Oil burning smell

F

flybobbie

Elite
 Stourbridge
Started car, it was particularly upset not to idle steady first 10 seconds (it revs up, dies and revs up again 4-5 times), gave it some throttle few times to settle, then i lowered the roof.
So as i pulled forward to move off, strong smell of burning oil.
Lifted bonnet, had a sniff exhaust side could smell burning oil.

Looked the usual places to see if it might be cracked cam cover, but nothing seen.
No oil dripping down.
Later in the day removed the engine cover, nothing untoward.
Checked the oil filter to engine seal, just the slight misting with dust stuck that has been there for years.
So bit of a mystery.
 
flybobbie said:
Started car, it was particularly upset not to idle steady first 10 seconds (it revs up, dies and revs up again 4-5 times), gave it some throttle few times to settle, then i lowered the roof.
So as i pulled forward to move off, strong smell of burning oil.
Lifted bonnet, had a sniff exhaust side could smell burning oil.

Looked the usual places to see if it might be cracked cam cover, but nothing seen.
No oil dripping down.
Later in the day removed the engine cover, nothing untoward.
Checked the oil filter to engine seal, just the slight misting with dust stuck that has been there for years.
So bit of a mystery.
Click to expand...

Are you still on the original ccv? They can cause oil burning issues as they age & gum up.
Rob
 
Yes. Original.
Has been a thought for a year or so, because the unsteady idle has been on and off during that time.
But would think smell would originate at tail pipe, not near manifold.
But ccv could be broke or a pipe leak, pushing out blow by gases (the smell) and causing unstable idle.

Might all lead to a new camshaft cover, it's at the mileage it would play up at 97k.
I will check the pipe work to the ccv.
Untitd.jpg
 
There’s two types of ccv fitted to the n52, the early type which my 3.0si used where the actual ccv was separate from the cam cover & the later type where it was integrated in the cover itself.
I think the early ones had a metal cam cover & the later ones used plastic.
Rob
 
I have seen in the past, it's the flat type on cam cover.
Save any messing i have ordered a new cam cover.
I have a minor leak in one spark plug hole so hope it seals that.
 
ccv rank case vent or pcv pressure control valve.

Valve to allow blow by gases back into inlet manifold.
Problem is if faulty can effect idle, bit like removing the oil filler cap when engine is running.
Idle on starting has been unstable for quite some time.
Hoping replacing the cam cover will cure this problem.
I could just replace the valve, but bit of a faff only to find later say a cracked cover. Do have a leaking spark plug hole seal.
Might as well change it all.
Ordered off Autodoc about 120 quid.
 
Oil might drop from the gasket (Pos 15) of the valvetronic e-motor onto the exhaust manifold on your drivers side. It's a typical fault on BMW motors.

https://www.realoem.com/bmw/en/showparts?id=LM51-EUR-05-2011-E89-BMW-Z4_30i&diagId=11_3736
 
Well think i have found the problem.

No4 spark plug hole full of oil.
Took the cover off and later i just happened to go along and push down each coil pack.
The No.4 bounced back up, tried again, wouldn't stay down.
So pulled it, it was covered in oil and plug hole full of oil.
So the seal has gone.
The oil and escaping gas must have push the coil up, wouldn't stay down.
Could be the coil still fires but spark had to jump through the oil to reach the plug, possible burning smell.

I have ordered a new cover, so hope that cures the problem.

Rough idle might be due to this, on first start voltage is 12 volts and idle wobbles.
Soon as it goes 14 volts up it settles, so the sparks might have more energy to fire plug, ignoring the effect of oil contamination.
 
RobbiZ4 said:
Oil might drop from the gasket (Pos 15) of the valvetronic e-motor onto the exhaust manifold on your drivers side. It's a typical fault on BMW motors.

https://www.realoem.com/bmw/en/showparts?id=LM51-EUR-05-2011-E89-BMW-Z4_30i&diagId=11_3736
Click to expand...

That i replaced some 6 months ago.
It's not leaking, above the coil is dry.
 
What would be a simple job if some BMW designer with his 3D computer and University education put a bit more thought into the design..
Fitted wires that cross the cam cover instead of around.
Almost impossible to releases the injector plug sockets..
Had to squeeze cover between wires.
I hoped the gaskets didn't fall off

No such luck. :cry:
 
Well this time, as i should have done to start with, used drops of superglue to hold the gaskets in place.
Because the bolts are attached to the cover, i held them all up by wrapping string around each one and tying them up, save them catching on something when squeezing it through the wire gap.

Something which did surprise me is how little oil remains stuck to the cams, they seemed dry having run on Mobil 1 oil.
But no wear or scoring.

All seems to have cured the odd idle.
 
Oil in No.4 plug hole
20221010_154736.jpg
Between the two holes a threaded hole for cam cover bolt.
Not sure if when the bolt is tightened it bottoms out to maintain tension.
All the seals had gone hard.
Main problem is getting the cover under the wiring.
20221010_154731.jpg
Lot less hassle if wiring had been made to fit around the cam cover.
 
I know, but the design is a right pain. I tried different way to lever but didn't want to break them.
With the cam cover on you can't get near them.
And not connected individually, unless they separate having removed the plastic conduit.
Would be simpler if wires were routed around the back of the cam cover.
 
flybobbie said:
I know, but the design is a right pain. I tried different way to lever but didn't want to break them.
With the cam cover on you can't get near them.
And not connected individually, unless they separate having removed the plastic conduit.
Would be simpler if wires were routed around the back of the cam cover.
Click to expand...
Yes, I know that hassle too. 8)
 
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