Oil Cooler Failure 4.8is

CondorX5 · #1 12-30-2010, 02:53 PM

I know from threads on here that US-based Xes have problems with the dreaded oil separator and all sorts of damage to Valve cover gaskets and engine hydrolocks etc, so thought you'd be interested in this UK-based oil cooler failure - its fairly uncommon here, but then 4.8is Xes aren't all that common either!

My 2005 4.8is is a low mileage AUC under warranty (thank heavens) and I usually only do longish commutes in it - never less than about 30 miles, usually at least one 150 mile trip a week. Oil cap and dipstick both absolutely clean, no sign of any condensation. Car performed flawlessly despite the extreme cold in the UK recently - I've got winter tyres on it and despite temps of up to -14C, its started no problem and performance superb. Xmas Eve suddenly got a check control message after driving about for some time "CHECK ENGINE OIL LEVELS". Stopped, topped up with Edge, was close to home, message pinged up again before I reached home and it was really dark by then, so parked up. Xmas Day checked on car and discovered it had dumped a large quantity of oil

Couldn't see where it was coming from as it had mostly leaked out

Called BMW Emergency who responded quickly and efficiently - oil cooler had blown apart at one of its side seams, a really big hole......BMW Emergency arranged recovery to a main dealer and had a hire car dropped off when businesses reopened yesterday after the Xmas break - luckily there was a cooler available in the UK and it was fitted and completed this afternoon, ready for collection tomorrow.

Very very pricey repair if not under warranty and in all likelihood, I assume the failure was due to the freezing weather (I don't have a garage). The cooler and its pipework seems to be fitted in a very vulnerable place so far down and close to the front, as far as freezing temps are concerned...and UK dealers are unaware of the heated replacement vlave etc you guys in North America get.....I'm wondering if I should lag the pipework

to and from the cooler

Anyway, thought you'd be interested in hearing about similar problems surfacing this side of the pond, temperature related........fortunately for me, its all under warranty, but I do despair over the reliability of these fabulous beasts.......

rneedham1979 · #2 12-30-2010, 03:12 PM

This is interesting... I had my oil cooler split last Christmas. I thought it was a fluke but... I guess not. I walked out to start the car, I was walking back towards the house and my wife said "what is that coming from the car" I figured she was taking about water melting off, I turned around and it was oil. It pumped about 3 qts on the ground before I shut if off. Luckily, I shut it off before it was too late. BMW covered it but I often wonder if there was any internal wear due to the low oil level.

I have a few pics somewhere... If I can find them, I will post them up...

CondorX5 · #3 12-30-2010, 04:08 PM

What model X5 do you have? BMW confirmed no engine damage with mine - the V8 engine is actually relatively tolerant to low oil pressure - provided it hasn't been run with the red oil light on, ie absolutely dry, there shouldn't be any damage. The Handbook states it is driveable for a few miles after the CHECK ENGINE OIL LEVEL message, but not after the red oilcan light appears - that is virtually nil oil present and you must stop immediately to avoid serious engine damage.

rneedham1979 · #4 12-30-2010, 04:14 PM

4.8is. I wasn't driving so... I'm sure there wasn't any issue, just a bunch on oil dumped on the ground

CondorX5 · #5 01-01-2011, 06:28 PM

Here is a pic of the replacement oil cooler in place....BMW Emergency and the dealer were very efficient and I had the X back within 2 days, ready to welcome in the New Year

Is the oil cooler problem the same problem that you have in North America? If so, its strange that I don't do short trips and there was absolutely no sign of condensation on the oil cap / dipstick.....
The original cooler blew apart at the left seam - literally!