front oil cooler switch question

[Red87911]

I've had my '87 911 for a couple of years now, and am going through the process of replacing old or non-working parts. My next job is replacing the short oil lines from the hard line to the radiator, replacing the fan with a Spal unit, and replacing the fan switch with the popular Febi Bilstein unit. My question is regarding which fan switch to use (or if it even matters at all):

01102 - temp switch @ 90°C
03280 - temp switch @ 75°C

It may be a dumb question, so please don't flame me as I'm a new owner and am new at working on my own car in the garage. TIA

[IROC]

Well, if you choose the 75C switch, it will essentially be on all the time as you will rarely every be below 80C once the engine is warmed up. 90C is better, and probably what I would choose given those two choices. I'm not familiar with the factory Carrera coolers, but I think those fans come on at temps much higher than 90C.

When I had a fender mounted Mocal cooler and a Spal fan, I installed a toggle switch in the dash so I could turn the fan on when I wanted/needed to.

YMMV.

[GH85Carrera]

Personally I would want one to come on at 90C. My 85 Carrera came with no fan at all, just the cooler. I added a fan and just ran a toggle switch. I usually flip it on at 93C or 200 degrees on my oil temp gauge.

80C is way too low.

[76FJ55]

The factory switch turns the fan on at 118C according to the manual.

[GH85Carrera]

Originally Posted by 76FJ55

The factory switch turns the fan on at 118C according to the manual.

Yea, that is when it is already "too damn hot" for my tastes. That is 244 F and just dang hot. If I know I am going to be driving for a long time, like a long road trip I will turn the fan on at 190 to help keep the temps lower for as long as possible.

Even at 70 MPH on the highway the fan does indeed help keep the oil temp down.

I have done real world tests while on a long road trip through 100+ sunny days. At 70 the temp will climb up to 240F with no fan running. Turn on the fan and it drops to 225F and does not go up.

Of course I do understand the factory does know more about the cars than I do. But they designed one very pitiful AC system for 100 degrees days. I think the factory oil cooling temps are not ideal.

My AC works after spending money at Griffiths. My oil stays cool after my modifications.

[Red87911]

I can always count on this community for a quick reply with good advice. Thanks guys - I'll stick with the 90°C switch.

[cmcfaul]

damn...244 degrees....on the highway?. Does the fan block air flow when not on? My 89 with no fan does not get nearly that hot ever.

Chris

89 Carrera

[Sebscst]

My fan came with an adjustable temp switch. Have you looked into those.

[911pcars]

One option is to use a manual switch.

Procedure: Look at the thermometer or oil temp. gauge, then flick the switch ON or OFF accordingly.

However, this requires some knowledge of installing a conveniently located switch, routing two wires to the electric fan, then connecting to the fuse box, switch and ground - basic rocket science and well within DIY levels of any competent auto repair shop. A relay would add further refinement to this circuit.

Sherwood

[darrin]

red87911 -- what's causing you to replace your oil cooler fan? Did it fail? another option here is to leave the thermostat as-is and install a switch to let you manually activate the fan at lower temp -- see https://www.pelicanparts.com/techarticles/101_Projects_Porsche_911/26-Oil_Cooler/26-Oil_Cooler.htm for info on where to wire this in.

[Reiver]

I simply put a toggle switch under the dash so control the on/off as I choose.....

[Red87911]

Originally Posted by darrin

red87911 -- what's causing you to replace your oil cooler fan? Did it fail? another option here is to leave the thermostat as-is and install a switch to let you manually activate the fan at lower temp -- see https://www.pelicanparts.com/techarticles/101_Projects_Porsche_911/26-Oil_Cooler/26-Oil_Cooler.htm for info on where to wire this in.

Yeah I believe the fan failed. I was sitting in traffic and the oil temps got waaaay to hot for my liking. I pulled the cooler and fan assembly, checked the fan and it was pretty much useless. An oem fan is like $450 while a Spal is less than $70 shipped. Figured I'd replace the fan temp switch too. Thanks for the link

[darrin]

gotchya -- have you confirmed that the hard lines and front oil cooler are, in fact, getting hot? Hard lines can/do get crimped and engine-side thermostat (that sends oil to front cooler when open) can get stuck shut.

[Red87911]

@darrin - good question. I have checked the hard lines, and the only area that was slightly compressed was towards the front jack point where a PO dented it.

I'm not sure how to eval the oil thermostat located in the rear fender. If it is malfunctioning can it be rebuilt, or does it require a new replacement?