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

Thermostat Sticking?
https://forums.tipec.net/viewtopic.php?f=25&t=7915		 Page 1 of 1
Author:  met [ Tue Feb 23, 2010 6:42 pm ]
Post subject:  Thermostat Sticking?
any help appreciated please folks, still waiting for my haynes manual to arrive. In the meantime my 944 cooling fan is running on for somewhat longer period of time after switching the engine off. I can get round it for now by pulling the fuse for 10mins or so and it resets. Please can someone tell me where the thermo switch is, guessing it needs a new un, is it easier to by pass it and run it from a seperate switch Kenlowe fashion? Also heard about the DME relay from a 968 as a good replacement as mine is a daily driver i could do with replacing I guess and keeping the current as a spare, where is the relay located and from eurocarparts is the Front Relay??? think thats what they call it?? thanks in advance, more questions to follow as i get used to my new car, loving it as a daily at the moment.
Author:  AlpineTurbo [ Tue Feb 23, 2010 7:25 pm ]
Post subject:  Re: Thermostat Sticking?
Thermoswitch is in the rad just below the top coolant hose. There is a guide on testing the relays and fans on Clark's Garage website. The fan staying on points initially to the thermoswitch or fan relay, usually the former is the first to fail.

Whilst a Kenlowe will do the job of engaging, it will only mask the problem that you have, which could get worse. Kenlowes are designed for cars which have a mechanical fan (and even then, there has been debate about whether the mechanical fans a better (Kenlowes are not what one would call efficient in terms of energy use). or where the original fans were very poor (I'm talking about the very first electric fans, ones like the on the first MGBs).

Other thing it could be is a shot radiator. It doesn't have to be leaking but if it is corroded from the outside, full of flies or even silted up inside from a lack of coolant changes, these factors would all help in your car not cooling down fast enough.
Author:  met [ Wed Feb 24, 2010 7:38 pm ]
Post subject:  Re: Thermostat Sticking?
ok update and some more help please. ordered a new fan switch, and its a 3 pin although i did order 2 pin as mine is 04/82 x reg. can i use a 2 pin? 2 big pins one small one in the middle?

2nd question is that fan was coming on at the right temp then staying on, then it went to not coming on at all unless i fiddled with the fuse. now its not coming on at all? any suggestions

assuing that i can use the 3 pin that ive been sent it looks a bit fiddly to get to, assuming i need a deep socket to sit over it rather than than trying to get a spanner on it as its under the mechanism for the pop up lights.

striped the regulator of the driver leccy window and found out that it wasnt the mechanism its the motr thats dead. so easy to work on (so far)
Author:  944BLOKE [ Wed Feb 24, 2010 9:25 pm ]
Post subject:  Re: Thermostat Sticking?
send it back! you need a 2 pin for your car. The fan will stay on after switching off the engine until it gets the temperature down again but does so at reduced speed.However,the fact that yours was working/not working as you fiddled with the fuse suggests you may need to clean the fuse terminals or replace the fuse or you could have a wiring problem at the fan e
nd rather than the radiator end.My fan (1984 model) comes in when the temp needle is between 12 and 1 o clock. :) edited to add the size of the nut on the thermo switch can vary .some are 30mm some are27mm.Ive always done the job from the top although some people prefer to remove the undertray and get at it from below. :)
Author:  t3rra [ Wed Feb 24, 2010 10:58 pm ]
Post subject:  Re: Thermostat Sticking?
Mine done this in d summer, once it just stayed on a few times I got in d habit, of pulling the large fuse out each time, till one time I left it in d box and drove 30mins home, lucky nothing bad happened. So then I left it on drivers seat. And one day it just stop playing up. Could be the out side temp. Or just tempermental.
Author:  lindsayhbrown [ Wed Feb 24, 2010 11:07 pm ]
Post subject:  Re: Thermostat Sticking?
my temp switch went short about 3 years ago, 2 pin one, cost about a tenner and about 10 mins to fit, caught spilt water and returned to header tank
Author:  AlpineTurbo [ Wed Feb 24, 2010 11:10 pm ]
Post subject:  Re: Thermostat Sticking?
Like Lindsay said, the thermoswitches can short, shown by the fans staying on. As said, the components can be ruled out by reading over Clark's guide and methodically testing the cooling items.
Author:  vince944red [ Thu Feb 25, 2010 10:50 am ]
Post subject:  Re: Thermostat Sticking?
I've had this problem on an 86
The radiator thermal switch can fail both ways, mine failed 'on' - easy to replace I did from top
Then it was clear the relay had also failed - this is harder to spot because the rad fan still comes on but at a lower speed - not really enough to be effective - it has to be a high pitched whine not a dull hum!

I had a complete chain of failures - the rad fan screws at the bottom of te radiator were not put in by previous owner, the fan blew against the engine pulley when driving and cut through the cables - not obvious when stationary, so had to replace the fan, then the thermal switch failed on, then the relay failed.
Author:  Aido [ Tue Jun 01, 2010 6:17 pm ]
Post subject:  Re: Thermostat Sticking?
Quote:
There is a guide on testing the relays and fans on Clark's Garage website. The fan staying on points initially to the thermoswitch or fan relay, usually the former is the first to fail.


Would someone kindly give me a link to this testing guide?

This just started happening to me today. I heard the fan when I pulled up the office but thought nothing of it thinking the car was cooling. It ran the battery flat.

Luckily I had some jump leads, but now home over an hour and have had to disconnect the battery.

I also noticed that the engine temp gauge didn't really move, kind of hangs around the 7 O'Clock mark, probably needs to be replaced also.

1991 944 Turbo 2.5
Author:  Lee 944 [ Tue Jun 01, 2010 6:56 pm ]
Post subject:  Re: Thermostat Sticking?
http://www.clarks-garage.com/ You get this in the resource section on the main TIPEC web site.

Go to garage shop manual on the left and then scroll down to "T".

If I've done this wrong, someone will be along in a moment to put you right.
Author:  Aido [ Tue Jun 01, 2010 9:31 pm ]
Post subject:  Re: Thermostat Sticking?
Thanks a mill :)
Page 1 of 1 All times are UTC
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/