N62 valvetronic servo question

gaffinfool · #1 10-05-2016, 12:19 PM

I posted this last night in an old thread, because my issues are exactly as described here:

http://www.xoutpost.com/bmw-sav-foru...lue-smoke.html

I could not solve my issue like he did, as all of my sensors are plugged in.

05 X5 4.4

I made the mistake of not releasing the "tension" on the valvetronic servo when I removed it, and it popped out when I removed the 4 bolts. When I reinstalled it at the end of the job, I installed the servo by just screwing it back (turning the whole motor, not allen keying the shaft) into the VC until the surfaces met, the servo orientation was correct, so I screwed it down, and finished it up.

Hop in, did the key on, off, on, and fired it up. Idle is smooth, and in PARK, I can pretty much redline it and there are no issues - great throttle response, no extended high RPM's on the way back down - so I'm headed around the block for the first drive. Back it out, drop it in DRIVE, ease on the gas and now we're movin! High fives all around!!!

Ego kicks in because I have conquered this PITA job and I step on it, and the truck goes to bucking and hesitating. I also discovered I could drive it in manual, and as long as I keep the RPM's above 2k, I can't necessarily mash the gas to accelerate to pass, or go up a steep hill in higher gears, but I can get enough power out of it to run 70 down the highway with essentially no issues. But, I want to be able to mash the gas....

I did a LOT of research on the "go-go-gadget smokescreen" (I LOVE that term!) before deciding that this issue has ABSOLUTELY NOTHING TO DO WITH VALVE SEALS (my vacuum leak was actually the upper timing chain cover / driver's side). I understand the workings of the VVT setup, and how it replaces the throttle body to control how much air enters the cylinders.

My current issue feels like a carb with a full choke. If I feather the pedal, I can get the engine to "come back". And, because of this feeling, and what I understand about the VVT, I'm wondering if I just need to remove and reinstall the servo, and try to set it correctly. It makes sense in my mind that the computer recognizes the request for acceleration, pumps more gas into the cylinders, and sends the signal to open the valves more for more air, but maybe because of how I installed the servo, it's just not able to open them up as much as it should be able to.

I found the instructions on pelican on the servo removal and install. I'm going to try reinstalling it, but I guess I'm asking, are there any other adjustments I need to make, other than unscrewing/screwing the servo shaft? I saw something in my searches where someone was talking about having to spin the gear on the eccentric shaft, and hold it, along with the servo while installing it. It wasn't on the N62, but for as much of a gearhead as I am, I'm still learning about this beautiful, over-engineered tank. Maybe I'm barking up the wrong tree, and I should be looking elsewhere. I have tried to troubleshoot, but the only step I have taken so far is to unplug the newly replaced eccentric shaft sensor I so eloquently shattered when I was removing the VC, as I am really hoping I don't have to pull the VC off again. The issue remained.

TL;DR

If the valvetronic servo popped out when removing it during VCG job, are there extra steps above and beyond just screwing/unscrewing the servo shaft?

Sponsored Links

crystalworks · #2 10-05-2016, 02:50 PM

I probably won't be much help with this, but can you pull any codes from the ECM (specific BMW codes, not CEL OBDII codes)? That's typically the first step when diagnosing these tanks as you so appropriately called them.

gaffinfool · #3 10-05-2016, 04:50 PM

I did, but from the local O'Reilly's. I got the same P115A code that McDonaldD got in the referenced post. There's no DTC listed according to them. Hell, the all holy Google only brings back that post when I search p115a BMW.

The local indy wants 89 bucks to hook it up, and I'll probably end up there, but I'm just trying to knock out the "easy" stuff - what might I have done wrong - beforehand.

electricalserv x5 · #4 10-05-2016, 09:00 PM

Hello my n62 brother ,look into this a bit,but check and make sure the ISM is cheap and easy to install. IVM Replacement / Troubleshooting - Bimmerfest - BMW Forums

gaffinfool · #5 10-08-2016, 09:20 PM

It's somewhere else to look. I'm at a total loss.

I redid the valvetronic motor, verified my cps's weren't switched (I actually left the pigtail-less one in the VC when I did the gasket, so I know they weren't, but stranger things have happened, I guess), and this morning I cleaned and switched the Vanos solenoids. Still having the same issue.

He didn't give me the exact codes, but I had the O'Reilly guy check the codes again, and along with the P115a, I am also getting intake/exhast CPS errors.

I don't understand how just changing the VCG would kill both sensors, as there were NO issues with them beforehand.

Maybe I'm chasing a short now...

crystalworks · #6 10-09-2016, 12:43 AM

Perhaps you pinched a wire(s) under a valve cover? Seen that cause shorts before.

gaffinfool · #7 12-06-2017, 06:15 PM

What a freaking year it's been!!!

I have researched and researched this issue, had to replace the steering rack (found a great video on YouTube that made that job not as hard as it probably could have been and also BIG props to The Rack Doctor for the reman rack), had to replace the entire front suspension ("upper" ball joints - don't fight it and just go ahead and pull the whole spindle off the truck, put it in a vice, and use a 19mm socket to beat it out from the back (trust me this will save you so much heartache - there just isn't enough room to swing a hammer at the correct angle with it installed on the truck) and axles (no axle/cv joint issues, but did have ripped boots, so while I was in there doing the suspension, and 100k miles on them, why not) and also replaced my expansion tank, and last night, I fixed my problem.

I'm not totally sure what my issue was, but it was one of two things:

side note - ((***I left this out of the original post, but it could be a significant driver of this issue: originally, I snapped my eccentric shaft sensor when doing the driver side valve cover/timing chain gaskets to eliminate my smoke issue after extended idle (the Go-Go-Gadget Smokescreen) -- this is NOT a valve seal issue, DO NOT let anyone convince you that it is. The issue is fixed because they change the gaskets that are causing the vacuum leak that is causing the issue, but you've overkilled the repair!!! And being the cheap SOB that I am, I ordered an aftermarket sensor off of Amazon.***))

1) In the past year of research, one of the things I came across was that one of the springs popping off of the intermediate levers could cause a misfire (had an intermittent misfire code on cylinder 5). I had put the repair off because of how much of a PITA getting the valve cover off was, and that if I used Sport Mode, I could overcome the hesitation, and my truck would still run like a scalded dog down the highway, but finally decided it was time to crack it open and figure this out once and for all. The springs were all in place, so I was kind of bummed being back at square one. Since I had the cover off, my wife and I re-discussed the possibility of it being the Amazon.com eccentric shaft sensor, and I went ahead and ordered a new OEM sensor from FCPEuro.com (not a shameless plug for a vendor, but in the past year, these guys have been GREAT, and had the parts available that I needed and I'm just passing them along as a kind gesture). Along with this change, I also -

2) did something different with the servo when I installed it. I'm thinking part of my original issue came about when I was doing the valve cover gasket, and when I removed the 4 bolts holding the servo in, it jumped out... I had not "unwound" it before unbolting it. When I replaced it, I wound it back into the valve train, and I have had acceleration problems ever since (until last night). When I reinstalled it last night, I just put it into the hole, then pushed it down to put it under tension, rather than screwing it in. I would say total travel of the servo motor was approximately 1 1/4" until it was touching the mating surface of the spacer. I then bolted it down while under that tension.

Buttoned it all back up, took it for a test drive, and it worked. HOLY CRAP IT WORKED!!!!!!!!! I can mash the gas starting from a stand still, I can mash the gas and kick in passing gear, I have no hesitation at all under heavy acceleration anymore.

BeemerUser · #8 12-06-2017, 06:28 PM

Is the valvetronic servo you are referring to the big silver soda cans on each side of the valve cover? So to uninstall, unwind it, but to install, mash it down and cinch it with the 4 bolts?

I also have a front oil leak just moist all over in front an below the driver valve cover, but have lots of tailpipe smoke at idle-related you think?

gaffinfool · #9 12-06-2017, 06:56 PM

Yes, the big soda can mounted to the valve cover.

No. If unwind it (dont forget to count the spins) when you uninstall it, you will wind it back in when you reinstall it. If you did like I did and don't unwind, I'm assuming you need to just push it back in and re-tension the intermediate lever springs...

Or that's what I'm assuming worked for me, if it wasn't infact the cheap-o ESS that I also just replaced.

As far as your issue goes, I am going to say, yes. Do you get a HUGE puff of smoke AFTER extended idle? The oil on the front of your engine is more than likely the upper timing chain gasket leaking, and that is causing a vacuum leak, which sucks oil into the intake and burns it..

BeemerUser · #10 12-06-2017, 07:03 PM

Quote:

Originally Posted by gaffinfool

Yes, the big soda can mounted to the valve cover.

No. If unwind it (dont forget to count the spins) when you uninstall it, you will wind it back in when you reinstall it. If you did like I did and don't unwind, I'm assuming you need to just push it back in and re-tension the intermediate lever springs...

Or that's what I'm assuming worked for me, if it wasn't infact the cheap-o ESS that I also just replaced.

As far as your issue goes, I am going to say, yes. Do you get a HUGE puff of smoke AFTER extended idle? The oil on the front of your engine is more than likely the upper timing chain gasket leaking, and that is causing a vacuum leak, which sucks oil into the intake and burns it..

my gas mileage is low so thinking perhaps this is the culprit. is the job tough to change the gasket leaking? thanks

Sponsored Links