Buddy of mine has a smoking 750Li....

4964 Views 28 Replies 8 Participants Last post by wp745i, Nov 13, 2014

ndcsucks

Discussion Starter · May 16, 2014

Hey gang...

A buddy of mine has a 2007 750Li with 90,000 Km on it. He was asking me about why he is starting to see smoke from the tailpipe when at idle then taking off from a light, sometimes.

I went to his place to do the usual idle check and then punch it after 10 mins or so...

Tried 3 or 4 times and very little smoke came out... Just a very light puff of blue. He said he had seen it much worse.
The car was on a slight hill facing uphill when we were testing... So I drove the car around the block and parked it in the opposite direction. Nose of the car is now facing down hill.

Let her idle for 10 mins and punched it... POOOF!!! huge white / blue cloud... ;-)

Tested again... POOF!!! same thing

Spun the car around again, facing uphill... 10 mins later, punched the throttle, almost nothing...

My car used to do it all the time, before doing my valve seals.

Before he and I jump into the motor to replace his seals...

Is this normal behavior for valve seals, or could it be sumth else?

Thanks.

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1 - 20 of 29 Posts

White94RX

· #2 · May 17, 2014

It's valve seals. It always is on the N62 engine

BMW Level 1 Master Tech
2006 E60 M5
2006 E60 525i
2001 E39 540i (for sale)

A B Able Truck

· #3 · May 17, 2014

What's odd is that the smoke changes with the direction of the vehicle - you may want to read thru this thread;

http://www.bimmerfest.com/forums/showthread.php?t=751740&page=3

***

switz

· #4 · May 17, 2014

It's the seals. Fronts are just worse.

ndcsucks

Discussion Starter · #5 · May 17, 2014

Puff

Thanks guys..

Great reading on the link provided.

I am gonna try the forcing of the VT system to failsafe, by pulling the solenoids... See if that helps him out as a start.

I agree... I do believe it to be the seals as well...

Mine were cooked, and had about the same mileage on the car.

A mechanic buddy of mine said the true fix is new guides, larger valve stem valves and new seals.

Doing the seals only, will buy ya a couple years.. then it will start to come back.

Thanks again.

A B Able Truck

· #6 · May 17, 2014

ndcsucks said:
Thanks guys..
Doing the seals only, will buy ya a couple years.. then it will start to come back.
Thanks again.

There is an updated valve stem seal that eliminates the cavity that forms as the seal wears. This cavity allows the oil to pool at the top of the valve guide. In my mind, this makes perfect sense and will have to see over time if the problem resurfaces without changing guides.

ndcsucks

Discussion Starter · #7 · May 17, 2014

That's good. I did mine last year. I got the seals from BMW, so I hope they were the updated ones.. haha.

No smoke .... yet.

ndcsucks

Discussion Starter · #8 · May 17, 2014

Tried the solenoid fix as per the link above...

Performed the procedure as per the link that A B Able Truck mentioned..

So we played with by buddies car today...

Pulled all 4 connections off the Vanos solenoids. Went for a drive and then parked it facing down hill... Let her idle for about 10 mins. Gave the throttle a punch..There was a little bit of blue smoke. Not the massive cloud of blue /white like yesterday... Much less!!!

We then drove around some more, and tested it again... and again some smoke.. but less the first time... nice...

We are gonna leave it this way until next weekend to see if the smoke all but disappears.

It's definitely better, right out of the gate

Car drives well... Idle is around 700 RPM vs. the 500 RPM it is usually idles at. And the engine light is on because of the 4 codes in memory.

I will update as we go....

Thanks.

A B Able Truck

· #9 · May 17, 2014

ndcsucks said:
Performed the procedure as per the link that A B Able Truck mentioned..
So we played with by buddies car today...
Pulled all 4 connections off the Vanos solenoids. Went for a drive and then parked it facing down hill... Let her idle for about 10 mins. Gave the throttle a punch..There was a little bit of blue smoke. Not the massive cloud of blue /white like yesterday... Much less!!!
We then drove around some more, and tested it again... and again some smoke.. but less the first time... nice...
We are gonna leave it this way until next weekend to see if the smoke all but disappears.
It's definitely better, right out of the gate
Car drives well... Idle is around 700 RPM vs. the 500 RPM it is usually idles at. And the engine light is on because of the 4 codes in memory.
I will update as we go....
Thanks.

So if you think about it you're doing 2 things;
- You're decreasing the piston produced vacuum in the cylinder that would have increased the likely hood of sucking oil where it could (past valve stem seals & rings)
- You're increasing intake manifold vacuum which is going to pull, seal and hold the CCVs better (But what effect will that have on purging blow by pressure from your crankcase?) If applicable, you may want to impede the oil dipstick o-rings from sealing to protect gaskets & seals while you're doing your test.

ndcsucks

Discussion Starter · #10 · May 17, 2014 (Edited)

Understood.. ;-)
Just called him, and told him to pull the dipstick out a bit so it can breathe a little.. ;-)
Thanks man.

nguyennhatquang

· #11 · May 19, 2014

It has valve stem seal problem.
My car has same,, oil catch can will be good.. It protect your intake manifolb, i has both done

ndcsucks

Discussion Starter · #12 · May 19, 2014

I was thinking of getting an oil catch can for my car... as I do see oil residue in that connector leading into the intake from the valve covers...

if CCV's are working as they should, there should be very little oil and gasses getting into the intake anyways I would think?

A B Able Truck

· #13 · May 19, 2014

ndcsucks said:
I was thinking of getting an oil catch can for my car... as I do see oil residue in that connector leading into the intake from the valve covers...
if CCV's are working as they should, there should be very little oil and gasses getting into the intake anyways I would think?

$40 & 1 hour labor - works great (CCV hose configurations vary)

http://www.bimmerfest.com/forums/album.php?albumid=10118&pictureid=39148

nguyennhatquang

· #14 · May 19, 2014

ndcsucks said:
I was thinking of getting an oil catch can for my car... as I do see oil residue in that connector leading into the intake from the valve covers...

if CCV's are working as they should, there should be very little oil and gasses getting into the intake anyways I would think?

1st time i had the same thinking as you, but i check a lot of bmw even the brand new one still the same. => bmw pcv is junk... But when car new they didnt burn oil.
I did add oil catch can for my car and it only catch about less than .5 quart in 3000 miles.
The main problem is still the valve stem seal.
But if u want protect your bmw. The best is both ...

If u continue to drive the car like that. U ll damage the cat. Fault code 2c32 or 2c31 will set and u ll need new cat

ndcsucks

Discussion Starter · #15 · May 21, 2014

Cool...

Ordered a catch can... Should be here in a week or so.. I am gonna give it a try, as my car still goes through a bit of oil.. ;-)

Thanks for the tips.

switz

· #16 · May 21, 2014

Don't waste your time with band aids. You have to do the stem seals or it will kill your cats and secondary air ports in no time.

Save

ndcsucks

Discussion Starter · #17 · May 21, 2014

I did my seals 9 months ago. My car does not smoke. But I still go through a bit of oil.
My friends car is the one who has the seal issue.
I'm curious if my oil consumption is from my CCV's they are both brand new, but have read on other forums that the BMW CCV's in general are crap.

Sent from BimmerApp mobile app

switz

· #18 · May 21, 2014

Compression check to see if the rings are good?

nguyennhatquang

· #19 · May 21, 2014 (Edited)

never seen any N62B48 need new piston ring..
it is a BMW..it is not a junk Cadillac

ndcsucks

Discussion Starter · #20 · May 21, 2014

I had a leak down and compression test done by Bimmer dealer done last year as part of another issue I had at the time... Bothe test came back good.

I had a minor rattle at light loads. Turned out to be the timing chain hitting a high spot on left over casting material on the block, left over from when the block was made by the factory. I could see where it was hitting when I opened her up. Once I was that far, I decided to do the valve seals as well.

I have no oil leaks... I fixed those up when I replaced all the gaskets, when doing the valve seals... She is nice and dry in the engine compartment..

But I will still go through a liter of oil every 3 thousand Km or so... Seems wrong.

My 2003 Toyota 4runner never has used a drop. Just change it every 6000 clicks or so.

Bimmer tried to tell me that the oil consumption is "Normal" :-(

1 - 20 of 29 Posts

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