Trouble after valvecover replaceme nt

gunner12345 · 03-23-2022, 09:48 AM

i have a 2011 328i xdrive. just replaced the valve cover because of oil leak and the pcv was messed up causing a high pitched screeching sound, did all as instructed to from the video from online. tightened the valvetronic motor up till felt resistance then backed it off as unbolting. all went back together good, now i am having trouble with the car running rough at idle and on acceleration. did the valvetronic reset with the key and acc method. i have noticed that sometimes it will start and run perfect then the next day go back to running rough again , what do you guys think the problem could be any help will be deeply appreciated thanks

gunner12345 · 03-23-2022, 10:27 AM

did have a buddy do a scan the only thing we could see was that it said the valvetronic should read 250 and it was reading 219, what puzzles me is that sometimes it will run perfect and others will start running rough ?

smallseafishie · 03-23-2022, 10:37 AM

I'd venture to say you inadvertently created a vacuum leak. Unplug your MAF to force the car to run open loop and see if it idles well. If it does, then that's likely your issue.

Mike K · 03-23-2022, 10:49 AM

Sorry for your woes. What about those faulty VANOS bolts?

Check my thread below about this VANOS bolts issue. Were yours replaced from the recall or extended warranty?

https://www.e90post.com/forums/showt...ight=whistling

gunner12345 · 03-23-2022, 10:58 AM

i unplugged the maf sensor and it made no difference at all, the maf was not even registering on the scan ? i did happen to break the vacuum line on the back of the valve cover so i put a hose over top of where it broke to piece it back together. do you think this could be the issue?

smallseafishie · 03-25-2022, 10:21 AM

Quote:

Originally Posted by gunner12345

i unplugged the maf sensor and it made no difference at all, the maf was not even registering on the scan ? i did happen to break the vacuum line on the back of the valve cover so i put a hose over top of where it broke to piece it back together. do you think this could be the issue?

For sure. Even the slightest of cracks in the vacuum hoses / system will create instability.

nsjames · 03-25-2022, 11:03 AM

agreed sounds like vacuum leak. Do you have the means to view live data or codes? See what the O2 sensors report, if lean, probably vacuum leak.

3/4 hydraulic suction line fits the quick connects that the corrugated plastic hose is hiding.

cost you about $10 at any local tractor/equipment service place and probably last the life of the vehicle.

do not use heater hose or anything that's not reinforced. It will suck closed.

spcgrye92 · 03-25-2022, 11:26 AM

i had a similar issue. with my 08 328i. every thing went back together okay and upon start up there was a whine that would get louder if you jabbed the throttle. engine ran a bit off at idle as well. I thought i had rolled a gasket or maybe messed up the pcv when cleaning the cover. at any rate it went away after letting it run for a bit and then a short drive.

interestingly though the wine came back for a very short period, like a few days, then went away again.

03-23-2022, 09:48 AM	#1
gunner12345 Registered 0 Rep 4 Posts Drives: 2011 328i xdrive Join Date: Mar 2022 Location: kentucky iTrader: (0)	Trouble after valvecover replaceme nt i have a 2011 328i xdrive. just replaced the valve cover because of oil leak and the pcv was messed up causing a high pitched screeching sound, did all as instructed to from the video from online. tightened the valvetronic motor up till felt resistance then backed it off as unbolting. all went back together good, now i am having trouble with the car running rough at idle and on acceleration. did the valvetronic reset with the key and acc method. i have noticed that sometimes it will start and run perfect then the next day go back to running rough again , what do you guys think the problem could be any help will be deeply appreciated thanks
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03-23-2022, 10:27 AM	#2
gunner12345 Registered 0 Rep 4 Posts Drives: 2011 328i xdrive Join Date: Mar 2022 Location: kentucky iTrader: (0)	did have a buddy do a scan the only thing we could see was that it said the valvetronic should read 250 and it was reading 219, what puzzles me is that sometimes it will run perfect and others will start running rough ?
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03-23-2022, 10:37 AM	#3
smallseafishie Colonel 111 Rep 2,017 Posts Drives: AW 07 e92 335i + AW 11 X5 35d Join Date: Jun 2007 Location: Atlanta GA iTrader: (13) Garage List 2007 E92 335i [0.00]	I'd venture to say you inadvertently created a vacuum leak. Unplug your MAF to force the car to run open loop and see if it idles well. If it does, then that's likely your issue.
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03-23-2022, 10:49 AM	#4
Mike K Lieutenant 332 Rep 401 Posts Drives: 2011 e91 328i RWD Join Date: Jan 2021 Location: Chicago Area iTrader: (0) Garage List 2011 BMW 328i e91 [0.00]	Sorry for your woes. What about those faulty VANOS bolts? Check my thread below about this VANOS bolts issue. Were yours replaced from the recall or extended warranty? https://www.e90post.com/forums/showt...ight=whistling
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03-23-2022, 10:58 AM	#5
gunner12345 Registered 0 Rep 4 Posts Drives: 2011 328i xdrive Join Date: Mar 2022 Location: kentucky iTrader: (0)	i unplugged the maf sensor and it made no difference at all, the maf was not even registering on the scan ? i did happen to break the vacuum line on the back of the valve cover so i put a hose over top of where it broke to piece it back together. do you think this could be the issue?
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03-25-2022, 11:03 AM	#7
nsjames Brigadier General 2443 Rep 4,330 Posts Drives: 08 328xi Touring Join Date: May 2017 Location: ohio iTrader: (0)	agreed sounds like vacuum leak. Do you have the means to view live data or codes? See what the O2 sensors report, if lean, probably vacuum leak. 3/4 hydraulic suction line fits the quick connects that the corrugated plastic hose is hiding. cost you about $10 at any local tractor/equipment service place and probably last the life of the vehicle. do not use heater hose or anything that's not reinforced. It will suck closed.
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03-25-2022, 11:26 AM	#8
spcgrye92 New Member 8 Rep 20 Posts Drives: 2008 328i Coupe 6MT Join Date: Mar 2021 Location: North Carolina iTrader: (0)	i had a similar issue. with my 08 328i. every thing went back together okay and upon start up there was a whine that would get louder if you jabbed the throttle. engine ran a bit off at idle as well. I thought i had rolled a gasket or maybe messed up the pcv when cleaning the cover. at any rate it went away after letting it run for a bit and then a short drive. interestingly though the wine came back for a very short period, like a few days, then went away again.
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