Burning oil / grease smell

Dark Skies · 01-24-2006, 05:31 PM

Here's a weird symptom (?) that I've noticed since I've owned my replacement 944 (a little over a two months).

After a decent run (10 miles) there is a distinct odour of what smells like either burnt oil or grease from the engine area when standing at the front of the car. I'm wondering what could be causing it. I had the local Porsche specialist keep an eye out for anything unusual when he replaced my cam and balance belts and he saw nothing amiss.

The car has only done 65,000 miles and is the most oil tight example I've seen. No leaks anywhere - undertray is pristine.

I don't have power assisted steering so there's nothing that could be dribbling on the exhaust.

The wheel bearings are well greased (just checked prior to readjustment) so they're not overheating.

Brake fluid reservoir is drip free so, again, not dripping on the exhaust.

There is no oil in the exhaust (oil level never seems to change) so it can't be exhaust fumes.

There is only one external belt (alternator) and that's good and tight (within spec) - so I'm not mistaking burning rubber for frying oil.

The engine is clean so it's not oil burning off hot casings.

I'm at a loss to think what else it could be.

Anyone got any other areas they think I might check?

Anyone had the same symptoms?

Cheers in advance.

nynor · 01-24-2006, 05:52 PM

you are smelling the greasy rubbish they put on engines when they detail them to make the rubber/plastic bits shiney. it is burning off when it gets hot.

fast924S · fast924S's Garage

Also inspect the exhaust system it may have got a plastic bag stuck on it that is buring/melting

Dark Skies · 01-25-2006, 12:28 PM

Well, I just checked the underside of the car and there's nothing caught on the exhaust - although, annoyingly, I did notice the front silencer looks like it'll need replacing in a few thousand miles - quite corroded externally (not leaking though).

Looking through the extensive paperwork it doesn't look like it's seen a workshop that'd bother with detailing the engine bay rubber / plastic either. Not for at least twenty thousand miles at any rate.

Good guesses though.

nynor · 01-25-2006, 12:32 PM

is there oil spilled onto the head from the filler tube?

Slam · 01-25-2006, 01:29 PM

Are you sure the smell is coming from the engine bay? I'd check my tranny and CVs after a long run. Mine (the CVs) gave off a distinct odor of hot grease, basically telling me to change them or they'd get even with me.

Dark Skies · 01-25-2006, 02:52 PM

I use a funnel to put the oil in so I don't get oil on the drive - so no to spillage on the casing.

Quote:

Originally posted by Slam
Are you sure the smell is coming from the engine bay? I'd check my tranny and CVs after a long run. Mine (the CVs) gave off a distinct odor of hot grease, basically telling me to change them or they'd get even with me.

I'm changing the tranny oil this weekend so I'll check the colour when it's out. Pretty sure it's not coming from the rear though - I had a good sniff around. I replaced the bearings recently and wondered maybe if I'd got a little grease on the brake discs by accident. No odour at the back as I could smell.

Doesn't have the same smell as burning clutch either - and no symptoms - appears pretty sweet.

nynor · 01-25-2006, 05:01 PM

YOU didn't spill any, but did the previous owner?

Razorback1980 · Razorback1980's Garage

If you got grease on the rotors, you would know it. Grease on your brake pads will make them grab. I don't think that's it, but I'm not sure what it is either. May be the emissions system. Are the hoses going to the emissions devices okay? No cracks or anything like that.

Slam · 01-25-2006, 08:55 PM

Okay...

How about back of the cam housing leaking onto the exhaust manifold? It's close enough to the hot exhaust that the oil would burn and you wouldn't see the leak.

Razorback1980 · Razorback1980's Garage

My 86 did that. When I would stop, it would fill the inside of the car with smoke. Mine wasn't a small leak though..when it started leaking, it leaked a lot. If it was just a drip, that might be it. If that is it, better get it fixed quick as it drips right on the headers and could easily turn into a car fire.

Dark Skies · 01-26-2006, 10:52 AM

I panicked and ran out to look at this latest theory. Happily the engine is uber oil-tight - not so much as a smear of oil anywhere. The back of the engine is dry and clean. The engine looks as if it might have been steam cleaned it's that muck free.

I'm really wracking my brains here. I get the occasional whiff of hot oil if I have the heater on full blast - no smoke in the car or in the engine bay though.

Razorback1980 · Razorback1980's Garage

Didn't mean to scare ya, but a friend of mine kept driving his 944 after his started leaking and it turned the paint from red to really black. I'm sorry but I'm at a loss for anything else at the moment, but I'll check into mine some more this weekend and see if I can think of anything else.

Dark Skies · 01-26-2006, 12:45 PM

Quote:

Originally posted by Razorback1980
Didn't mean to scare ya, but a friend of mine kept driving his 944 after his started leaking and it turned the paint from red to really black. I'm sorry but I'm at a loss for anything else at the moment, but I'll check into mine some more this weekend and see if I can think of anything else.

Well, on the plus side thus far none of the more serious possibilities have borne fruit. I was quite concerned when I thought it might be some kind of fraying belt thing. And then pretty annoyed when the technician told me my belts probably had another ten thousand miles left in them. Fortunately the pulleys needed slight attention and that kind of made up for having to shell out for the front end coming off.