2003. 2.5 M54B25 oil problem again

[zriha]

So, this is the engine:

WhatsApp Image 2021-04-22 at 10.04.53.jpeg (200.94 KiB) Viewed 895 times

I now have about 201.000 km. Mechanic say everything looks great on the valves and engine, no oil leaks at all.

It has a valve gasket change at 199.900 km and new oil. On the recommendation, I put Liqui Moly oil additive with the new oil - 5W40 Shell Helix Ultra.

So what's going on, I just drove around 1.200 km on the highway (Zagreb to Dubrovnik - King's landing and back), 130-140 km/h speed, without any stop, I even manage good fuel consumption of 7.6 liter / 100 km.

I noticed speckles of oil on the rear bumper. And about 600-700 ml of oil missing in the engine (I needed to fill in).
Those speckles of oil came up after the car went to full detailing (engine wash, everything), so is it something from that or?

One noticeable thing - the car doesn't produce any smoke on the exhaust -on cold and warm start, on regular and high speeds.

Is it maybe time to do the VANOS reparation with repair kit https://www.ebay.de/itm/Premium-Reparat ... 2663021249 ?

Thank you!

[enuff_zed]

Hi, this sounds very similar to the issue 'Rachel!!!!' is having. Search 'sooty exhaust'.
Although hers is a later 2.5si (N52).
At the moment the thinking is either blocked CCV system or possibly dried/hardened valve stem seals.

[patriot66]

Sounds like an oil leak somewhere blowing back under the car at high speed and sticking to the rear of the car. Maybe blocked CCV, leaking oil filter housing gasket, oil pan gasket etc...time to get out and get under and investigate. Fingers crossed it's just a gasket

[zriha]

Thank you gents for the help.

This is the valve cover that I replaced, it is full package:

noname.jpg (24.6 KiB) Viewed 852 times

locked CCV system or possibly dried/hardened valve stem seals.

What are the other symptoms? The car runs great, I don't feel any power shortage or anything like that.

[enuff_zed]

What are the other symptoms? The car runs great, I don't feel any power shortage or anything like that.

There appear to be no other symptoms at all, just black spots appearing over the back of the car, though in Rachel's case they are concentrated around the exhaust pipe and above it. She says hers hasn't used much oil, but it only does short journeys.
The theory is that either excess crank case pressure is pushing oil past the valve stem seals or that the seals have hardened with age and aren't sealing properly.
Or a combination of both.

[Mike6]

Just a thought,
When changing the oil you have to drop down the flap on the underbody tray to access the sump plug. Even being very careful the surge of oil exiting the sump means that some ends up on the undertray which can then blow back towards rear of car. I know this doesnt explain your oil loss but is it possible that car was just filled up and then not checked again on the dipstick after starting for a few moments. This can make a fair difference on the dipstick and its not unknown for mechanics to do this.
Before getting too involved with leaks etc just top up and try again. Otherwise you may need to drop underskirt and start delving.

[zriha]

There appear to be no other symptoms at all, just black spots appearing over the back of the car, though in Rachel's case they are concentrated around the exhaust pipe and above it. She says hers hasn't used much oil, but it only does short journeys.
The theory is that either excess crank case pressure is pushing oil past the valve stem seals or that the seals have hardened with age and aren't sealing properly.
Or a combination of both.

Well, thank you, and now out of the ordinary thought, what I did, well major thing - changed the intake air filter, from a regular one to the Pipercorss air filter that gives more air. Maybe I messed things up?

Valve steam seals? How can I change them?

Before getting too involved with leaks etc just top up and try again. Otherwise you may need to drop underskirt and start delving.

Thanks Mike, I will try that!

[Mike6]

Dont think you will have messed up changing air filter to a pipercross one and assume you didnt alter air intake arrangements ie just changed the filter. Topping up and trying car again will give you a baseline on the dipstick so trying that before looking at any other explanation.

[patriot66]

I can't understand why you don't start with a visual inspection of the engine, engine bay, under the engine, gearbox etc. If you find a leak then there's your problem answered, if you don't find a leak then it is probably something more serious. If it has used 700ml of oil over 1200km(750miles) I would be worried

[zriha]

I can't understand why you don't start with a visual inspection of the engine, engine bay, under the engine, gearbox etc.

I started with that, and as I said, the car was before that trip at a mechanic who changed the valve cover gasket, he inspected the engine and I asked about the leaks, and he said everything is fine.

When I am reconstructing the steps, this thing happened when I:
a. returned the car from detailing, where they cleaned the engine and everything - 2 days work
b. removed the OEM air filter and fitted the Pipercross filter

Regarding the second thing, yesterday I bought OEM filter and fitted it back to the car. Pipercross filter wasn't fitted good, so I reckon that some of the air come to the MAF thru the not good fitted airbox.

Regarding oil consumption, as I said, it is definitely time for VANOS reparation with a repair kit, because that is the first symptom I read and asked among other owners of this engine. Common thing is that they start to "drink" oil, and when I put milage on the car, it is a logical thing.

[patriot66]

I started with that, and as I said, the car was before that trip at a mechanic who changed the valve cover gasket, he inspected the engine and I asked about the leaks, and he said everything is fine

I appreciate a mechanic has changed the gasket and inspected the engine but if it was my car then I would physically want to investigate for any leaks myself.

Regarding oil consumption, as I said, it is definitely time for VANOS reparation with a repair kit, because that is the first symptom I read and asked among other owners of this engine. Common thing is that they start to "drink" oil, and when I put milage on the car, it is a logical thing

Not sure about this. I am an 'owner of this engine' too. I have an M54 2.5i exactly the same as you. Mine has done 90,000miles/145,000km and I rebuilt my VANOS myself last summer. It never used a drop of oil before that and it's never used a drop of oil since. I think you're barking up the wrong tree here.
You originally said you noticed 'speckles' of oil on your back bumper and that it makes absolutely no smoke from the exhaust at any time. This would make me believe your engine isn't burning any oil, which logically would also make me believe you must have a leak...somewhere.
Have you checked for certain that the new cam cover gasket isn't leaking...run your fingers around the gasket when the engine is cool. It may be a poor quality item, seated incorrectly, not torqued down correctly or in the correct criss-cross pattern. Did the mechanic apply silicone RTV sealant on the corners of the 'quadrants' on the gasket ? Did he fit the spark plug hole gaskets correctly ? If he didn't then your spark plug tubes could be full of oil, possibly 600-700ml or more.
Also, having changed every single engine gasket on my Z4 over the last few years and knowing how hard and brittle or perished they become with age, then I would be amazed if your oil filter housing gasket isn't leaking down the block. Mine did and at only 65,000miles/105,000km

[Smartbear]

I started with that, and as I said, the car was before that trip at a mechanic who changed the valve cover gasket, he inspected the engine and I asked about the leaks, and he said everything is fine

I appreciate a mechanic has changed the gasket and inspected the engine but if it was my car then I would physically want to investigate for any leaks myself.

Regarding oil consumption, as I said, it is definitely time for VANOS reparation with a repair kit, because that is the first symptom I read and asked among other owners of this engine. Common thing is that they start to "drink" oil, and when I put milage on the car, it is a logical thing

Not sure about this. I am an 'owner of this engine' too. I have an M54 2.5i exactly the same as you. Mine has done 90,000miles/145,000km and I rebuilt my VANOS myself last summer. It never used a drop of oil before that and it's never used a drop of oil since. I think you're barking up the wrong tree here.
You originally said you noticed 'speckles' of oil on your back bumper and that it makes absolutely no smoke from the exhaust at any time. This would make me believe your engine isn't burning any oil, which logically would also make me believe you must have a leak...somewhere.
Have you checked for certain that the new cam cover gasket isn't leaking...run your fingers around the gasket when the engine is cool. It may be a poor quality item, seated incorrectly, not torqued down correctly or in the correct criss-cross pattern. Did the mechanic apply silicone RTV sealant on the corners of the 'quadrants' on the gasket ? Did he fit the spark plug hole gaskets correctly ? If he didn't then your spark plug tubes could be full of oil, possibly 600-700ml or more.
Also, having changed every single engine gasket on my Z4 over the last few years and knowing how hard and brittle or perished they become with age, then I would be amazed if your oil filter housing gasket isn't leaking down the block. Mine did and at only 65,000miles/105,000km

Agree with you that the vanos won’t cause oil burning issues (how could it?) but disagree that oil burning is accompanied by a Smokey exhaust, a lot of this is masked by the catalyst in the exhaust & the way the rear silencer isn’t “direct” in its routing-it’s convoluted and filled with wadding that absorbs any evidence of a dirty running engine. What you’re left with is a speckled bumper coated with oily carbon.
Rob

[patriot66]

I started with that, and as I said, the car was before that trip at a mechanic who changed the valve cover gasket, he inspected the engine and I asked about the leaks, and he said everything is fine

I appreciate a mechanic has changed the gasket and inspected the engine but if it was my car then I would physically want to investigate for any leaks myself.

Regarding oil consumption, as I said, it is definitely time for VANOS reparation with a repair kit, because that is the first symptom I read and asked among other owners of this engine. Common thing is that they start to "drink" oil, and when I put milage on the car, it is a logical thing

Not sure about this. I am an 'owner of this engine' too. I have an M54 2.5i exactly the same as you. Mine has done 90,000miles/145,000km and I rebuilt my VANOS myself last summer. It never used a drop of oil before that and it's never used a drop of oil since. I think you're barking up the wrong tree here.
You originally said you noticed 'speckles' of oil on your back bumper and that it makes absolutely no smoke from the exhaust at any time. This would make me believe your engine isn't burning any oil, which logically would also make me believe you must have a leak...somewhere.
Have you checked for certain that the new cam cover gasket isn't leaking...run your fingers around the gasket when the engine is cool. It may be a poor quality item, seated incorrectly, not torqued down correctly or in the correct criss-cross pattern. Did the mechanic apply silicone RTV sealant on the corners of the 'quadrants' on the gasket ? Did he fit the spark plug hole gaskets correctly ? If he didn't then your spark plug tubes could be full of oil, possibly 600-700ml or more.
Also, having changed every single engine gasket on my Z4 over the last few years and knowing how hard and brittle or perished they become with age, then I would be amazed if your oil filter housing gasket isn't leaking down the block. Mine did and at only 65,000miles/105,000km

Agree with you that the vanos won’t cause oil burning issues (how could it?) but disagree that oil burning is accompanied by a Smokey exhaust, a lot of this is masked by the catalyst in the exhaust & the way the rear silencer isn’t “direct” in its routing-it’s convoluted and filled with wadding that absorbs any evidence of a dirty running engine. What you’re left with is a speckled bumper coated with oily carbon.
Rob

Maybe, but why not first eliminate the question of any oil leaks by a thorough inspection of the engine, gearbox, differential and underside ? It's not difficult, would only take a few minutes and would surely determine whether the problem is external or internal

[zriha]

Thanks gents for suggestions. Well, the front right shock absorber leaked oil, and I change them both a week ago. The oil was on the front right fork and everywhere, but it is clean now.

The whole thing started when the car was on detailing and they washed the engine and protected with something.

Then I changed the air filter, and I noticed that the exhaust pipes were black, so now I have OEM, and maybe (looking at the Rachel post) the MAF was reading wrong data because of the Pipercross filter.

What I did:
checked the car, no leaks

What I will do, is a simple old school test, start the car, put white papers at the back of the exhaust pipes, let it warm up, and then rev it. If it is spitting oil, then I know there is a problem.

Researching about these engines, a lot of them has oil drinking problems, there are a lot of possible solutions, Vanos is one of them.

Weekend is here, I will take my time also I will clean exhaust pipes as much as I can.

[patriot66]

Sounds like a plan However, as a matter of improving the driving experience by improving lost engine torque then yes I agree with rebuilding your VANOS, but having done it myself I am almost 100% certain that oil consumption will not be affected at all