[jay-rock]

Just bought an 07 328xi a few weeks ago so doing some preventative maintenance.

I changed the spark plugs and coils a few days ago. It seemed to start fine after doing it. However, today I noticed a rough idle for the 1st 15 to 20 seconds or so after starting. The engine was warm. I had been driving for about 30min before starting it the 2nd time. Didn't notice it on the cold start, though I may not have been paying close attention.

On the 4th (from front) spark plug, there was oil on the old one when I took out. Can oil leak here and be related to this problem? The hole is right where someone could have easily poured oil in when changing the oil (which was done right 4 weeks ago) so is it possible the oil is just left over from sloppy pouring?

If its not the oil issue, I'm concerned I may have bought knock off parts from amazon. Links here...

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Are these prices too good to be legit?

Also, when you turn the battery on, but not the engine, its normal for the "service engine soon" light to be on right? It goes off when I start the engine. So much to learn. This car did not come with a manual to read.

[Mr. Rothstein]

Yes, it's normal for the SES light to be on when you put it in the ignition mode, but don't start the engine. And if the light doesn't come on when the engine is running, then evidently the computer doesn't detect a fault.

The Bosch coils and the NGK spark plugs you bought seem to be legit and should be top notch. I mean, one Bosch coil is about $22, so $128 for six should be pretty legit.

Take the covers off again and see if there's still oil in the cylinder 4. If there is, you might have a leak, probably from the Valvetronic motor gasket because it's right next to it, but it could also be the inside gasket rings of the valve cover gasket are leaking at this particular spot. On the other hand, if the computer isn't telling you there's a code, then all coils and spark plugs should be working perfectly.

By the way, if the oil change was done by a person who knows how the BMW works, then they would never have poured the new oil in the oil top-up opening. When changing the oil, the new oil is always poured into the oil filter opening before installing the new filter. Moreover, even if the person had poured oil into the top-up opening, then they would've not removed the engine cover and it could not have dripped onto the spark plug.

But I am curious, however, why isn't the computer giving you a code that would trigger the SES light.

Having just today replaced my eccentric shaft sensor, the roughness might be due to it having failed. And the computer does not always give you a code when the eccentric shaft sensor has failed. You just learn along the way that it's this.

[jay-rock]

Thanks, Mr. Rothstein

The dealership changed the oil so I'm sure they knew what they were doing and it must not have been from pouring new oil.

I wiped up the oil as best I could when changing the plugs. It was only in that one cylinder. However, ALL the plugs were black at the tips. Burning oil? There is no visible smoke and I don't smell any burning.

If its just a slow leak with the valve cover gaskets, would the computer sense that or would it getting worse for it to sense it?

[Mr. Rothstein]

Originally Posted by jay-rock

Thanks, Mr. Rothstein

The dealership changed the oil so I'm sure they knew what they were doing and it must not have been from pouring new oil.

I wiped up the oil as best I could when changing the plugs. It was only in that one cylinder. However, ALL the plugs were black at the tips. Burning oil? There is no visible smoke and I don't smell any burning.

If its just a slow leak with the valve cover gaskets, would the computer sense that or would it getting worse for it to sense it?

The computer will not sense a leak. The computer will sense a cylinder misfire. As you don't have a cylinder misfire, I would look elsewhere. When a cylinder is misfiring, the car will start shaking on idle and especially on reverse. If it's not doing that, then it's probably not an cylinder misfire.

Also, if the dealership changed the oil, they would've looked at any leaks from any gaskets. At least I would imagine so. What does "the dealership" mean in this case--an official BMW dealership? An unofficial BMW and/or European car dealership? Uncle Sam's car service on the corner of fuck and moron?

Can you explain better what "rough" exactly means in your case?

[jay-rock]

It was an official BMW dealership. That’s where I bought it from. They changed brakes, battery, oil and some other stuff before putting it up for sale. I think they had a note about fixing an oil leak l, but I assumed that was like a leak dripping on the ground.

There is no issue in reverse.

It’s like the car is shaking a little left to right and the car vibrates...like the dash and steering wheel vibrate, then after a 20 seconds or so it smooths out.

[mweisdorfer]

Originally Posted by jay-rock

Just bought an 07 328xi a few weeks ago so doing some preventative maintenance.

I changed the spark plugs and coils a few days ago. It seemed to start fine after doing it. However, today I noticed a rough idle for the 1st 15 to 20 seconds or so after starting. The engine was warm. I had been driving for about 30min before starting it the 2nd time. Didn't notice it on the cold start, though I may not have been paying close attention.

On the 4th (from front) spark plug, there was oil on the old one when I took out. Can oil leak here and be related to this problem? The hole is right where someone could have easily poured oil in when changing the oil (which was done right 4 weeks ago) so is it possible the oil is just left over from sloppy pouring?

If its not the oil issue, I'm concerned I may have bought knock off parts from amazon. Links here...

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Are these prices too good to be legit?

Also, when you turn the battery on, but not the engine, its normal for the "service engine soon" light to be on right? It goes off when I start the engine. So much to learn. This car did not come with a manual to read.

Was the car working just fine before the plug & coil change?

There have been reports, over the years on this forum, about poor quality coils being sold on Amazon as legit. FYI.....

Why not Bosch OEM plugs?

Did you double check all the connections?

Dielectric grease? It should only be on the entry lip of the coils just so they don't heat up & stick to the plug over time? If that got on the top of the plug in some way, that could be your problem.

Did you put a small amount of anti-seize on the plugs?

FCP is a much better place to buy coils & plugs. You get a lifetime warranty.

You may have to start over by buying another set of plugs & coils, if you can't find the source of the problem & the car was working good before the install.

What codes did you get ?

[Bimmer Pleaser]

there should be no oil on spark plug or coil. If there is, replacing/wiping them will not fix the problem. You need to find the source of leak (probably VCG) and fix/replace that.

[jay-rock]

mweisdorfer,

Car seems to be working fine today. Odd.

I used the NGK over Bosch because that seemed to be the consensus on the forums from what I could find. Also, I think BMW is using NGK. The original ones that I took out were NGK.

I did check connections. Did not use dielectric grease. No anti-seize. Heard is wasn't necessary.

There is a way to check codes with no check engine light on? I'll look that up.

[jay-rock]

Bimmer Pleaser,

Should I go ahead and fix this now even though everything seems to be working fine? I wouldn't even know about it had I not changed the plugs (other than the random rough idle on start up which sometimes doesn't happen at all).

I don't have the time to do it anytime soon and would like to put off the $500 or so repair if possible Should I just be glad I found it early when changing the plugs, fix it now to stop it from getting worse and damaging more things?

[mweisdorfer]

Originally Posted by jay-rock

mweisdorfer,

Car seems to be working fine today. Odd.

I used the NGK over Bosch because that seemed to be the consensus on the forums from what I could find. Also, I think BMW is using NGK. The original ones that I took out were NGK.

I did check connections. Did not use dielectric grease. No anti-seize. Heard is wasn't necessary.

There is a way to check codes with no check engine light on? I'll look that up.

If you had the Schwaben/ Foxwell scanner, you could read any codes, even if the check engine light doesn't light up. There are codes that will generate w/ out a check engine light.

Bosch is the OEM provider for e90's in both plugs & coils back in the day. Eldor coils are the latest coils used by BMW. However, they still use Bosch plugs.

The only time I have seen an NKG plug recommended over a Bosch was for tuned 335's, and you have to gap it to something like .22. NKG runs a cooler burning plug is why. It's only recommended if you are tuned and over 400hp.

[Bimmer Pleaser]

Originally Posted by jay-rock

Bimmer Pleaser,

Should I go ahead and fix this now even though everything seems to be working fine? I wouldn't even know about it had I not changed the plugs (other than the random rough idle on start up which sometimes doesn't happen at all).

I don't have the time to do it anytime soon and would like to put off the $500 or so repair if possible Should I just be glad I found it early when changing the plugs, fix it now to stop it from getting worse and damaging more things?

A leaking VCG is not as harmful as OFHG to the engine but it'll keep getting worse and making a mess in your engine bay. At some point you'll have to fix it. $500 to replace is not bad at all.

[jay-rock]

I just looked at the cars CarFax and it says on 03/25/2016 the BMW dealer replaced the Intake manifold gasket and Valve cover.

Would they have replaced the Valve Cover without replacing the VCG? If they did replace the VCG, could it already be leaking again? If the VCG is good, I read somewhere else this could be valve stem seal leak? Plugged crankcase vent?

I really appreciate your help.

I'll probably be taking this to my indy soon, but would like to have some clue as to what is going on first.

[Bimmer Pleaser]

Originally Posted by jay-rock

I just looked at the cars CarFax and it says on 03/25/2016 the BMW dealer replaced the Intake manifold gasket and Valve cover.

Would they have replaced the Valve Cover without replacing the VCG? If they did replace the VCG, could it already be leaking again? If the VCG is good, I read somewhere else this could be valve stem seal leak? Plugged crankcase vent?

I really appreciate your help.

I'll probably be taking this to my indy soon, but would like to have some clue as to what is going on first.

Not unless they are idiots. Unless VC is cracked or warped (very rare) it doesn't need to be replaced, only VCG must be replaced. I think carfax meant VCG replaced even though it says VC.
First VCG usually lastss about 70k for N52 and a little less for turbos. Subsequent VCGs usually last significantly shorter. Also, the more aggressively you drive the more often you need to replace VCG.

It is pretty easy to tell if VCG is leaking; just inspect gasket near the eccentric shaft servo (above cat) or look for oil. Or, wait until car is completely cold, open hood, turn on car and wait a couple of minutes until cat gets hot. If VCG is leaking you'll see smoke coming off cat for a couple of minutes.

[Jai]

I'd be very surprised if they 'forgot' the VCG. You don't do a job like this and forget it... I think.
If it remains I'd just pull out the coils and check if there is oil in one of the holes. If there is you know you should fix it as already said. If not, good.
Then get yourself a code reader that works or build one yourself on your laptop.

[MysticRob]

OP, download the owner's manual from BMW.
Also, if you swapped parts then had a problem (as opposed to having issues both before and after) then you likely either did wrong or put bad parts on the car. Your Amazon parts came from non-OEM resellers, so double check your work, plug gaps, coil wiring, etc. Not too hard to logically troubleshoot issues once you put some brain cells into the task.