New S4 B8 owner, oil consumption issue, looking for advice..

[Blazius]

Hello

I recently became the owner of an B8 S4, 2010 , CCBA engine , 140k miles, pretty good looking car and options but a "minor" issue is present :D

So the thing is the car is smoking on idle, and is definitely smoking on a WOT pull and by smoke I mean visible in mirror kinda blue smoke. Am I looking at a ring rebuild ?
I've done a compression test it came back okay not new but not alarming. Looking into cylinders they look okay, but cylinder 6 is quite coked with carbon from the looks of it and ofcourse this is the bank that has more smoke visible from tailpipe.
Also I've done a piston soak via ATF/Toulene mix because B12 is not available here in Europe really but doesnt seem like it helped much even tho oil came out pretty dark and stuff.

I drove 8km on it so far since oil change but the oil level is still at max which is weird at this much visible smoke I'd assume it wouldve consumed a decent chunk by now(give that the sensor reads like 0.7-1 liter change or so.

I've tried checking the PCV via removing the cap and its not hard to remove at all, and the engine doesnt change note at all, from what I've read if pcv is at fault you can barely remove the cap and the car should run rough but IMO if I remove the cap it should still stumble atleast with a good PCV system.

From the severity of the burning I would assume its a ring job but lets see what yall have to say. If need be I can probably post a video from idle but really its worse when driving.

Thanks!

[Nillious]

Put a vacuum gauge on the dipstick tube and see what the vacuum is at idle. Unless. It has the updated pcv and software it should be 30 mbar. Newer pcv and updated software will be 150 mbar.

[LowKeyLoki]

If you are going by the gauge on the MMi screen and don’t have an actual dip stick, then you have no idea if that sensor is malfunctioning and reading correctly and have no idea what the oil level actually is. Those sensors in the oil pan they fail all the time.

[Blazius]

Put a vacuum gauge on the dipstick tube and see what the vacuum is at idle. Unless. It has the updated pcv and software it should be 30 mbar. Newer pcv and updated
software will be 150 mbar.

Unfortunately I do not own a vacuum gauge except a vacuum/boost gauge that I can use to check , 30mbar of vacuum would be pretty hard to detect but I guess if needle moves its okay.
But I can definitely tell you the ecu is the A version (i have vcds among other software) so no D revision for updated pcv.


If you are going by the gauge on the MMi screen and don’t have an actual dip stick, then you have no idea if that sensor is malfunctioning and reading correctly and have no idea what the oil level actually is. Those sensors in the oil pan they fail all the time.

I do have a dipstick and I just checked it cold and its full so Mmi reading correct aswell.

[carguy19]

Hello

I recently became the owner of an B8 S4, 2010 , CCBA engine , 140k miles, pretty good looking car and options but a "minor" issue is present :D

So the thing is the car is smoking on idle, and is definitely smoking on a WOT pull and by smoke I mean visible in mirror kinda blue smoke. Am I looking at a ring rebuild ?
I've done a compression test it came back okay not new but not alarming. Looking into cylinders they look okay, but cylinder 6 is quite coked with carbon from the looks of it and ofcourse this is the bank that has more smoke visible from tailpipe.
Also I've done a piston soak via ATF/Toulene mix because B12 is not available here in Europe really but doesnt seem like it helped much even tho oil came out pretty dark and stuff.

I drove 8km on it so far since oil change but the oil level is still at max which is weird at this much visible smoke I'd assume it wouldve consumed a decent chunk by now(give that the sensor reads like 0.7-1 liter change or so.

I've tried checking the PCV via removing the cap and its not hard to remove at all, and the engine doesnt change note at all, from what I've read if pcv is at fault you can barely remove the cap and the car should run rough but IMO if I remove the cap it should still stumble atleast with a good PCV system.

From the severity of the burning I would assume its a ring job but lets see what yall have to say. If need be I can probably post a video from idle but really its worse when driving.

Thanks!

You need to get some good diagnostics on the car before you assume that the rings are bad and tear into the motor. It could be PCV, it could be a valve seal. You should have someone in the know do a compression and leakdown test to figure out where your issues are stemming from. It's completely normal for our cars to use a quart of oil between oil changes every 5-7500 miles even with a fresh carbon cleaning, new PCV and full tune up on the car.

[STXA7]

Are you using the sacred liquidmoly leichlauf 40w? if not then wtf bro. also i think it's badass that you did the piston soak method, i'm too chicken to try it.
Did you get blue tailpipe smoke BEFORE or AFTER the piston soak? i would imagine you would get an increased amount for some time after doing it. might even do another fresh oil change after a full tank of gas 400miles approx. see if that improves things. also listen to the guy that says you need to get actual good diagnostic work before you fire the parts cannon.

[carguy19]

Are you using the sacred liquidmoly leichlauf 40w? if not then wtf bro. also i think it's badass that you did the piston soak method, i'm too chicken to try it.
Did you get blue tailpipe smoke BEFORE or AFTER the piston soak? i would imagine you would get an increased amount for some time after doing it. might even do another fresh oil change after a full tank of gas 400miles approx. see if that improves things. also listen to the guy that says you need to get actual good diagnostic work before you fire the parts cannon.

400 miles out of 1 tank of gas? Do you only drive downhill? LOL

I am on my 4th B8/8.5 S4 6spd manual that I have owned, and I have never gotten more than 330... maybe 340 out of a tank..... and that was on a long trip where I was pretty much not slowing down or stopping at all.

If I had to say what my average is on a full tank, I would say I am 280-310 typically. That's mixed highway and city driving with a few more than half throttle blasts from stoplights. :D

[Blazius]

So since I have started this thread I've put some kilometers or miles on this car. The oil consumption is about 1L per 800km, which is unacceptable in my opinion also the visible smoke on idle and WOT is not something I wanna live with forever :) but lets break it down:


You need to get some good diagnostics on the car before you assume that the rings are bad and tear into the motor. It could be PCV, it could be a valve seal. You should have someone in the know do a compression and leakdown test to figure out where your issues are stemming from. It's completely normal for our cars to use a quart of oil between oil changes every 5-7500 miles even with a fresh carbon cleaning, new PCV and full tune up on the car.

As mentioned I have done compression test myself, I am not new to cars or building engines etc.since I also had(have) a B5 1.8T big turbo build I did myself. I also tune cars :) (hit me up if intersted btw) but anyway compression test came back above the wear limit which was also done cold and dry so while hot and running with oil in there its prolly even much better.
Leakdown not done yet but yes it should be done I agree, it will tell me even more info but as of now I am leaning towards the PCV for a big part of the consumption issue, why:

I can confirm I have a coolant loss aswell, not major but visible after a few hundred miles, also I have recently done VC gaskets and noticed some antifreeze in the oil
so very likely the seal has failed on the PCV and diluting the oil which I can also probably confirm since sometimes rarerly I can hear the chain on hot idle , which is a common thing when this happens

The car is on original software A revision which means it has the 30mbar PCV, so I have purchased the 150mbar version (AH latest p\n) and I will replace it in the following days and update software to D revison as mentioned in TSB

Car smokes when coming to idle only when HOT, idle when hot, when setting off HOT, and on WOT.


Are you using the sacred liquidmoly leichlauf 40w? if not then wtf bro. also i think it's badass that you did the piston soak method, i'm too chicken to try it.
Did you get blue tailpipe smoke BEFORE or AFTER the piston soak? i would imagine you would get an increased amount for some time after doing it. might even do another fresh oil change after a full tank of gas 400miles approx. see if that improves things. also listen to the guy that says you need to get actual good diagnostic work before you fire the parts cannon.

No problem doing the soak unfortunately I dont think it has helped much, I cannot get the mix exactly the same as B12 chemtool which works great from what I am seeing and unfortunately I cannot get it in europe,so might have to ask someone to ship it to me or something in the future :)

As for oil I was using good quality oil like Shell Helix Ultra which is comparable to LM oil if not better according to oil analysis and so on. Also ceratec done and such. But ofcourse will try more combinations with great oils and additives to clean the CC and rings.

Ofcourse after you do the soak it will smoke like mad for a few mins to clear up, its normal.

[BrokeBichB8]

Oil cap comes off easy during idle then you have a trashed pcv. Change the pcv. I had the same issue. pcv with low vacuum at idle did 1000miles per quart of oil. now I go 5k miles per quart.

[B 2]

Oil cap comes off easy during idle then you have a trashed pcv. Change the pcv. I had the same issue. pcv with low vacuum at idle did 1000miles per quart of oil. now I go 5k miles per quart.

Not OP but I recently did mine and have around Half L per 1000miles. Same as before. Valve gaskets done within 15k miles too. Any other ideas?

[Blazius]

Oil cap comes off easy during idle then you have a trashed pcv. Change the pcv. I had the same issue. pcv with low vacuum at idle did 1000miles per quart of oil. now I go 5k miles per quart.

It does not come off "easy" as I can feel some suction still, like I can definitely there is vacuum present. But anyway I will be replacing the PCV on the weekened hopefully and it I hope it sorts out the consumption issue mostly but to be honest I dont believe it will fix all ofcourse.
We will see and I'll post here accordingly.

[Blazius]

So I do have an update on this engine/car, unfortunately its not a good one:

After a mild overtake, once I let of the gas I felt heavy engine "braking" and 5 seconds later the engine seized up, I instantly knew once the RPM dropped to 0 mid drive.
Looks like it will be a more complicated repair than I thought so :)

Let this be a lesson, if you have mysterious coolant loss big chances its the PCV leaking into oil, or the SC cores which CAN cause hydrolock, do NOT ignore it too long or this will happen.