[avin83]

Hello,

I purchased 06 323i (100k km or 65k miles) earlier this year and have been enjoying driving this buddy a lot although it is a base model where I live.

I was planning to replace valve cover gasket (using DIY post in this site) due to oil leak but during the disassembling process (which did not went that far - just took out ignition coils) I noticed that few aluminum bolts were broken. I don't have tools to take out the studs of the bolt, so I decided to quit DIY and put everything back as it is.

Now my car has vibrating, thud sound at idle. Sometimes the sound is big enough to vibrate seats and even ceilings (with sudden bumps in RPM). This symptom appears after the car is driven for several minutes. for example when at the redlight at gear (P or R). The sound is almost gone when I put N though.

When I took at the ignition coils, unfortunately, one of ignition's rubber end was ripped off and the end part is stucked in the spark plug. I put it back as it is but I am not sure whether this might be the cause of the problem.

There seems to be several people having this sound issue (especially when they changed VCG) in this forum but I was not able to see resolution...

This is my first BMW and would like to enjoy this car... appreciated for any help!

[avin83]

Bumping up the post... I am still getting the thud sound at idle when the car is heated. Does anyone have experienced this symptom?

[07lilredwagon]

I would go back in and check your work....any time those rubber boots on the coils get a rip in them or tear, it will probably affect the spark getting to the plug efficiently. the spark could "jump" to other metal surfaces and become weak before getting to the plug itself.

Also, be sure the coils are plugged in to the wiring correctly....I always double check that the cam lock on top of the coil locks the plug in properly by pushing the plug as Im closing the cam lock....

You should be experiencing a misfire code if this is the case.....are you? have you had the codes read?

The broken bolts for the valve cover can be taken out after the cover is off. If there is enough bolt to grab they should come right out, as there is no tension on them anymore from the VC. Go slow though when trying to remove them. use WD40 or other penetrating oil. You can use vice grips. twist back and forth slightly at first to be sure the bolt is loose. Since your car is an 06, you probably have the aluminum single use bolts. they are known for breaking. ask your dealer what they recommend. My 07 has regular bolts on the VC.....

good luck with it!

JP

[Gohan335i7]

:d:d☝🏻️

[avin83]

Originally Posted by 07lilredwagon

I would go back in and check your work....any time those rubber boots on the coils get a rip in them or tear, it will probably affect the spark getting to the plug efficiently. the spark could "jump" to other metal surfaces and become weak before getting to the plug itself.

Also, be sure the coils are plugged in to the wiring correctly....I always double check that the cam lock on top of the coil locks the plug in properly by pushing the plug as Im closing the cam lock....

You should be experiencing a misfire code if this is the case.....are you? have you had the codes read?

The broken bolts for the valve cover can be taken out after the cover is off. If there is enough bolt to grab they should come right out, as there is no tension on them anymore from the VC. Go slow though when trying to remove them. use WD40 or other penetrating oil. You can use vice grips. twist back and forth slightly at first to be sure the bolt is loose. Since your car is an 06, you probably have the aluminum single use bolts. they are known for breaking. ask your dealer what they recommend. My 07 has regular bolts on the VC.....

good luck with it!

JP

Thank you for the reply The small yellow engine light came (which stayed on) 3 days ago - the car had vibrating sound with reduced power.

The next day I went to mechanic and they read the OBD - combustion misfire at cylinder 3. As you/myself suspected, it was due to ignition coil with the ripped rubber at the end when I tried to DIY last week.

I haven't had any experience maintaining car before, I let the mechanics do the all the repairs - changing 1 ignition coils, all spark plugs (BOSCH platinum), and VCG (with magnesium gasket with aluminum bolts, eccentric shaft sensor seal) - all cost me around $700 labor + $350 parts in CAD

Labor cost me a lot but they said they had to use special tools to take out broken bolts which took considerable time.

Now car is okay - no more vibrating sounds. Also I noticed the car response better most likely due to new plugs.

Besides the plugs and VCG, the here are the recent changes/repairs that were made from prev owner(starter, rack and pinion, tie rod ends) and at the time of purchase(3 months ago - water pump/themostat, new brakes, new belts and tensioner).

Car looks good now but I am not quite sure whether I should keep this car for a long term because 06' seems to be the first year production car although it has only 66k miles (105000kms). Are there any noticeable thing I need to aware at this mileage without much worries?