Newbie still: Radiator fan issue.

[Austin87]

87 924S - My 2 radiator fans are only coming on with the AC switched on.

Here is story. 1) I am in south Florida. PO I bought the car from did not have any thermostat in the water pump. I took the car to a Porsche tech in Miami to replace my hose to the water pump / upper radiator and he installed just a gasket. Said in South FL on these cars it is better to not have a thermostat in. He also told me I needed to replace the radiator fan switch which I did.

2) I took the car last week to my regular indy mechanic for him to check the switch and tamp gauge to see if it was accurate or not. He used a laser temp gun checking hoses etc....and my fans came on & he also said my temp was normal but my gauge was not showing accurate readings which the PO also told me probably was so through the 5 yrs he owned the car.

--- Since then I am driving the car quite a bit and have not seen the fans come on 1 time w/o the AC running. Per Clark's garage the fans should engage at around 92 degrees which they definitely do not do.

It would be nice if I could do this myself and not have to take it in. Any suggestions where to start? Does the missing thermostat have anything to do with the fans not coming on?? I do not have a coolant leak that is noticeable at all from any drips but I do get some coolant odor into the AC sometimes.. sometimes I do not.

Thanks...

[87m491]

Couple things. Running no thermostat may not give your coolant enough time in the radiator to sufficiently cool, conversely it may take much longer for the coolant to get up to proper engine operating temp. That said, you mentioned he checked temps but you did not say what they were! Is the car getting up in temp enough to trigger the fans? If so I would check the coolant temp switch to start.

[flash75]

The 92 degrees mentioned is 92C not 92F. The fans don't normally operate while driving in moderate temperature weather. They will come on while sitting in traffic or when the car isn't
moving. In your #2 note you said the fans did come on when your mechanic checked them?

lf your engine is overheating leaving the thermostat out does not prevent overheating, it just takes a little longer.

Clifton

[Austin87]

Originally Posted by flash75

The 92 degrees mentioned is 92C not 92F. The fans don't normally operate while driving in moderate temperature weather. They will come on while sitting in traffic or when the car isn't
moving. In your #2 note you said the fans did come on when your mechanic checked them?

lf your engine is overheating leaving the thermostat out does not prevent overheating, it just takes a little longer.

Clifton

Clifton

This is the gauge I have in my car & the fans do not come on at 92C. & even though it's October the temperature here is hot. It got up to 89F and sunny today. With the laser gun the reading was 186F pointed at the water pump with the car idling for a good 10+ minutes. ( In well above 90F weather.)

* I have not overheated. When my gauge reads 97C w/o the AC unit on, like at a stop light it will get this high, I turn on the AC for the fans to get going. If I do not turn on the AC then the temp gauge will continue to read hotter.

[Austin87]

Originally Posted by 87m491

Couple things. Running no thermostat may not give your coolant enough time in the radiator to sufficiently cool, conversely it may take much longer for the coolant to get up to proper engine operating temp. That said, you mentioned he checked temps but you did not say what they were! Is the car getting up in temp enough to trigger the fans? If so I would check the coolant temp switch to start.

The coolant temp sensor was changed by the PO and if I understand correctly a bad temp sensor would cause the car to idle poorly and my engine runs smooth always.

Far as the missing thermostat can this be keeping the fans from turning on even at 97 C or higher ???

Thanks, Austin.

[9FF]

If your fans dont come on except with the AC on you definately have a problem. If you can smell even a hint of coolant inside your car you have a leak.

I've always run with a thermostat in SoFL and have normal temperatures and fan operation, so something with your car is certainly wrong.

I would get the correct thermostat put back in and find/cure the leak first. Ensure the coolant tank cap is the correct one, swap out the fan relay with a known good one and bleed the system. That's a good starting point and if the fans still don't come on you have to get the multimeter out and check wiring.

You have a great resource & knowledge just minutes away from you in Fort Laurderdale. Look up Mike Gokey at German Performance and pay him a visit. He will fix it and you will learn a lot about your car.

BTW Austin, I got your message but was traveling this weekend so couldn't meet up to help.

[smokin_944]

Austin, I recommend trouble-shooting the cooling system of your car. Clark's garage explains how to go about it. In your case follow the same procedure as the early 944 cars as I believe your 924S is the same as far as cooling. Go step by step and you will discover the problem.

[Austin87]

Originally Posted by smokin_944

Austin, I recommend trouble-shooting the cooling system of your car. Clark's garage explains how to go about it. In your case follow the same procedure as the early 944 cars as I believe your 924S is the same as far as cooling. Go step by step and you will discover the problem.

Clarks Garage is great if you know where all these thing are that they mention.

[tamathumper]

Agreed, things are sometimes hard to find in the PDFs, and there are actually a few PDFs that are broken or hidden. You can either download every PDF and index it with EverNote as I have done, or use Google to search the site... Something like:

"Cooling System Troubleshooting site:www.clarks-garage.com"

[Austin87]

Originally Posted by tamathumper

Agreed, things are sometimes hard to find in the PDFs, and there are actually a few PDFs that are broken or hidden. You can either download every PDF and index it with EverNote as I have done, or use Google to search the site... Something like:

"Cooling System Troubleshooting site:www.clarks-garage.com"

I meant that I am not familiar knowing where the parts that CLarks mentions are located on my actual car. I tried describing as best as I can above what issues there are . I just replaced the Fan Switch & the PO also replaced the Temp Sensor on the top of the engine.

So I guess it may best to take this in to a good indy like Mike mentioned above....
...

[tamathumper]

Oops, my bad.

A little of the fun is finding where all these things are, and the Parts Manual (PET) is sometimes helpful - it shows mostly what is connected to what, even if not exactly where it is located on the car.

[smokin_944]

Ah I see the problem. Ok Austin go to TS-02, Troubleshooting - Cooling system, scroll down to the bottom of the page where you see COOL - 01 and click on the link. All the info pertaining to early cars should apply to your car. Follow the steps in order and you will probably find your problem.

[smokin_944]

To get there (TS-02)use the search engine and enter cooling problems. Let me know how you fare.

[Austin87]

Got a tip on Rennlist i most likely have a bad fan blower relay. Cannot budge the one that is in there now. Are they welded in normally? Is there a relay release tab somewhere ??

[Austin87]

Originally Posted by smokin_944

To get there (TS-02)use the search engine and enter cooling problems. Let me know how you fare.

Hi Smokin, According to Clarks pic of the cooling fan relay is below ( pic 1 ) and according to parts for this car the part is ( pic 2 ) totally different.. Where is the difference coming from ?

Thanks, Austin

[tamathumper]

I think he means he can find it on the web page, he just can't find it on the car.

Austin, to answer an earlier question, a bad DME temp sensor will usually make your car run poorly (a little rich) at idle, but fine after warming up.

What parts, in particular, do you need help finding under the hood?

[tamathumper]

The lower picture is a relay. The upper picture is of someone holding the electrical connection to the thermofan switch that's located on the driver's side of the radiator (at least on my 968).

[tamathumper]

The relay will come out, but it will take some convincing. Take a picture of the fuse box as a close-up documentation of where everything is and what direction it's pointed in.

Remove whatever other relays and fuses are in the way to make room around it.

If you have a piece of "router mat", or "shelf liner", or one of those floppy "jar opener" things, use that to get a good grip on the relay.

Pull straight up.

If necessary, us a thin, non-metallic "spudge" to get under the edge and carefully pry up on one side just a bit, then on the opposite side, and "walk" it out of the contacts.

[smokin_944]

Pic 1 that you posted is of the thermal switch connector for the later car *(85/02) not a relay. It has 3 pins because the thermal switch for later cars has 3 prongs. The early cars have thermal switches with 2 pins. Pic 2 is of a relay of some kind. Hope this helps.

[Austin87]

Originally Posted by Austin87

...............According to Clarks pic of the cooling fan relay is below ( pic 1 )

Thanks, Austin

so ...According to Clarks pic of the cooling fan relay is below ( pic 1 )