[ronny214]

So yesterday I was eating Torchy's in Dallas and when I got back to the car and fired it up, discovered something that worried me a little bit. I started my car and was waiting for my passenger to get in. He knows a lot about cars too, as he has mod'ed his MS6 and is a big car fanatic. Upon walking to the car I guess he heard a sound that he wanted to investigate, so I popped my hood.

Apparently, when I rev the engine the rev peaks (it can be as high as 6k RPM or as low as 3k rpm, it just is any rev) and as the revs come back down there is a rattle. We actually took a video that I put on YouTube.

Let me first say that if you listen to this on your phone you MAY not hear the rattle. I can barely hear it and I know others had a hard time hearing it. If on a computer you'll need the volume up or headphones on. After uploading to YouTube I put on some headphones on my computer and it was pretty clear.

The rattle starts around 2-3 seconds, again around 4-5 seconds, again around 9-10, and once more around 16-17 seconds. Each time you'll notice I rev my engine a bit first, and it is as the revs are coming down. This happens consistently, and within the car you can't hear anything.

This may be normal, or something, but I have never noticed before so I just want to be safe.

[mosx]

I have that same "rattle" on my 2009. It only happens sometimes though.

[madmanhiker]

normal

[ronny214]

I did some searching in some past threads and read things like:

* Oil level is low
* valve lifters out of spec

I also read this thread here: http://www.e90post.com/forums/showthread.php?t=13504 where he was saying that the rattle/ticking noise he heard was tied to engine RPM. There is no video that I could see, so not sure if the noise he was experiencing and the noise I was getting are different.

Really want to make sure that there is not a problem in the making here. If need be I can take to the dealer but I just put a JB4 and ER Charge Pipe on, so really hate to have to take all that back off.

[mosx]

Here's another post on the subject:

http://www.n54tech.com/forums/showthread.php?t=12887

[ronny214]

Originally Posted by mosx

Here's another post on the subject:

http://www.n54tech.com/forums/showthread.php?t=12887

Yea I've seen this one too. I noticed it says "cold start". I'll do a cold start again this evening and verify it is still there (since I can only hear it when outside the car), run and get a few logs on my JB4 since I haven't done that yet, and then see if I can hear it after engine warm up.

[ronny214]

So the rattle went from something like in the video where you do not hear it, rev the engine and as it comes back down to idle you briefly hear it, to now I can sit at a stop light with the radio off and the engine up and you can faintly hear the rattle noise. I don't know if this has always been the case or if I'm just now looking for it, but it concerns me some.

I know some people have replied that this is normal, but I'd really like more opinions on the matter. Do others experience this issue and consider it normal as well?

[ronny214]

Originally Posted by M.Saines

It could be a variety of issues. I've seen worn/misaligned idler pulley's, oil level, etc. You should bring it to your local BMW dealer and have them run a full diagnostic along with a a 27-point inspection.

Yea I'm getting to the point where that is my last option. I checked my Oil Level from a cold start and it read Max/OK, drove it around till the engine temp came up to performance to check it again, and it read Max/OK again.

At this point I was kind of grasping at the community one more time for someone to go, "Oh I know exactly what that is!" before I go spend time with the dealer.

Guess I'll arrange for something this week to occur with the dealer if I can get over there on my lunch break.

[ronny214]

Originally Posted by M.Saines

From experience, these issues usually take time to diagnose. I recommend setting up an appointment with your local dealer, and possibly scheduling a loaner. I doubt they'll be able to even read all your faults during your lunch break. Beautiful car by the way!

Yea, I figured that would be the case. I'll probably have to pull the JB4 off the car, which I'm not thrilled about.

Thank you! Those are pics from purchase day, so the dealer had just detailed it for me

[ronny214]

Originally Posted by M.Saines

Definitely remove the jb4. They can redflag your car and/or void your electrical and engine warranty.

Yea, I figured I'd have to do that. Ugh. I have it all nice and zip-tied.

[ronny214]

So I took the car in since the service light came on so I could have my fluids and such topped off. I typically do this stuff myself but since the car is under warranty and BMW gets alerted when the light comes on, I figured it'd be best just to let them take care of it. How bad can it be, right? They give me a loaner for the day and send me on my way.

Fast forward to later that day where I'm told that the tech hears the rattle that I described in this thread. Fast forward to today where they tell me that they are letting an engine specialist look at the car with his "advanced tools" so that he can determine the issue. While I knew there was a rattle and it needed to be addressed, even though most people have said it is normal (doesn't sound normal), I wasn't really prepared for BMW to address the issue just yet. As a result I took the car in with a ER Charge pipe on and a JB4....for normal fluid top-offs and such this wouldn't be a problem, but now I'm worried.

I guess I'll wait to hear back from BMW on Friday to see what they come up with. Hoping that they either don't see the JB4 or they choose to ignore it. In a perfect world they'd over look the JB4, figure out the rattle, and repair it. :-/ Here's to hoping that the dealership here in the D/FW area is as mod-friendly as some people have mentioned in the forums that they can be.

Just my luck

[Sunny D]

Subscribed. I also have a rattle like this I noticed last week. Let us know what happens. Good luck!

[ronny214]

Originally Posted by ry335

Subscribed. I also have a rattle like this I noticed last week. Let us know what happens. Good luck!

Well hopefully regardless of the outcome they'll at least tell me the problem. That way if I do have to address it myself I know where to start. I'm hopeful that ill hear something today, so as soon as I find out ill post it here.

[ronny214]

Ok, I picked the car up from the dealer. Before anyone gets too excited, the rattle/knocking is still there. The dealer told me they ruled out waste gates, solenoids, the VANOS, and a few other things. Since the JB and the Charge Pipe were still on the car I went ahead and picked the car up so that I could put it back to stock...it sounds like they are going to have to tear the engine down to find the cause of the issue and I didn't want BMW HQ asking any additional questions; I want the car to go in, get repaired, and come out.

Here is what the engine tech thinks. He said it is possible that a rod is bent or there is a bad bearing (rod bearing I think he said?). My only thoughts with the rod is that the noise happens off and on, and you don't hear it when the car/engine is under load. If I'm at a stoplight in drive you sometimes hear it, and you hear it more frequently if I'm in park or neutral.

The tech did determine that the noise is coming from what sounds to be underneath the engine. Does anyone have any ideas of what it could be, and how I could test to see? I think that a rod issue is a bit extreme considering the noise started at around 11k-13k and this was pre any after-market mods.

[ronny214]

So just posting a quick update. I took the car to a local BMW meet today since I had it back and I let a e90post member take a look at it and listen to the rattle. Based on experience with this members car, and hearing the issue on mine, it seems that we are back to it being a bad VANOS. It isn't throwing any error codes that I know of, or CEL lights. It amazes me that BMW is having such a hard time pinpointing this issue.

[Sunny D]

Originally Posted by ronny214

So just posting a quick update. I took the car to a local BMW meet today since I had it back and I let a e90post member take a look at it and listen to the rattle. Based on experience with this members car, and hearing the issue on mine, it seems that we are back to it being a bad VANOS. It isn't throwing any error codes that I know of, or CEL lights. It amazes me that BMW is having such a hard time pinpointing this issue.

Interesting, let us know what the dealer finally says.

[ronny214]

Yea ill keep y'all updated. I may check with a local shop here and ask his opinion. There is a guy who used to be a BMW tech and opened his own shop.

[Slops]

Yup would like to know the final outcome as well

[ronny214]

Just an update:

Got a second opinion and it seems that the issue truly is a rod problem. The dealer is going to go ahead and replace the VANOS and solenoids, but it appears to be 100% sure that there is a rod issue. They said if that is the case they'll most likely drop a new engine because with an inline 6 it is hard to determine which is the rod at fault without doing full on compression tests...and they said by that point the costs would be about equal and a new engine would simply be the better choice.

Looks like I'll be stepping out of this with a new VANOS, new solenoids, and a most likely a new engine. *Grabs screwdriver to go de-mod*

[Slops]

Originally Posted by ronny214

Just an update:

Got a second opinion and it seems that the issue truly is a rod problem. The dealer is going to go ahead and replace the VANOS and solenoids, but it appears to be 100% sure that there is a rod issue. They said if that is the case they'll most likely drop a new engine because with an inline 6 it is hard to determine which is the rod at fault without doing full on compression tests...and they said by that point the costs would be about equal and a new engine would simply be the better choice.

Looks like I'll be stepping out of this with a new VANOS, new solenoids, and a most likely a new engine. *Grabs screwdriver to go de-mod*

You better de-mod the shit out of that thing!

[boostd92]

I wouldn't by any means say that this is a common failure, but we've done 3 n55 engines over the last two years at my dealership for rod knock/bearing failure. Consider we service 10's of thousands of cars a year, it's tiny tiny percentage, but we haven't done any other BMW motors for rod knock/bearing issues since the E46 M3 recalls...

[ronny214]

Originally Posted by Slopp

You better de-mod the shit out of that thing!

The only thing on the car is the JB4 and the Charge Pipe.

Yes, I have done some searching and I didn't find many with rod/bearing issues. I guess I just have horrible luck.