Having issues with my N54 135i

[Stupenal]

I don't know if the n54 would have this issue, but the n52 with a bad idle can be attributed to the eccentric shaft sensor. Oil apparently gets in the plug and fouls the sensor. My symptoms were anidle that would randomly dip, warm or cold engine. It felt as if a "lump" was passing through the exhaust as it would shake the whole car when the idle would dip.

[TheRuss]

Would that likely cause the timing to be retarded as well? And would it throw a code?

[TheRuss]

Not sure what the best way to show the logs is - so any help would be appreciated.

Here's a link to a couple of the logs that I did on the stage 2 aggressive tune, with Shell's premium fuel - the first is a cold start, the second is light throttle acceleration up through all gears (engine still cold):

http://www.datazap.me/u/theruss/cold...12-13-14-15-16

http://www.datazap.me/u/theruss/ligh...12-13-14-15-16

Cobb support says the timing is being pulled and looks really unusual - but I have no idea how to read these things.

Any light that anybody can shed would be greatly appreciated, as I really have no idea what to do for the best right now and the car is still not throwing any codes (or at least none that are readable by the Cobb) nor a CEL.

Edit: I also have logs of the car running a stage 0 tune on Shell fuel and another set running stage 2 Drive map with a premium supermarket fuel (just to check it wasn't the fuel). If it'll help to show these then just ask and I'll throw them up. I just don't want to drown everyone in logs straight away.

Edit2: I went ahead and uploaded most of my logs, hopefully you can see them all by going here: http://www.datazap.me/u/TheRuss

[TheRuss]

A little bump just to see if anybody could fathom anything from what I posted?

[135iam]

With 1 month left in my warranty I took my 2010 135i in to the dealership requesting new spark plugs as it stumbled when cold, and only on cold starts. They pulled the spark plugs and put them back in. Then what really surprised me is that they replaced all the injectors and the car has been smooth starting ever since.

[TheRuss]

Would injectors cause the timing pulls though? I don't have any BMW warranty, but a different extended warranty that was given when I bought the car. Not sure that it'd cover anything unless the car actually broke down though.

[135iam]

Originally Posted by TheRuss

Would injectors cause the timing pulls though? I don't have any BMW warranty, but a different extended warranty that was given when I bought the car. Not sure that it'd cover anything unless the car actually broke down though.

I was stock and not logging at the time so I am not sure.

[TheRuss]

Ah right. That's my issue. I have DP's, and it's such a pain in the arse to swap them back to take the car in, although if it's not under BMW warranty is there any point in removing them?

[chdavis]

Have you replaced the CPS yet like multiple people have suggested?

I'm a little confused regarding the pushback on your end of not wanting to replace the CPS...

[TheRuss]

I was told by the BMW specialist that I use that if the CPS was faulty it'd throw a code. I have no codes. If it's that simple then I'd jump at the chance to fix it, however, I don't want to throw money at parts if they're not faulty. Is it not correct that it'd throw a code if it was bad?

Plus if I replaced everything that everybody suggested without investigating first then I'd have new injectors, coils, HPFP, VANOS, etc... I doubt all of those are faulty, though it could be any one of them. Without fault codes it's somewhat difficult to identify though - hence my throwing the logs up in the hope that they reveal something or that somebody can make suggestions on how to do further diagnosis.

[TheRuss]

Just had another abysmal start with the car chugging and the rpm needle flicking up and down. Almost seems like it's about to stall, so I touch the throttle to help it come to life, but even then it takes a few seconds to straighten out. It's almost like it's not running on all six when I start it, but I'm not knowledgable enough to know whether that's the case or not.

Weirdly, it kinda went silent at about 1500rpms today, barely any noise from the exhaust until I touched the throttle, which brought the BMWP exhaust's deep tone back. Not sure if it kinda stalled, or that was a sign of it missing on some cylinders or what?

I don't think it's the injectors though - the car sat all weekend and started OK this morning at home - it always starts fine at home because I use an oil pan heater to warm the oil up a little in the mornings. That seems to "cure" the starting issue. Then it started like crap (as described above) as I left work today in the evening, despite having been sat for far less time. Also, we didn't notice any oddness when we changed the plugs last year (using BMW plugs), and BMW reported that fuel pressures were fine, so I don't think it's the HPFP. Today's start happened with the alternative fuel that I tried, so I don't think it's the actual fuel, either. I'm thinking more along the lines of ignition, though I just checked and despite the awful start, still no codes (that my Cobb can read).

Could coil pack issues cause all of this (including the timing corrections across all cylinders?) or the CPS maybe?

[TheRuss]

Ok, so I managed to record a poor start today, because my car started awfully yesterday, so I guessed it would again today. Today's isn't as bad as yesterday's, but you get the idea. I kept the door open so you could hear the exhaust note more easily. It goes oddly silent just after startup and the initial high revs, then the revs drop too low and it nearly stalls.
N54 135i odd startup:

[Alow]

Originally Posted by Stupenal

I don't know if the n54 would have this issue, but the n52 with a bad idle can be attributed to the eccentric shaft sensor. Oil apparently gets in the plug and fouls the sensor. My symptoms were anidle that would randomly dip, warm or cold engine. It felt as if a "lump" was passing through the exhaust as it would shake the whole car when the idle would dip.

This happened to me too. The eccentric shaft sensor caused the exact same symptoms. I don't know if it would pull the timing too because I didn't look at that, but it sounds very similar.

Have you had your valve cover gasket changed? Has it leaked in the middle two cylinders? When you look at the valve cover, is there crud (dry oil) by the front of the car where the eccentric shaft sensor is? If one of those is true, it's very possible your problem is that sensor. Mine didn't throw a code until the sensor completely expired.

[TheRuss]

Ok, finally got a code. Looks like it was the HPFP all along, despite no long crank.

[the1andonly]

Originally Posted by Alow

This happened to me too. The eccentric shaft sensor caused the exact same symptoms. I don't know if it would pull the timing too because I didn't look at that, but it sounds very similar.

Have you had your valve cover gasket changed? Has it leaked in the middle two cylinders? When you look at the valve cover, is there crud (dry oil) by the front of the car where the eccentric shaft sensor is? If one of those is true, it's very possible your problem is that sensor. Mine didn't throw a code until the sensor completely expired.

"I don't know if the n54 would have this issue, but the n52 with a bad idle can be attributed to the eccentric shaft sensor. Oil apparently gets in the plug and fouls the sensor. My symptoms were anidle that would randomly dip, warm or cold engine. It felt as if a "lump" was passing through the exhaust as it would shake the whole car when the idle would dip."


My car has behaved like this since I got it new…it now has 30,000 miles and it and hasn't gotten any worse. Is this something I should have looked at? It kinda sounds serious the way you describe it. Will my car just fail to start one day because of this?