009 11:35 pm ]
Post subject:  Re: Temperature gauge
Yes but only in my back yard,not on the road.It seemed to come on earlier so hopefully this will sort it! :)
Page 1 of 1 All times are UTC
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/