Porsche Enthusiasts Club Forum

I was wondering if there is any advantage to an external oil cooler instead of the coolant bath version on the 944 Lux?

I have the filter block from a Turbo engine, and was thinking of converting it at the next oil change, using a 'universal' radiator and having a set of braided hoses made up, obviously that will cost, just wondering if its worth it.

I know it doesn't remove the troublesome O rings, but what about bearing life etc...

Cheers.

Pete.

It would be an interesting project Pete but I can't help feeling it's a little overkill, a turbo has a lot more stress to deal with through the box, higher acceleration forces and a much higher top speed, also bear in mind that Porsche themselves decided it wasn't required on later Turbo models. Having said all that if it makes you happy then why the hell not, it'll certainly be a talking point for you at any future 944 meets...

Pete

I'd second what Pete said; don't bother. The 2.5 N/A is a pretty relaxed engine and won't need that degree of cooling.

The other point that no-one seems to spot with external oil-to-air coolers is that they slow the rate at which the engine heats up. Even when cold, oil is pushed through the cooler. With the oil-to-water coolers the cooling doesn't start until the thermostat opens and water is passed through the radiator. This allows a quicker warm-up rate and less engine wear while so doing.

If you think you need more cooling in the car then fit a bigger radiator, don't try fitting extra oil coolers. And no, I wouldn't bother with a bigger radiator either!


Oli.

hmm...just reread what the OP said after reading Oli's reply...sorry guys I thought we were talking gearbox external cooler??

me bad...

[quote="zcacogp"]I'd second what Pete said; don't bother. The 2.5 N/A is a pretty relaxed engine and won't need that degree of cooling.

The other point that no-one seems to spot with external oil-to-air coolers is that they slow the rate at which the engine heats up. Even when cold, oil is pushed through the cooler. With the oil-to-water coolers the cooling doesn't start until the thermostat opens and water is passed through the radiator. This allows a quicker warm-up rate and less engine wear while so doing.

If you think you need more cooling in the car then fit a bigger radiator, don't try fitting extra oil coolers. And no, I wouldn't bother with a bigger radiator either!


Oli.[/quote

Sorry Oli - have to disagree: the external oil cooler on later models is controlled by an internal valve thermostat, within the modified housing oil/water thermo block. It is closed until the oil reaches it's operating temp. No oil goes to the external cooler when cold. It is possible that oil heats up quicker than water, hence engine friction, so thence an external and more efficient oil cooler...? Porsche PET has the details of the two...

Dave

Dave
CT

You can find the complete unit ie cooler, hoses and housing unit on e-bay under "944 S2/Turbo parts" . You just have to renew the gasket and a few oil seals. Bearing life? There isn't one...

Dave

IMO leave it and get a better quality oil. On a couple of cars (the Stag especially) going to a half decent oil seemed to be more resistant to heat as well as giving superior oil pressure over some Unipart stuff.

An oil cooler can have a good effect on the cooling system. The Stag Owners Club once with Gaydon teamed up to see what cooling remedies worked best on the Stag. On the oil side the cooler did make a small difference to keeping the car cool, and it didn't massively slow down the rate at which the engine warmed up either .

Both my S2 and 944 Turbo had coolers .

Interesting, thanks. I didn't know that there was a bypass thermostat on the oil cooler - thank you for putting me right. I do know that there was no such a thing on the Mk1 Golf GTi, which had an external oil cooler in the oil circuit and all the oil was pushed through it all the time. The later MK2's got an oil-to-water cooler which was a superior design and I was assuming that the 944 was engineered on the same principle!


Oli.

You get a small amount of flow even with the stat "closed" but I doubt it's significant. Enough to fill empty lines & cooler though.

And later turbos do have the gearbox oil cooler .