[MNR0]

What happens when VANOS fails? Is it terminal? What is it?

How do u know its VANOS? Like, only cold starts, zero power, limps etc...

Oh, the engine code logged is non-specific - ie., unknown...

[JamieA]

I can't say exactly, but as the VANOS controls the timing of the valve operation but adjusting the crankshaft, failure would be show up as reduced power and fuel economy, and perhaps smoothness, lumpy torque generation, and perhaps a reluctance to rev at the higher RPM ranges.

I guess this would depend on whether a failure makes the VANOS return to some safe mid-point, or whether it is stuck on where if failed, therefore leaving your engine optimised for either high or low RPM..

[JamieA]

I just did some quick googling, check these out:

http://www.dtmpower.net/forum/e36-3-...es-common.html

and

http://drvanos.com/

[WOPALX]

Originally Posted by MNR0

What happens when VANOS fails? Is it terminal? What is it?

How do u know its VANOS? Like, only cold starts, zero power, limps etc...

Oh, the engine code logged is non-specific - ie., unknown...

It happens from time to time and the car will go into limp mode but it should not be terminal by any means.

I had a vanos solenoid fail, caused limps when running through the gears. Get your $tealership to look at it.

[MNR0]

Weird thing is it happens when its cold. Can't drive it when cold. Like running on 2 cylinders... Limp mode. Very sick idle and lucky to get over a speed hump. Was an emeregency visit.

Economy has always been good - average 520-550 a tank between suburbs and lights - avg. speed 38km/h.

After it's warmed up a bit - a few restarts - its drivable again. But it was getting worse - much worser - after every cold start.

$tealership was suggesting valve problems. Hence why maybe VANOS. Dunno... could be HPFP. But then, why would it get beter when warm? Maybe something to do with oil pressure and something needing a warm car to work.

Anyway, will find out soon enough.

Im pissed that in less than 2 years the engine is undrivable - totally stock and regularly serviced. Seriously thinking about an LS3 wagon now. My old Gen3 never caused me one bit of trouble.

[WOPALX]

Originally Posted by MNR0

Im pissed that in less than 2 years the engine is undrivable - totally stock and regularly serviced. Seriously thinking about an LS3 wagon now. My old Gen3 never caused me one bit of trouble.

What happens when you leave it stock

I'm sure the dealer will sort it out for you, things break from time to time, but yes it sucks when it happens.

[JamieA]

You don't have a dodgy coil do you? I had a similar experience with my Audi and it turned out to be a coil

[MNR0]

Well I got word from the $tealership that there was excessive carbon build-up on the vales, causing the misfires and stopping regular valve motion. Now I would have thought the right thing would be to take the heads off, clean everything up, reseat the valves before putting it back togteher. But what happened was to pour solvent on top of closed valves and dunny brush the stems/valve backs and blow the crap out under compressed air.

My concern is now that some of that has leaked into the cylinders and on first start ringlands are heat shocked because of the solvents they used, carbon has scored the bores and it will blow more oil then before. All that while the cause has not been diagnosed. What about the valve guides?

It all sounds like a backyard mechanics way of pushing something back out the door.

Not impressed. Not sure what to do.

I was told it was not common and that it looked like the car had only seen 2-3km trips under cold start for its entire life. Yet average sped is 40km/h and Ive done 43K+ in 1yr 8 months.

[WOPALX]

I think we will find this is more common due to the direct injection as the fuel is not coming in contact with the valves and therefore the cleaning agents in the fuel are not doing what they are designed to do. So the buildup gradually catches up with you.

I suggest raising your concerns about possible future oil consumption and keep a log book each time you have to add oil. Also do some searches as I'm sure others have had more extensive head work to rectify the issue in the US.

One potential way to keep these parts clean would be meth injection ... maybe suggest that to your SA

[John_01]

Originally Posted by WOPALX

I think we will find this is more common due to the direct injection as the fuel is not coming in contact with the valves and therefore the cleaning agents in the fuel are not doing what they are designed to do. So the buildup gradually catches up with you.

Um, which cars have direct injection? I thought it was only N53 series engines sold in Europe that use direct injection.

[Sparky66]

Originally Posted by John_01

Um, which cars have direct injection? I thought it was only N53 series engines sold in Europe that use direct injection.

The N54 engine fitted to the 335 is direct injection.

As to where a good place to have the carbon buildup on the valves, injectors and the complete combustion chambers professionally cleaned and removed, I highly recommend the services of MRT Performance at Rhodes (Sydney).
They offer a BG Liquitech Fuel System & Throttle Body Service.
Go here for details:http://mrtperformance.com.au/content/view/690/53/

[WOPALX]

Originally Posted by Sparky66

The N54 engine fitted to the 335 is direct injection.

As to where a good place to have the carbon buildup on the valves, injectors and the complete combustion chambers professionally cleaned and removed, I highly recommend the services of MRT Performance at Rhodes (Sydney).
They offer a BG Liquitech Fuel System & Throttle Body Service.
Go here for details:http://mrtperformance.com.au/content/view/690/53/

Sparky66,

How does they apply this cleaner?

Cheers,

S

[MNR0]

Some more news...

Some tests were done on the PCV valve in the rocker cover and it was found to have an intermittent fault (it's just a valve so who knows). Waiting on a replacement rocker cover to come in from Germany (2-3 weeks).

[John_01]

Originally Posted by Sparky66

The N54 engine fitted to the 335 is direct injection.

Thats good to know. Thanks!

[meinauto]

Originally Posted by MNR0

Some more news...

Some tests were done on the PCV valve in the rocker cover and it was found to have an intermittent fault (it's just a valve so who knows). Waiting on a replacement rocker cover to come in from Germany (2-3 weeks).

Hi, can you elaborate what tests were done to ascertain that the PCV valve had an intermittent fault?

[MNR0]

Symptomatic issues related to:

poor idle quality
wanting to stall
absolutely no power on take-off

Doncaster BMW would not say how they identified the PCV valve being faulty, only that they performed some "tests" to indicate an intermittent fault with the PCV system

I am still waitign for the problem to be fixed. Its been 3 weeks now and Im still driving around in a 4cyl 320 but paying for a 6cyl TT.

Personally, I don't see how the problem is related to the PCV system, but Im not a BMW tech and so don't know how integral the PCV system is.

[Attila_the_Bum]

Hi All, thought I would share my experience with you. Same as MNRO, one morning the E92 335i cold start was very lumpy but as engine warmed up - no problem. Didn’t do it again for a few days but then same again - reduced power light on, limped down the road and as engine warmed, again no problem. Next day much, much worse - third day un-drivable with a cloud of white smoke out the back when accelerator pressed! Towed to Melbourne BMW.
That was 5 (Yes Five) weeks ago. Still no car, but I have been given even less info than MNRO.
I was told the same info about carbon build up on valves (Stealership asks "Do you use premium unleaded?" Please!). Told they needed to replace rocker cover - had to wait for one from Germany etc. Told, several times, they had removed carbon build up (MNRO comments really worry me now I’ve read his post) and latest is they are replacing all 6 injectors.

It just seems no one knows whets wrong with the car or they are not prepared to throw enough resources at it to fix it (by this I mean money)!

MNRO - is your problem fixed? Did you get a decent explanation as to what the problem was? I will let you know what happens with mine.

[MNR0]

Hi Attila,

No, problem still exists. Car has been offr road for 1 month now. No explanation yet short of PCV valve. Seems like you have the same problem. At least they are saying they will replace the injectors.

Will keep you updated when i know more.

[Attila_the_Bum]

Picked the car up today! Finally BMW say its perfect, and I must say it certainly seemed to fly on the way home. We will do a very cold start tomorrow and see.......

Basically it seems that they descaled the carbon build up from valves, replaced the rocker cover, replaced all 6 injectors, and completely updated and reprogrammed the engine management software with some new codes.

I still dont think they really know what was wrong with it but they are happy with the car now. If no more posts assume its fixed - Yah!

Good luck MNRO - let us know what your result is.

[adrock]

Originally Posted by Attila_the_Bum

Hi All, thought I would share my experience with you. Same as MNRO, one morning the E92 335i cold start was very lumpy but as engine warmed up - no problem. Didn’t do it again for a few days but then same again - reduced power light on, limped down the road and as engine warmed, again no problem. Next day much, much worse - third day un-drivable with a cloud of white smoke out the back when accelerator pressed! Towed to Melbourne BMW.
That was 5 (Yes Five) weeks ago. Still no car, but I have been given even less info than MNRO.
I was told the same info about carbon build up on valves (Stealership asks "Do you use premium unleaded?" Please!). Told they needed to replace rocker cover - had to wait for one from Germany etc. Told, several times, they had removed carbon build up (MNRO comments really worry me now I’ve read his post) and latest is they are replacing all 6 injectors.

It just seems no one knows whets wrong with the car or they are not prepared to throw enough resources at it to fix it (by this I mean money)!

MNRO - is your problem fixed? Did you get a decent explanation as to what the problem was? I will let you know what happens with mine.

What do you mean by "cold start was very lumpy". Was it a sound or did your car not actually have any power?

Thanks!

[Attila_the_Bum]

Reduced Power - Spluttering and kangeroo hopping - Felt like the engine was trying to run with no fuel or too much fuel on firing on a couple of cylinders.

[MNR0]

Originally Posted by Attila_the_Bum

Picked the car up today! Finally BMW say its perfect, and I must say it certainly seemed to fly on the way home. We will do a very cold start tomorrow and see.......

Basically it seems that they descaled the carbon build up from valves, replaced the rocker cover, replaced all 6 injectors, and completely updated and reprogrammed the engine management software with some new codes.

I still dont think they really know what was wrong with it but they are happy with the car now. If no more posts assume its fixed - Yah!

Good luck MNRO - let us know what your result is.

How long did they have the car to fix your problems? Was it an in-n-out affair?

Anything will fly compared to driving a 320i for a month...