The oil cooler on my GT is leaking, again. I replaced the orginial one back in 2001 with a good used cooler, now this one is leaking a small amount.
The placement of the cooler under the radiator makes it an easy target when the car hits going up a steep diveway. My ride height is at factory spec, so no "your car is to low" comments.
Has anyone moved their cooler from this location or added some additional protection? Maybe mount something the way the GTS has the transmission cooler near the top of the radiator.
Might be cheaper and out of harms way to just put in a Mocal cooler in front of the radiator w/ some AN lines, but I really want to keep the GT stock.
Any thoughts?

 

John,

My 91 S4 oil cooler has been leaking since I bought the car 1 year ago. A few drops a day. Engine uses/looses less than a quart in 4-5k mikes.

I have been thinking about repair / replacing mine recently.

One shop guy suggested taking the cooler to a radiator shop and having it repaired. I don't know about this since I am not sure where the leak is exactly.

I have also wondered just how important the thing is anyway. No autobahns in Arizona and I don't race it. With all of that oil capacity I wonder if the cooler is needed.

Have you replaced the cooler yourself? Is it much work?

Chuck
928quest
91' S4 Slate Grey/Grey

 

Hi,
yes, the cooler is needed as part of the 928's complete "cooling system" and should not be deleted. It contributes significantly to the engine's longevity

A metal type fly screen - not too restrictive - provides good protection from stones and other debris

Regards

 

I asked about the "little cooler" bottom center in front of the radiator last week. Got input that it's a transmission oil cooler? What's leaking out of yours: engine oil or ATF? Since I have coolers built into the radiator caps for oil on the driver's side and transmission on the passenger side: how does this extra cooler help?

 

Steve, the 90-91 GT (not sure about the S4) and I think all GTS cars have an oil cooler outside of the radiator. It's mounted to the bottom rad suport and hidden by the lower spoiler, maybe not thebest spot (JMHO).

John there are a bunch of mfg out there to chose from. Location? Thats a tough one. I have thought of putting it in front of the rad. and mod'ing the bumper cover and inner fender.

Cooler Vents

Fluiddyn

 

John,

There is a "terminal Piece" that fits under crossbrace in front of the radiator. It's there to direct airflow and protect your oil cooler. The front spoiler also provides damage protection.

The cooler operates using a thermostat, so oil flow only comes thru when the oil temperature exceeds the setting. Engine temperature is controlled by the engine coolant thermostat and radiator.

Most synthetic oils don't benefit by having the oil cooler installed because they have extremely good properties at higher temperatures.

 

Thanks for all of the replys.
I'm well aware of the location,function, cooling, and about oil. I cover those items for my day job and volunteer job.

My first cooler had a leak were the cooling tubes connect to the end cap. This leak was more than likely caused by the cooler being bounced a bit.
I did try and have it repaired with no luck.
Removing the cooler straight forward. Remove the belly pan, remove the oil line assembly and then a few bolts.
The lower spoiler offers some protection, but the cooler still gets pressure placed on it whenever the spoiler scrapes.
I wonder if a new one from Porsche is built differently than the orginal design.

 

-Earlier this year, I had trouble finding a radiator with an in-tank cooler for my '85 5 speed. I bought a non-cooler later model radiator and installed a Hayes oil cooler kit. It uses a sandwich plate under the oil filter, has a thermostat, and cost around $80. I had to buy a pair of plugs from Devek to cover the old oil ports.

It's mounted in front of the air conditioner condenser, behind the grill but in front of the fan.

Good luck-

Normy!
'85 S2 5 Speed

 

Hi,
Borland - the oil cooler is an integral part of the 928's cooling "system"- ( air flow circuit, coolant circuit and lubrication circuit ). The oil cooler thermostat opens at 87C and is a "secondary" component in the cooling system - air & coolant being primary. Once the coolant circuit is at full operating temperature and flow ( with the thermostat fully open at about 98C ) the role of the oil cooler in maintaining a viable engine temperature becomes absolute!

Without it, the 928's cooling system would eventually become disfunctional

An engine's "core" oil temperature in normal running is usually about 15C-20C above the coolant circuit's operating temperature. And it may be somewhat higher of course without an oil cooler

You are correct - synthetic engine oils do indeed usually tolerate very low and very high temperatures better than mineral oils of a similar viscosity.
However, all engine oils - both mineral and synthetic - operate best in a temperature "band" from about 80C to around 110C.

Synthetics - depending on their base oil's formulation - may still deteriorate rapidly if used for long periods at temperatures above about 130C

Regards