[Mwishlist]

Good info, thanks!

[joe__]

has anyone actually fixed this problem (varying 50-100 rpm at idle) by changing spark plugs and coils?

I changed the plugs to see if it would fix this and it has not. I'm debating about going for the coils next. 07 328xi /w 63k.

[07Bimmer328i]

Originally Posted by puhahacj

Thanks for the replies guys. Did I mention that the check engine light is not on? Will misfiring spark plug(s) and/or damaged ignition coil(s) trigger the check engine light to come on? If not, I'm a little surprised that I may need to replace them already.

Dealing with the same thing right now...could be bad coil, spark plug or gasket on the cylinder is leaking oil into the spark plug. Might need a new gasket.

[TittoBlunt]

I had something similar to this for a few months. I would feel a small thump as well. My idle was pretty stable though. If anything, it would change by 25-50 (needle barely moves). I changed spark plugs with no change in idle. But then I changed the coils a few months later and it cleared out the "thumping" and I gain back low end power and gas mileage. The coils weren't throwing any codes too.

[GoRomeo]

Clean and swap your vanos and replace your air filter. So easy to do. Also do a techron bottle. My idle improved a lot since then.

[Cir14]

If it was a bad coil you would know it. I blew #6 awhile back, power will be severely lacking.

[joe__]

Originally Posted by TittoBlunt

I had something similar to this for a few months. I would feel a small thump as well. My idle was pretty stable though. If anything, it would change by 25-50 (needle barely moves). I changed spark plugs with no change in idle. But then I changed the coils a few months later and it cleared out the "thumping" and I gain back low end power and gas mileage. The coils weren't throwing any codes too.

Originally Posted by Cir14

If it was a bad coil you would know it. I blew #6 awhile back, power will be severely lacking.

Seems like it comes down to this... is it possible that the coils are causing a problem even though no code has been thrown? Is this known?

[TeinBMW]

Is your dme up to date?

[Phil325]

Originally Posted by GoRomeo

man sorry to hear you are having such bad experience with your car with only 50k miles... keep us posted.

oh he is not alone. i've had more problems than i can remember since 10k and i'm at 123k now with this engine rattle problem just happening. it's at the dealership now, and i'm waiting to hear the bad news. car wouldn't even start for the service person (battery is less than 2 years old and it was completely dead between the time i parked it at the service lane and talking with the attendant, wth).

it's going to be a long week.

[Phil325]

Originally Posted by Stupenal

Just an update - got the car back after another couple days at the dealership. Here's my cross post from the 1 series board

I look at the service invoice (all no charge thankfully under factory warranty) and their troubleshooting for the rough idle was pretty damn impressive. Here's all the steps they performed (after each step, the invoice documents "No change"):

1. Updated vehicle software.
2. Swapped 6 new ignition coils
3. Inspected spark plugs
4. Replaced eccentric shaft sensor
5. Smoke tested intake for leaks
6. Checked vanos function
7. Checked fuel pressure
8. Tested sample of gasoline and found no water/contaminants
9. Performed ethanol test and found 5% (????)
10. Filled injection flush container with fresh gas and ran through fuel rail
11. Installed 6 new spark plugs
12. Swapped injectors from known good car
13. Checked crankcase ventilation pressure
14. Increased idle speed
15. Performed compression and leakdown test (all cyl within range and good psi and within spec, good to know!)
16. Compared dme status requests to known good car
17. Unplugged MAF sensor
18. Checked cam timing
19. Swapped pre cat 02 sensors from known good car
20. Submitted PUMA case to BMWNA and instructed to try swapping post cat o2 sensors
21. Instructed to replace eccentric shaft.
22. Vehicle operating as designed at this time.

Here's what I learned - South Bay BMW (right down the street from me) has some competent mechanics in that if I were trying to diagnose a rough idle, I wouldve done everything they did. They threw the book at the problem, and if it weren't for BMWNA somehow knowing to check the eccentric shaft itself, I don't know if the problem would've ever been fixed.

Why I'm sharing this with everyone is in the hopes that in the future, if someone else has a rough idle, you now know the 21 different work steps that BMW mechanics perform to try and diagnose the exact problem. Hopefully you don't end up all the way down at #21 because the cost of the eccentric shaft itself is some $600. I don't even want to know how much the labor cost is to replace it. FYI - the sensor itself is also $360. Too bad they didn't leave in the new spark plugs, coil packs, o2 sensors, and injectors. That would've been a nice bonus.

The car is no longer under full warranty, but I still have extended maintenance and CPO. This would've been covered under CPO (I think) but I shudder thinking about what recourse I would've had had the car not been under warranty.

Hope this thread will help someone in the future who has the same symptoms.

wow amazing you got it under warranty...sadly, i may need the same amount of work out of warranty. They said it might be the coils and water pump on mine, but that's without a proper diagnostic. They may keep it overnight

[james520]

http://www.chinasinoy.com/service/ca...ix-it-108.html

[ska///235i]

If you been on here long enough you will know that its the eccentric sensor, bmw techs are no better than a weekend DIYer...they just have all the right tools

[rusty_g80]

If the coil is dead the car would vibrate pretty violently at idle and would be lacking power at higher RPMs. Dead coil would no doubt throw a misfire code. Don't deive too long with bad coil as it will cause catalitic converter to fail. If the vibration is low to moderate I would check Vanos solenoids and eccentric shaft sensor.

[Cir14]

Originally Posted by rusty_g80

If the coil is dead the car would vibrate pretty violently at idle and would be lacking power at higher RPMs. Dead coil would no doubt throw a misfire code. Don't deive too long with bad coil as it will cause catalitic converter to fail. If the vibration is low to moderate I would check Vanos solenoids and eccentric shaft sensor.

Agreed on the bad coil, I can check my paperwork and provide the exact code it would throw. Send me a PM if I forget or cant find this thread again.

I had a vanos solenoid replaced (exhaust i think) ~60-70K and it threw a CEL code and was missing at the higher RPM's.

[GoRomeo]

Me too i have a minor movement on idle at times. I replaced my spark plugs and idle did improve, I still have not changed my coils but would like to know if any coils is worn out ir in fact bad. Is there a way to test these? I dont want to spend $200 dlls on new coils if issue are not the coils.

[konradsa]

Originally Posted by GoRomeo

Me too i have a minor movement on idle at times. I replaced my spark plugs and idle did improve, I still have not changed my coils but would like to know if any coils is worn out ir in fact bad. Is there a way to test these? I dont want to spend $200 dlls on new coils if issue are not the coils.

I also got a minor bit of shaking sometimes, often after cold start, but also notice it sometimes when idling at a traffic light. In general, the idle on my 2008 328i with 45,000 miles is not as smooth anymore as it used to be. When I bought the car with 24,000 miles CPO in 2010, you couldn't even tell if the car was running or not, it was that smooth. Now, there is the slighest bit of vibration sometimes mixing in at idle. It's not a permanent vibration, it's more like a slight vibration that comes every few seconds and then goes away again.

Is that something that could maybe be caused by the spark plugs?

[nadans]

I had the same problem like two months ago. I took it to the dealer, and they reprogrammed the software. After like two days, it started acting up again, so i took it to another dealer, and found out that the oil got into the camshaft eccentric sensor.

[joe__]

Originally Posted by joe__

Seems like it comes down to this... is it possible that the coils are causing a problem even though no code has been thrown? Is this known?

I finally found a coil that was torn, arc marks. After changing it the car runs perfect. Should have done the coils sooner.

[Erodinator]

here is my story:
my car had a loud noise one day while driving and it shut off, it was hard to start back up. Once it did that loud whistling sound was there, kind of like a pulley gone bad. It turns out it was the oil seperator valve (I know there is another name for it too), it's a common problem with E90 and possibly even other BMWs. Once they replaced that, the car was still having codes and was hard to start. Once started it shakes and feels like misfires, the mechanic took it to the dealer and they told him that it's the crankshaft position sensor. I'm getting it replaced in a couple days, I will update to let you all know if that fixes my problem.

Crankshaft Position Sensor problem

Crankshaft Position Sensor was replaced, no more problems.

[KNAQ7]

I had a similar issue to you. I changed out a coil and replaced all 6 plugs and it's running smooth right now. I would also clean out the VANOS solenoids with compressed air or MAF cleaner. Take a look at the engine camshaft sensor and the intake camshaft sensor. Try swapping them out.

[HueyT09]

Had AFE oiled cold air intake for a year. (I do not recommend anybody to put this crap on their car because it makes your ECU throw CEL with P0172 code) So I decided to put back my stock intake.. Once i started up the car, the idle was really rough. It was shaking and vibrating but for only few second... Now this problem persist... every morning I start my car it does it.. anyone here know what it could be ?

TY

[colin_e90]

My car had the same problem and it was two bad ignition coils were bad causing a misfire. You should fix it asap