Results of poor PCV? (with pics)

[supercity]

I looked at a 6Cyl BMW X5 today that was burning through a lot of oil. It has apparently been serviced well but looking under the oil cap it looked like sludge city. I took the rocker cover off and it was crusted with black carbon like crud.

However the valve gear and cyl head was not too bad.

Arouud the filler cap and main PCV vent is where the crud is. The main PCV vent is by this cam gear.

The PCV valve itself is enormous and under the inlet manifold. It appeared to have a significant amount of oil leaking from it and the pipes leading to the PCV were full of the same crud. I cleaned the valve cover, replaced the PCV and all the pipes and filled it with Synpower 0w40. Do you think the black crud is a result of poor PCV and would this lead to the oil consumption? I hope so, It was a full days work!

 

[eljefino]

It happens. I believe it's the cooler compsosite cover that causes condensation and muck. I wouldn't sweat it.

 

[ARB1977]

It's possible. At least you found it when you did.

 

[Phishin]

It's just condensation of the more volatile components of motor oil. Parts of the oil vaporize due to heat, those vapors rise to the top of the engine and condense most rapidly at the coolest area they can find. The black crusty carbon crud is the result of actual oil, volatile oil vapors, and water condensing together on the underside of your valve cover. Fairly typical, actually.

There is some light/moderate varnish on the valve train, but that won't hurt a thing.

The crusty black carbon stuff you are seeing isn't stuck to anything that can cause damage either. I think it was a good idea you cleaned it all up there. I would have. I couldn't have buttoned her back up without a proper cleaning first.

Did you remove the crusty stuff from the last picture?

You never indicated how fast this engine is consuming oil. However, if the PCV and it's plumbing was plugged with this carbon mess, this would accelerate the accumulation of this crud under your valve cover. Absolutely. The PCV system should be sucking all kind of vapors (oil and water vapors) out of the top of your engine. If your was plugged, those vapors aren't going anywhere....giving them plenty of opportunity to create this type of mess.

I suspect, if you cleaned up the valve train area, and got the PCV fully operational, everything should be fine and you shouldn't see this mess again.

 

[JHZR2]

Good pics! The varnish doesn't bother me much but the black sludgy deposits do. It seems to me that it is "just" an artifact of condensation or something like that, not all out sludge, but one can see how that might occur if certain flow paths are impeded.

 

[wag123]

If the PCV valve or plumbing gets plugged up, the engine will burn oil like crazy. Ask me how I know.

 

[jrustles]

That looks par for the course on contemporary BMW engines, in my experience anyway. They seem like they would benefit greatly from low NOACK oils

 

[Merkava_4]

How long has your oil change interval been? What kind of oil has your BMW been serviced with?

 

[Lubener]

The sludge and plugged PCV are all the result of poor oil changing maintenance.

 

[antonmnster]

Looks like every BMW I've seen that's been serviced every 15k. But they still run forever, so I wouldn't worry.

 

[Raybo]

Looks like life spent on dyno oil and poor oci.

Crazy how people can own a very expensive and high performance car and treat it like [censored].

 

[Merkava_4]

Originally Posted By: Raybo

Crazy how people can own a very expensive and high performance car and treat it like [censored].


That's because the rich people who buy those cars are mechanically inept.

 

[OVERKILL]

Originally Posted By: Raybo
Looks like life spent on dyno oil and poor oci.

Crazy how people can own a very expensive and high performance car and treat it like [censored].


Probably not, most likely just BMW synthetic 5w-30 at the OLM interval.

If you think this one is bad you should see what we found under the valve cover of my wife's 328i.

 

[tiger862]

Looks like that cam tower has overheated. Black sludge for cams in picture is an example of this. Check oil pressure to make sure it is sufficient especially after it gets hot. I would have to check the cam tower and cam for wear if pressure is low. Looks like if that is the case then you will need a head.

 

[OVERKILL]

Originally Posted By: tiger862
Looks like that cam tower has overheated. Black sludge for cams in picture is an example of this. Check oil pressure to make sure it is sufficient especially after it gets hot. I would have to check the cam tower and cam for wear if pressure is low. Looks like if that is the case then you will need a head.


If you are talking about the VANOS unit with the heavy varnish/sludge on it, that's all it is. It is directly below the breather vent on the valve cover and accumulation on that part is common. I don't see any signs of overheat in the OP's pictures.

 

[Merkava_4]

Originally Posted By: OVERKILL

Probably not, most likely just BMW synthetic 5w-30 at the OLM interval.


It's been said on the internet that it's impossible to get varnish stains with synthetic oil, your thoughts?

 

[OVERKILL]

Originally Posted By: Merkava_4
Originally Posted By: OVERKILL

Probably not, most likely just BMW synthetic 5w-30 at the OLM interval.


It's been said on the internet that it's impossible to get varnish stains with synthetic oil, your thoughts?


That whoever said that is out to lunch, LOL!

My sister's car, with complete dealer maintenance as per the OLM on BMW 5w-30 had slight varnish on the head.

 

[Merkava_4]

Originally Posted By: OVERKILL
Originally Posted By: Merkava_4
Originally Posted By: OVERKILL

Probably not, most likely just BMW synthetic 5w-30 at the OLM interval.


It's been said on the internet that it's impossible to get varnish stains with synthetic oil, your thoughts?


That whoever said that is out to lunch, LOL!

My sister's car, with complete dealer maintenance as per the OLM on BMW 5w-30 had slight varnish on the head.


How many miles does it take your sister's car to go from 100% to 0% on the OLM, do you know?

 

[OVERKILL]

Originally Posted By: Merkava_4
Originally Posted By: OVERKILL
Originally Posted By: Merkava_4
Originally Posted By: OVERKILL

Probably not, most likely just BMW synthetic 5w-30 at the OLM interval.


It's been said on the internet that it's impossible to get varnish stains with synthetic oil, your thoughts?


That whoever said that is out to lunch, LOL!

My sister's car, with complete dealer maintenance as per the OLM on BMW 5w-30 had slight varnish on the head.


How many miles does it take your sister's car to go from 100% to 0% on the OLM, do you know?


It varies. Her OLM appears to be more aggressive than mine, as I'm up near like 25,000Km on mine at this point IIRC (I've changed the oil several times... just not reset the OLM because QP and I wanted to see just how far it would go) and it still hasn't told me to change it yet

Hers has gone as short as ~10,000Km. I think the longest we let it go was 12,000 before we just changed the oil (M1 0w-40). I wouldn't be surprised if hers allowed up to 25,000Km OCI's as well under the right conditions however, as I believe when we didn't reset the OLM it got north of 18,000Km before it triggered a request to change.

 

[Merkava_4]

Originally Posted By: OVERKILL

It varies. Her OLM appears to be more aggressive than mine, as I'm up near like 25,000Km on mine at this point IIRC (I've changed the oil several times... just not reset the OLM because QP and I wanted to see just how far it would go) and it still hasn't told me to change it yet

Hers has gone as short as ~10,000Km. I think the longest we let it go was 12,000 before we just changed the oil (M1 0w-40). I wouldn't be surprised if hers allowed up to 25,000Km OCI's as well under the right conditions however, as I believe when we didn't reset the OLM it got north of 18,000Km before it triggered a request to change.


My experience with varnish stains is that when I remove all the oil from the surface and just leave the varnish, the varnish is sticky. Brain tells me that a sticky surface wouldn't be helping the flow of oil.