BMW E39 occasional smell of oil

I've got an early BMW E39 528. Mileage about 100,000 and runs very well. Oil consumption negligible.

Every now and again I get a strong smell of burnt oil inside the car. It also sometimes puffs out a large burst of blue smoke from the exhaust on a cold start - usually after a fast run.

I'm thinking the engine breather system could do with a clean or replacement. As far as I know it's never been touched. The only engine work done was replacement of the cam cover gasket some time ago. It doesn't appear to be leaking any oil.

Anyone done this and got some tips? I assume there's some sort of oil separator valve or whatever - but can't actually see where it is.

Reply to
Dave Plowman (News)
Loading thread data ...

So ~20yo?

Hardened valve stem seals?

Reply to
Adrian

Getting on that way.

I'd expect those to cause problems all of the time. This seems to me like only occasionally, oil is getting into the combustion chamber and burning. Which is why I suspect the breather system. On my other car the entire breather system is on the top of the engine and easy to get at. On the E39 I can't really see any of it.

Reply to
Dave Plowman (News)

Dunno about the M52, but have done a later M54 530i. On those the CCV system is all under the inlet manifold, the main lump of it being a kidney shaped thing that gives trouble a damn site sooner than yours! Apparently there are people who do it with the inlet in situ, but it's best approached by removing it.

Have you discovered RealOEM.com? All the BMW parts diagrams with lots of positional detail about components.

Reply to
Scott M

On the overrun's most likely. If they're not that bad, then quite possibly when you've been giving it some berries. Can't imagine it gets used that hard round where you are.

Reply to
Adrian

valve stem seals would put oil out of the exhaust, it is unlikely the op would smell that in the cabin, and the cat should clean that up in any case. A leak that sometimes gets to the exhaust would be the first thing to hunt for.

Reply to
Mrcheerful

I mean of course that the leak drips on to the hot exhaust pipe. Parking the car after a good run over a large clean bit of cardboard can be a useful way to spot some leaks. (remove undershield first)

Reply to
Mrcheerful

Yes - I'd guessed that's where it was. Think I'll bite the bullet and remove the inlet manifold - far rather work from the top of the engine.

Do my symptoms sort of match up?

Reply to
Dave Plowman (News)

Possibly...

The M54 is a natural oil guzzler (1 ltr/2000 miles is very good) and this then goes up when the CCV system goes t*ts up. The test there is to remove the oil filler with it running to check the vacuum present in the rocker cover. There's a spec somewhere that says it should be a few mBar, but when it's buggered, removing the oil filler cap reveals a level of suction Dyson would kill for. You can lose clothing to it.

Thinking about it, I suppose a dodgy CCV system causes oil to be injested and burnt at a continuous rate whereas, to get your puff of blue smoke, it's a build up that's collected and then burns in one lump when you start. Which does sound a bit valve stem oil seal-y, doesn't it?

Then, having written all that, I did a bit of idle googling. I don't recall the oil smell being associated with CCVs on M54s, but I found a few hits to say it was on the M52. I also came up with:

  • M52 & M52TU have different CCV systems, the TU more like the M54.

  • a couple of references to the actual valve cover leaking, rather than the gasket.

I suppose there's no harm in replacing the CCV system. The pipework I did was horribly brittle and, while ok in place, shattered when I attempted to disconnect it.

And apologies for the M54 heaviness, the forum I frequent only seems to have owners with them and I've only ever played with my pal's 530i and the M50 I used to own. Seem to have missed out on the M52 somewhere!

Reply to
Scott M

Right - my brother has a 330t with the M54 and it certainly uses more oil than my M52. Rather more than 2000 miles/ltr. I probably top up mine twice between oil changes - usually around 12,000 miles with my driving.

I'll check that.

The puff of smoke is rare and I've only seen it after a long hard run. The smell every other day.

I did give it a good clean and examination. But that was several years ago.

I sort of suspected that. I did wonder if anyone does a complete kit?

The E39 forum I read tends to be V8 biased - and in any case being a US one, the 6 cylinder engines are different.

It's really just fear of the unknown that I'm asking. I've had so few problems with my E39, I don't really know it under the bonnet. ;-) For example, all the coolant system hoses are original. Having to change those usually gives you an idea of where things are on an engine.

Reply to
Dave Plowman (News)

So probably two separate problems then, IMO. Valve stems + "other".

Seem to be dealer only bits. BMWland.co.uk have a discount deal going with BMW Cotswold which lops a bit off plus free postage.

I didn't think there was much in it apart from the M-engines.

My 320d has just hit 205,000 and, under the bonnet, has broken a grand total of one crank pulley. The DMF is just starting to rattle and, like the clutch, is original. It'd probably have lasted even longer if I didn't do towing :-) I spend time fiddling about under the bonnet, but rarely for anything other than my own amusement - on their day BMW know exactly how to make things that last a looong time!

Reply to
Scott M

Not convinced about the valve stem seals. I've had enough old bangers with that problem to say the symptoms here ain't the same. It doesn't smoke under any running conditions - only this odd time on a cold start after a fast run. Which suggests to me oil is being trapped somewhere.

The US 6 cylinders of the day had cast iron blocks. And a 4 speed GM auto, rather than the 5 speed ZF. But don't know how much else the engines differed in design.

I'm on the fourth water pump. Some original, some aftermarket. I changed the idlers with the last pump. And third crank position sensor. Other than that and the cam cover gasket, nothing on the engine.

Reply to
Dave Plowman (News)

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.