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Oil cooler fan issue? Car running hot

pierrebear

Well-known member
Joined
27 Sep 2017
Messages
387
Hi everyone

Grateful for your thoughts or experience please...

Car normally never gets hotter than 9 o'clock on the oil temp gauge and always tends to stick around there or thereabouts. Today for the first time it went all the way to the top white line and even past it briefly - granted, I was stuck in terrible traffic. Then once I got moving it didn't really fall below 10 o'clock - top white line.

I've checked out https://www.pelicanparts.com/techarticles/pcar_com/oil_cooler_troubleshoot2.htm and ruled out both the relay and the fuse. It's also not the oil cooler as the driver's side front wing is boiling hot whilst the passenger side is much cooler. I also didn't feel any air from the bottom front vent on driver's side when contrasting it with the passenger side (where there was plenty of air blowing with the aircon on full).

Any ideas as to fixes, prices and whether this is a specialist job would be much appreciated.

Thanks in advance.

Pierre
 
Both the oil cooler and the AC condenser have two speed fans. Is the second high speed fan engaging on the cooler? Usually if the ballast resistor is knackered the fan defaults to high speed only as a fail safe.

There's a way of shorting the pins across the relay terminal for the oil fan to test both high and low speed. If these are OK then it could be something else. Has it got the right a mount of oil in it?

Have not got the terminal shorting details to hand but there should be a thread on here or on toreB site?
 
Thanks, Zingers. I was in too much of a flap earlier with one thing and another (not this!) to test both speeds on the fan but I'll give it a go now - as I think I've mentioned before I'm a complete newbie at anything technical!

There ought to be the right amount of oil in there. It was only serviced by Northway a few weeks ago and is dry underneath.
 
Have a read here and it explains the terminals to short from the relay https://p-car.com/diy/fan/

Sounds to me your high speed fan is not working as the heat through the vent when it runs will be like being in the wake of a jet engine :what:
 
The low speed fan wasn't working on mine which I was told would be the ballast resister or the ccu. After testing everything i narrowed it down to a bad relay, if I took the cover off the relay and manually operated the low speed contacts it worked fine but not when checking with the scan tool test sequence. I swapped the relay with the rear blower fan (which I had changed a couple of years ago when it fused permintaly on!) and it all worked properly confiming a bad relay was the cause. Maybe a bit of a random one but worth checking and cheap and easy fix :thumb:
 
I think the fan is not working at all - I tried swapping the AC and oil cooler relays but to no avail. Definitely not the thermostat as the wing gets hot when up to temp. Hopefully not too expensive a fix but think it might be above my head and worth booking in to the local Indy - not much choice over in Jersey but I just can't justify the additional time and money to get the car over to Blighty.
 
The fan resistors are a known problem. I would suggest to change both the condenser and oil cooler fan resistors while the front fender is off.

I would suggest to do a OBD diagnosis of the Climate Control Unit to reveal any problems with the oil temperature sensor.

Here's details on the how to test and repair the fans:
https://www.bergvillfx.com/fanresistor


Cheers,
Tore
 
Thanks, Tore! I think all of this has (predictably) gone over my head. I've booked it in with a local indy to diagnose the problem tomorrow morning and work out what parts are needed...will hopefully get sorted very shortly and I'll just have to avoid all traffic jams in the interim :frustrated:
 
Update (with huge thanks to the ever-brilliant Ray at Northway Porsche who helped over the telephone): fan was not engaging at all, whether at high or low speed. The mechanic jumped the circuits and confirmed that the high speed only was was engaging, meaning that the ballast resistor needs doing (relatively common, I gather?)

The fan is not coming on at all though, meaning that the fan switch next to the oil radiator also needs doing (I gather :dont know: )

Anyway, parts ordered and should hopefully be back to normal service very shortly. Thank you all for your comments and advice!
 
I seldom see problems with the oil temperature sensor, (it's not a switch) but this could of course be such a case. The way to go would be to measure the resistance of the sensor, and do a OBD diagnostic. The Climate Control Unit will produce a fault code if the sensor is not working. The measured temperature will also be possible to read out with the OBD tool.
Cheers,
Tore
 
pierrebear said:
Update (with huge thanks to the ever-brilliant Ray at Northway Porsche who helped over the telephone): fan was not engaging at all, whether at high or low speed. The mechanic jumped the circuits and confirmed that the high speed only was was engaging, meaning that the ballast resistor needs doing (relatively common, I gather?)

The fan is not coming on at all though, meaning that the fan switch next to the oil radiator also needs doing (I gather :dont know: )

Anyway, parts ordered and should hopefully be back to normal service very shortly. Thank you all for your comments and advice!

Hey Pierre,

Did you get this sorted?
What was it?

Thanks,
MaKS
 
Hi MaKS - did get it sorted, thanks. Ballast resistor was definitely shot so got that replaced. Additionally thermostat didn't appear to be opening because of something stuck in there - black plastic? Anyway, I did the repair as suggested in another thread by decgraham and all now working perfectly.
 
Hi there PB,
Would you possibly put a pic up on the thread of your oil temp gauge when it's currently running at its hottest?
It would be a good reference pic seeing as you've got all the oil cooling up front sorted.
Thanks!
B
(Mine sits JUST above the 9 o clock position when fully hot, I often wondered if it should be lower!)
 
Hi ballcock

I'm really confused to be fair...here's a pic after I'd just driven from Poole to Windsor going at a fair rate of knots the whole way earlier tonight. It never reached 9 o'clock but I think that was because of the amount of air it was getting fed.

I'll try to upload another one once I do get stuck in some traffic whixh shouldn't take too long!! Normally runs at 9pm exactly.
 

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Thanks PB,
Yes the pic I'm interested in is indeed when you've been stuck in traffic and the needle has hit its max temp, thanks!
 

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