$7K for valve seals, et al

[Xeno]

I know there are many threads about valve stems, but I thought my case had enough differences to warranty a new thread. If mods disagree, then please merge.

My wife loves her 2008 4.8i with less than 70K miles. She is driving me because I am recovering from fusion foot surgery. On Friday while waiting at Subway, I saw the smoke others described here. She later tells me she has seen this before.

I take the E70 to my dealer and my service adviser had left just 2 weeks earlier unknown to me. The replacement SA has the car for less than 1 hour and tells me that would charge just under $7K to replace "value seals and all associated parts". I did not check with an independent dealer that could not give a loaner and want want cash payment. This kind of mechanical work is beyond my skills.

This is no small financial hit for us at a time of other major expenses. How to I determine if putting out the $7K will give us another 2-3 years? I see other threads here but apparently most of those were under warranty so I wonder if others then sold as soon as their warranty expired.

Kelley Blue Book value for our 2008 X5 is $7,288-8,929. Am I better off to try and trade now and cut my loses even though everything else seems okay? My wife does not need an SUV and we do not want an old used BMW.

[X5 MAN]

My wife loves her 2018 4.8i with less than 70K miles

How do you put on so many miles in one year ?

[Xeno]

Originally Posted by X5 MAN

My wife loves her 2018 4.8i with less than 70K miles

How do you put on so many miles in one year ?

Thanks for finding the typo. No contacts just yet this morning as I need another pain med for this surgery foot.

[Sophisticated Redneck]

I seriously doubt you need valve seals. No engine should need valve seals until 200k+ IMHO. Its most likely a clogged PCV valve or leak in the PCV system. Easy way to check is pop the hood while the engine is running and pull off the oil filter cap. If there is no resistance (you can't feel any vacuum in the engine pulling on the cap as you remove it) then you know you have a problem. Hook up a vacuum if want to be fancy, should have at least -10-15 psi at idle in the crankcase. BMW is known for having weak as hell PCV systems that clog easily.

You see without any Crankcase Vacuum, when things like valve seals get a little wear in them after 50K+ miles, the oil is going to shoot right down the valve...At Idle most engines will pull negative 18psi or more..think about that, -18psi vacuum flowing right around the intake valve and with a faulty PCV system you will have no Vacuum or worse even a slight positive pressure so its no wonder oil will be sucked right into the combustion chamber.

I have a 50i with the N63, replaced all the entire PCV system with new, still had what started as a light smoke at stop light turn into a damn fogging system....got so bad people would stop me and tell me something is wrong with my car.... on the N63 engine the PCV system is a f*cking JOKE. I made my own with a proper amount of crankcase Vacuum and no more smoke at Idle and I have 130,000 miles on her.

I dont know to much about the 4.8i but from what I can tell its PCV system looks much easier to replace and cheaper too. I would start there if you dont have any crankcase vacuum. If its crap design like the N63 and you still dont have any real vacuum after replacing then you can make your own like I did. Since your engine is non-turbo it would cost you about 50 dollars for a few hoses, catch can and cheap generic PCV valve from autozone.

Pic of one side of my setup below, for a non-turbo engine its alot easier as you dont need a two stage PCV system.

[Xeno]

I think the dealer determination was in part influenced by codes because each time I drove the 2008, an error message came up about oil getting close to the minimum. I would then look at the dipstick and it always showed full as I even added a little oil when the warning messages showed up maybe 2+ months ago.

I am asking the dealer SA to put in writing what he told me in person as I was in shock when I saw the $7K charge. I think he said that during the last oil change - which was done by the dealer - that something about the coolant cover was not correct. They made this change for no charge and said that the leak I saw that generated the smoke was coolant.

My mobility is limited due to the foot surgery, but I will try to find a way to do the oil filer cap test you suggest. However, the videos I saw just now make me think I would do more damage than good with even such a simple assignment.

Thank you for giving me a sense of direction.

[Sophisticated Redneck]

Originally Posted by Xeno

I think the dealer determination was in part influenced by codes because each time I drove the 2008, an error message came up about oil getting close to the minimum. I would then look at the dipstick and it always showed full as I even added a little oil when the warning messages showed up maybe 2+ months ago.

I am asking the dealer SA to put in writing what he told me in person as I was in shock when I saw the $7K charge. I think he said that during the last oil change - which was done by the dealer - that something about the coolant cover was not correct. They made this change for no charge and said that the leak I saw that generated the smoke was coolant.

My mobility is limited due to the foot surgery, but I will try to find a way to do the oil filer cap test you suggest. However, the videos I saw just now make me think I would do more damage than good with even such a simple assignment.

Thank you for giving me a sense of direction.

Usually the only way coolant can cause smoke is if you have a cracked head and coolant is leaking direct into the combustion chamber. If this were the case you normally would see smoke all the time and your oil on your dipstick will be a milky color. Excessive oil in the combustion chamber can look just like a coolant as our smoke looks nearly the same. When mine started smoking so bad I thought for sure it was cracked head coolant leak but the oil was clean and the PCV system I made fixed it...I was shocked what a difference it made. When you are healed up check out your PCV system, I bet that's your problem with only 70k on it.

[Xeno]

Being naive in things mechanical, all I could tell the dealer was that when I was looking at the dipstick that roughly the 10 am mark I could see some liquid leaking. I was told it was not oil, but perhaps I misunderstood that it could have been coolant.

The smoke was light gray and not thick. The oil is not discolored that I remember. This dealer has done two major oil leak jobs in the last two years so that kind of issue still has some kind of warranty.

[Xeno]

My wife just took me for a drive in the 2008 and I noticed that the coolant icon came on. I do not understand why BMW did not top that off when they had it briefly last Friday.

So can I top the coolant off and as long as all the status readings are clear (green) search for a solution to the mechanical issue at hand?

[Poppyboy]

If the car is smoking, not burning oil and your coolant is low, head gasket?

[Xeno]

Originally Posted by Poppyboy

If the car is smoking, not burning oil and your coolant is low, head gasket?

If I was more mobile, I could try to sort through my 2017 tax records but my memory is that the head gaskets were replaced within the last two years. Is that a job that a dealer would normally change a little north of $2K?

The deal SA mentioned something like this to me the other day, but I will need to call and verify the records as my memory in this lane is weak to say the least.

BTW, there is no more smoke for now. The dealer SA explained to me what he did but it was so minor there was no charge.

[jiggz]

Originally Posted by Sophisticated Redneck

I seriously doubt you need valve seals. No engine should need valve seals until 200k+ IMHO.

The N63 valve guide seals are notorious for failure anywhere between 50-120K miles. Quite a few members here have had them replaced.

Mine failed the test at 55K miles, BMW replaced them under CPO.

[Sophisticated Redneck]

Originally Posted by jiggz

The N63 valve guide seals are notorious for failure anywhere between 50-120K miles. Quite a few members here have had them replaced.

Mine failed the test at 55K miles, BMW replaced them under CPO.

They don't fail, they only wear quicker then intended thanks to the insane temps the engine is subjected to due to the tomb of a engine compartment. This in combination with an absolute JOKE of a CCV system allows zero tolerance when they wear a bit. Applying a proper amount if crankcase vacuum fixes this. My 2012 is the perfect example of this. Stock CCV system a she smokes like an old freight train after sitting at a stop light more then a minute not to mention the exhaust smelled like hell. I did nothing but setup the catch-cans with a proper amount of crankcase vacuum and no more smoke not to mention better performance and no more burning oil smell from th exhaust. So yes you can fix it with a 7k valve seal job, or 100 dollars in catch-cans and hoses. I chose the latter. Now eventually the seals may wear enough where even the proper amount of CC vacuum won't help..I'm at 130K, haven't seen it yet. Normally that's 200K+ for most engines.

I'll make a video of my exhaust idling with no CC vacuum and smoking and then one with it so people can see for themselves. I'm not saying it will solve all of the smoking n63s, but it will the vast majority of them and it's worth the time and 100 dollar gamble before you drop 7K not to mention the catch-cans catch so much crud that makes it past the stock oil/air separators that in itself will pay for it.

[Poppyboy]

Originally Posted by Xeno

If I was more mobile, I could try to sort through my 2017 tax records but my memory is that the head gaskets were replaced within the last two years. Is that a job that a dealer would normally change a little north of $2K?

The deal SA mentioned something like this to me the other day, but I will need to call and verify the records as my memory in this lane is weak to say the least.

BTW, there is no more smoke for now. The dealer SA explained to me what he did but it was so minor there was no charge.

Yes.

[Xeno]

I talked to the independent shop and they told me that value stem seals would leave a huge cloud of smoke coming out of the exhaust. I have not seen anything like that during normal driving nor again moments ago with normal driving. I have an appointment but they cannot do the valve stem seal job. They also mention that some people simply top off the oil faithfully to put off the major repair bill but for how long I do not know.

I then talked to Cooper BMW. He said that if the PCV valve was an issue, I would see the check engine light. He then went on to say that they idled my 2008 X5 for 15 minutes then hit the accelerator and then they saw a lot of smoke.

During this last run with my wife driving, we had to idle for 15 minutes at a vendor. I had her hit the gas and initially a large cloud of smoke came out of the left exhaust. However, it was brief and never saw any more smoke when pressing the accelerator before leaving that location.

Does this mean I have a valve stem seal issue but this is in the early stage and repairs can be put off for a while? I take it that once this job is undertaken that it is all or nothing so the agreed price stands because of all the manual labor involved.

BTW, the two previous big jobs by Cooper BMW were the timing cover gasket and the valve cover gasket. These were done in March 2016.

[philly42]

Replicate the scenario and record how much smoke comes out. Ensure the car is fully warm so the smoke is not mistaken for condensation.
Keep the oil change intervals around 4k. There are additives in oil that help that help valve seals. I don't think these additives last long.

[Xeno]

I am not aware of much oil consumption at least according to the dipstick and the green lights when doing a system check. This despite the constant warnings on the main screen about oil getting low.

I found a reputable independent who would do the job for $5K. I am also talking to the service manager at the dealer so we'll see where that lands.

In the meantime, my wife did a quick run this morning and the coolant icon returned. This despite the fact that I poured in most of a gallon yesterday. However, I do not remember smoke from the hood during 30+ minutes of street driving yesterday.
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[heatmizr]

Redneck what you are saying is really intriguing...
Can you help me understand how crankcase vacuum is correlated with the pressure/vacuum in the head / valve stem area? - is it the same? If that is negative, wouldn't that keep the oil from getting forced thru the valve stem seal (which is under pressure from the turbos half the time, and maybe not when off-throttle).

And how / where is the PCV system attached, and what impact it has on the pressures above?
Trying to understand how your fix works.

[Sophisticated Redneck]

Originally Posted by heatmizr

Redneck what you are saying is really intriguing...
Can you help me understand how crankcase vacuum is correlated with the pressure/vacuum in the head / valve stem area? - is it the same? If that is negative, wouldn't that keep the oil from getting forced thru the valve stem seal (which is under pressure from the turbos half the time, and maybe not when off-throttle).

And how / where is the PCV system attached, and what impact it has on the pressures above?
Trying to understand how your fix works.

Sure, so lets start at whats going on at Idle:

In any engine, the throttle valve is nearly closed, in essence choking the engine and starving it of air. This is true if its an old 50's truck with a carburetor on it or a fancy-pants BMW with direct injection and a electronically driven throttle valve.

This creates a vacuum, different depending on the many factors but in general most engines are around -20 psi At idle when you intake valves open, the are subjected to this vacuum. When your engine is new and the valve seals are super tight, no oil can get sucked through. However when shes been around the block a few times, the seals wear and now can allow some oil to pass.

As an engine wears it also increases its blow-by: this is the amount of gasses that go around the piston rings and into the crankcase. These gasses must be vented or ideally recycled back into the intake as they are quite nasty and thus why all engines have some form a PCV or CCV system. Within these gases is trapped oil, so some form of a oil/air separator must be used. In the 50i, these are tucked under the valve covers. They kinda suck though as if they did their job my catch cans would be dry and our engines would not have the carbon build issues they suffer quite often from.

BMW PCV systems are notoriously weak. They tune them for about -1psi. Thats all fine and dandy when the engine is new, put 100K on it though and the increased blowby with worn valvestem seals and you get the messy smoking at idle syndrome.

The reason why this goes away at part or full throttle is the vacuum in the combustion chamber goes to 0 at full throttle on a normal engine and on the 50i will go to 8 to 12psi depending on the temp. This eliminates the oil coming down through the valve stems and thus why our cars are notorious for smoking at idle but not when we are cruising down the road questioning why everyone drives so slow (if yours smokes while driving, its probably clogged turbo oil lines or shot turbo seals)

Below is a pic of the 50i's CCV (it uses two of these, plus tubes that go to each intake manifold on the engine) I whipped up. Its s two stage system as under boost the PCV valve must close as to not pressure the crankcase and it switches to the force of the intake air running past the CCV pre-turbo inlet to pull in Crankcase gasses and still create a mild vacuum under boost.

[Sophisticated Redneck]

Adding a catch-can system with an PCV valve, eliminating BMW's weak -1 tuned valve, allows the engine to get a proper -10+ PSI in the crankcase. It is possible to get to much, my first stab at it I hit with a full -20psi and it make the front crankshaft seal squeal like a slipping belt at idle. I drove it like that for about 5000 miles before I got tired of the looks at stoplights. DIdn't hurt anything but in theory it could dry it out and cause the seal to wear prematurely.. In general -20 is to much but -10 to 12 psi is a safe bet and can be tuned by your PCV valve selection. On any engine this will greatly reduce any smoking caused by valvestem seal wear. Eventually the seals will wear enough where you will have to replace them but by then its 200k+ miles and you are going to want to rebuild the entire engine anyway...