M50 - Strange oil smell in car

[Rory525]

Hi folks,

Over the last few days noticed a strange problem.

After Ive left the car for a couple of hours, then gone back to drive it, after 5 mins of driving a sickly oil smell can be smelt in the cabin. It smells like oil fumes of some sort.

After maybe 3 or 4 mins this smell seems to go away and not occur again.

Anybody any idea what this could be? My only thought is maybe a blocked breather pipe somewhere ... only thing I can think of that releases nasty oil fumes.

Otherwise its running really nice, serviced it yesterday and its purring like a kitten again.

Any ideas appreciated.

[biondani]

Would be interested to know myself as mine does this as well.

Ian

[Rory525]

Would be interested to know myself as mine does this as well.

Ian

Maybe its only something 91 525 sports do lol

[Rory525]

Nobody else with M50 experienced this ??

No ideas what can cause it ? The smell was strong and sickly last night had to put windows down.

[632 Regal]

sorry Rory but I dont have an M-50, id guess that some oil is leaking onto the exhaust and burnung up when it gets hot. Chech it for leaks after driving it anf go from there?

[Rory525]

sorry Rory but I dont have an M-50, id guess that some oil is leaking onto the exhaust and burnung up when it gets hot. Chech it for leaks after driving it anf go from there?

Ill have a look for that Regal but I think thats ok. Its strange how it comes after 5 mins then goes away.

Does anybody know if there are breather pipes on the M50 which need cleaned out now and again ?

[Mas (UK)]

That it happens after a little drive is because the engine warms up and the leaking oil is heating up and burning off slowly or the hot oil fumes leaking out from somewhere.

First off and easiest way to diagnose the location of the problem is to follow your nose with your engine warmed up. I'd check around your valve cover, maybe the gasket is not sealing properly and leaking oil, probably onto your hot exhaust manifold. Sometimes it could be the gasket around your spark plugs, leaking oil into the spark plug chambers and getting heated from the hot plugs.

Secondly, check the crankcase ventilation 'plug' at the top of the valve cover is tight and not leaking oil. Check the rubber hoses coming off the valve cover if any have come loose or are old and damaged showing any signs of cracking. On the later M50 engines one of the smaller venting hoses goes under the intake manifold and plugs into a tiny nipple on the throttle body (I'm not sure if this is the same for your engine, hopefully the pro's here will be able to let us know). It could have come loose and basically venting the oil fumes into the engine bay and this gets sucked into the cabin. The other hose is bigger and also prone to degradation, so check it carefully.

Good luck.

Mas

[Rory525]

Thanks Mas I will check these things out.

Hoping its not some nasty oil leak thats hard to fix. Doesnt seem to use much oil really so cant be that bad.

[smcgowan]

Crankcase vent

http://www.realoem.com/bmw/showparts...84&hg=11&fg=15

Part 5 on the picture. Over time the hose dries up and cracks. The other end of the hose goes to the under the throttle body. Pain in the ass to see. I just felt may way.

The wife was complaining of gas and oil smells. After finding and replacing smells gone and oil consumpion= zero now.

[tnt525i]

same thing was happening with my M50, turned out to be the valve cover gasket, the gasket got old and started to leak just about a drop or two of oil on the exhaust side of the engine near the rear exhaust manifold, so oil would drip from the gasket and fall on the hot exhaust manifold, it would burn very quickly and smell inside the car, i pulled off the valve cover, used some silicone sealant and now no more oil leaks or oil fumes. hope that helps