Oil burn and idle issue....

[dva99999]

Hi all, (accidentally put this on wrong forum page)
For a while I've had an issue where when parking the car after a hard drive I've smelt and noticed a little smoke coming from the passenger side of the engine. It's not a lot and there is still plenty of oil when I check the car. It's a late 98 2.8
Only recently I've now noticed that when idling from cold it seems like the engine will cut out, the rev counter dips between around 600-900rpm. Once the engine is warm the problem goes away.

At first I thought it was 2 different issues neither one of them serious enough, as I was neither losing oil (much) nor was the car stalling. But I have read that both issues may be caused by one particular problem, that being a crack or perished seal in the rocker cover. I don't have anything with me to do a test for oil pressure but can anyone confirm this?
The car does not seem down on power but I darent drive it too hard in case I cause further damage.

There is a really good article in Pelican Parts on how to change the seals on the rocker cover, and I have done a similar job on an old MG.

Cheers
D

 

[colb]

A leaking rocker cover seal will have no effect on the engines oil pressure it will just leak. Change the seal but give the mating surfaces a good clean before refitting. Throttle body may need a clean the butterfly in there may be sticking giving you the cold start issue. Might be worthwhile cleaning the idle control valve as well whilst your at it as that could also be a cause.

 

[littlefeller]

air leaks in rocker covers do cause idle issues, the same as removing the oil filler cap on top while the engine is running, though it would have to be a fair sized leak, sounds reasonable to me though.

 

[Dino D]

Had the seals arrive today from Sopers for my garage to do this exact job.
I decided to get the o rings for the 12 bolts, oil cap gasket and the 2 little o rings that should be renewed when doing the oil filter (for a 2.8 single vanos):

 

[dva99999]

I'll start with those....time to get dirty again!!

 

[NZ00Z3]

It's your CCV (crank case Ventilation), you have a broken hose. Most likely ones are from the valve cover to the separator or separator to dip stick tube.

This matches you symptoms:
- Oil smell on passengers (inlet manifold) side from the fumes coming out of the broken hose. The leaking valve cover gasket typically drips oil on the drivers (exhaust) side and it gets burnt on the hot exhaust manifold, so it is less likely from your symptoms.

- Rough running when cold as you effectively have un-metered air getting into the inlet manifold through the broken hose. Take the oil filler cap off with a cold running engine and it will stumble and splutter just the same as when the CCV hoses are broken. When the engine is hot, it switched into closed loop mixture control and the DME sees the lean mixture via the O2 sensors and pumps more fuel in to balance it, hence no stumble when the engine is hot.

Hope this helps

 

[dva99999]

Hi there, going on from the above. Assuming it is a CCV hose, the problem I'm having is sourcing the parts. I've had a look on Pelican parts for a guide on how to do this and it suggests replacing other parts as well as they could have perished with time. I've taken the parts from the realoem site but when I put in those parts online (GSF) they list different part numbers or they don't stock them all.
BMW are charging £180.00 for them all but I'm unsure now that they are the rights ones.
Crankcase breather valve (11617501566) £38.78
Crankcase breather drain hose (11157532649) £14.89
Crankcase breather pipes (pipe to valve cover 11611440317 £25.67 crankcase breather,
pipes to intake manifold (11611432559 £17.14 & 11157520035 £25.67
Oil drain hose to dipstick tube (11431437140 £55.05) ( top o ring 11431717666 £0.55X 2, bottom o ring 11431740045 £1.72)

I have a late 98 2.8 so I'm assuming it's a dual VANOS.
If anyone has done this on theirs would you still have a receipt with the part numbers so I can check?

Thanks
D

 

[Poprin]

I had similar issues on my 3.0. I've added a photo of the parts I ordered from BMW and I probably could have got them cheaper elsewhere but I just wanted it done and done right because my car was drinking oil at an alarming rate and I didn't want to cause potentially more expensive problems! My car had power delivery issues when it was warm and stank of oil if you put your foot down with the roof open, as it was leaking into the engine bay and burning off the manifold. Also was puffing white smoke out the exhaust under heavy acceleration. So I have had the rocker cover gasket replaced and all hoses and CCV valve done and it is completely sorted. Engine is sweet as a nut and uses no oil at all and it's done 124k.

 

[dva99999]

I had similar issues on my 3.0. I've added a photo of the parts I ordered from BMW and I probably could have got them cheaper elsewhere but I just wanted it done and done right because my car was drinking oil at an alarming rate and I didn't want to cause potentially more expensive problems! My car had power delivery issues when it was warm and stank of oil if you put your foot down with the roof open, as it was leaking into the engine bay and burning off the manifold. Also was puffing white smoke out the exhaust under heavy acceleration. So I have had the rocker cover gasket replaced and all hoses and CCV valve done and it is completely sorted. Engine is sweet as a nut and uses no oil at all and it's done 124k.

View attachment 57287

Forgot to thank you by the way. Did you do the work yourself or did you have a garage do it? If a garage what sort of costs?
I was looking at following pelican parts guide as it SEEMS straightforward enough, just time consuming.
Thanks again

 

[Poprin]

I got it done by a local mechanic at mates rates I'm afraid so my pricing would not be representative! However I can tell you the mechanic that did it was particularly good at his job and he did the whole lot, CCV and rocker cover in less than 4 hours. That was just on my driveway working out of his van as well.

 

[dva99999]

I got it done by a local mechanic at mates rates I'm afraid so my pricing would not be representative! However I can tell you the mechanic that did it was particularly good at his job and he did the whole lot, CCV and rocker cover in less than 4 hours. That was just on my driveway working out of his van as well.

Thanks for that. I do know a guy but he's very busy so it would be difficult to get it done quickly. I'll have a go and take my time.

 

[Poprin]

Yeah I'm literally waiting for the call to tell me my tracking is finished as it's away getting the proper job done, weights and all. It's been a painful process in the pursuit of cost effective repairs. My car has been either off the road or borderline un-driveable for about the past two and a bit months. Had the CCV, rocker cover done and then failed MOT on a leaky shock. So I've just had finished all the shocks, track rod ends, arb bushes, ball joints and front lower track control arms replaced. Used my mate but around his day job and that's taken some time.

Even so it's bye bye to £1150!

I'm not sure though if I would have rather spent a bit more and had it finished sooner because I've missed countless sunny days now!

 

[Cooper]

Make sure you have a small tube of the gasket sealant as you will need it for the corners of the 'humps' in the rocker cover gasket and also the place where the vanos sits snug on the head. Check the spark plug tubes to make sure no oil has slipped in there as that will certainly cause issues. If you have a bad back you can run the car up on ramps so you don't have to bend over so much. If you have never removed the fan before it may be on really tight - remember 'righty loosy' for it! To make the job easier put some WD40 on the fan nut [often] in the days leading up to the job and use the special tools to remove the fan. It is well worth the few $ to get them.

 

[NZ00Z3]

Have you had a good look at the CCV hoses and the small elbow tube going between the MAF and throttle body/idle control valve to confirm what parts is broken?

Just wondering as it easy for us to give you advise while sitting in the easy chair 10,000 miles away and we get it wrong.

 

[dva99999]

I haven't done yet, I spoke to my mechanic earlier today who pretty much said what you've said, to have a good check first before I go and buy parts I may not need. All the advice given is good because it gives me an idea of where to look, what to look for and familiarise myself with it.

 

[dva99999]

So just an update....and it's an odd one. I decided to take the Zed out for a good hard drive, taking it to its limits for about 45 minutes in the early hours. As there were very few cars it was easy.
When I got back I let it idle for a while and guess what.....no oil smell or leaks. When starting, there was no idle issues. I took my partner up to the Lakes for the weekend and it was fantastic (the A591 particularly enjoyable). Again no oil smell or leaks and as an additional bonus managed to get almost 350 miles on my full tank. Previous to this I was lucky to get 250.
It seems something was cleared, i still may change the rocker cover gasket, but it seems a hard drive was needed.

 

[Poprin]

You can get a blockage in the pipe to and from the CCV and a blockage in the valve itself. Looks like it might have cleared itself in which case you are in luck!

 

[Dino D]

350 on a tank in a 2.8?
I'm happy when I get 250!!

 

[Brian4]

Just filled our 3.0 up and the trip computer says 355 to empty but it has just been running 70ish for the last 200 miles and mid 30mpg since I reset it