oil coolers?? worth it or not?

[scottinAZ]

I was able to pick up a factory cooler off an 87 325iC today at the junkyard, and was mostly wondering if it would be worth the effort to add it to my 87 325?

It doesnt seem hard to install, but is it really worth the extra points of failure and leakage. Does anyone know how efficient the cooler is at well, cooling the oil.

Keep in mind that I live in AZ and everything that can help cool a car is normally used, so what is the boards opinions on the factory cooler, Add it, or leave it the hell alone and Sell it?

[CorvallisBMW]

I've been told that the thermostat that controls flow in to the oil cooler is set so high that it never even opens. I remember some track guys posting once that even after 20 hot laps they still weren't opening and the oil temps were fine. But maybe someone with more direct experience can chime in.

[u3b3rg33k]

After letting my car idle for a while in the summer, at about the point where the aux fan switches on, my oil cooler is too hot to touch.

I doubt bmw would've added it to production if they thought it was unnecessary, at the same time that they were simplifying things (removing the fuel pulse dampers, 2nd pump, fuel cooler, etc).

[u3b3rg33k]

I've been told that the thermostat that controls flow in to the oil cooler is set so high that it never even opens. I remember some track guys posting once that even after 20 hot laps they still weren't opening and the oil temps were fine. But maybe someone with more direct experience can chime in.

How can they tell it's not opening?

[e30rapidic]

an oil thermosat?!?!? I've rebuilt many M20's with oil coolers and never heard or seen this?!

[CorvallisBMW]

It's built in to the oil filter housing and controls the flow going in to the cooler.

[scottinAZ]

It's built in to the oil filter housing and controls the flow going in to the cooler.

Heres a pic of the innards for reference.



Also, would removing this thermostat adversely affect the efficiency of the oil filtration? does anyone know what the flow path is for the oil, IE block, filter, cooler, and then back to the block?

[McGyver]

it is sorta cool to have, but like you said, its another point to leak. the original o-rings that hold the thermostat in (the black one above) is VERY prone to drying out and leaking. you will i think you will need everything above and the lines to and from the cooler. if you dont have overheating problems i wouldnt worry about it.

[scottinAZ]

it is sorta cool to have, but like you said, its another point to leak. the original o-rings that hold the thermostat in (the black one above) is VERY prone to drying out and leaking. you will i think you will need everything above and the lines to and from the cooler. if you dont have overheating problems i wouldnt worry about it.

IF I use the cooler, it will be with all new o-rings. Aslo it needs a return line. Still on the fence about spending another 85 or so bucks on a cooler I got for under 20 bucks. I may try and replace the rubber on the factory lines with braided stainless line. but still dont know if I have any of the right size here already or not

[nando]

why would your cooler cost $85 to rebuild? the rebuild kit is $13. you need a couple more o-rings and a crush washer.

as far as the t-stat not opening on a track car - I'm willing to bet the thermostat in that car was shot. Somebody sold me a spare filter housing, it was so varnished inside that the t-stat was completely seized in an open position. it's not much of a stretch to think it could get stuck closed.

on the track you can easily see 250+f temps, n/a. I'd imagine it gets worse on hotter days/faster cars/hotter climates. I'd rather have the cooler in that situation. the likeliness of leaks is not that great..

[nando]

Heres a pic of the innards for reference.



Also, would removing this thermostat adversely affect the efficiency of the oil filtration? does anyone know what the flow path is for the oil, IE block, filter, cooler, and then back to the block?

removing the t-stat would mean it would always run through the cooler. your oil would take a lot longer to come up to temp.

[scottinAZ]

ok, first, the return line is shit (fitting is twisting in the hose, and shows signs of leakage).... 75 bucks right there. along with o-rings, 85 is conservative. Im not that concerned about oil temps, it doesnt get that cold here in AZ (almost never below freezing, and its garaged so it stays about 70 on the low side. Only reason I would remove the t-stat is if it was FUBAR, as you cant get it separately, and no way in hell would I pay for a new one at 135 (realOEM). call me a cheap ass, but im not gonna pay a fuckload to fix something the car didnt have in the first place...

[europeanplates]

This brings up the question of the oil fill level. Since generally you chekc the level of oil when the engine is not super hot when the t-state opens how much oil is lost into the lines and cooler? I would assume priming this is in the book?

Curious myabe stupid question?

Ty

[gearheadE30]

well, if the cooler was full it wouldn't matter. the angle of the hoses makes it seem like it wouldn't drain when you changed the oil, so, unless I'm misunderstanding the question, its not an issue. 'priming' would only happen if it was completely empty when you were installing one or something, and you'd only have to worry about that the first time.

[HarryPotter]

This brings up the question of the oil fill level. Since generally you chekc the level of oil when the engine is not super hot when the t-state opens how much oil is lost into the lines and cooler? I would assume priming this is in the book?

Curious myabe stupid question?

Ty

Actually I was reading my bentely earlier just for shits n giggles, and I saw nothing mentioned about that. They just say 4.2q's of oil.