[Pohsib]

2006 BMW 330i 6MT w Sport Package ~200K miles

After a slight bit of what might be consider "spirited" driving (I don't think I exceeded 5K rpms accelerating or downshifting) my car started a terrible flapping sound. It doesn't do it while idling but it does run rough like a missing cylinder - the whole front end of the car vibrates. Also, when I try to drive and it starts that terrible flappy sound, I can't pull over and get out of the car fast enough to see it there's anything going on in the engine bay. The "flapping" doesn't stop the instant I take it out of gear and pull over.

I had just replaced the radiator with an all aluminum one, a few coolant hoses, the belt, and the tensioner. I had driven the car about 40 miles that day and it ran beautifully. The "flapping" event started that evening after about five minutes of driving and one minute of that spirited driving (if it can be called that.) Since I had purchased new coils and spark plugs, I went ahead changed them out. That did not fix the problem.

I started a list of possible problems in the order that I think could possibly be:

Broken DISA valve
Faulty eccentric shaft sensor
Faulty valvetronic camshaft adjusting unit
Fuel injector issue

Less likely
Timing chain and /or tensioner?

I didn't notice any fuel smell or white smoke. However, I wasn't looking for that during the brief the time I had the engine on. There isn't a metallic or clanging sound from the engine so I'm told that it's unlikely that I broken something in there. There wasn't any oil on the end of the plugs when I pulled them (there was oil around the top of plugs four and five but I'm pretty sure that's because I need to change my valve cover gasket.


How can I sort through the list of possible issues?

I should add too that I have not ruled out possible fuel issues or visually verified the engine mounts. I think those two are unlikely because I changed the engine mounts last year. I get 93 No ethanol gasoline at the same gas station all the time and due to the timing (after "spirited" driving) of the issue I don't think the gasoline is the issue.

[Clammy]

Any codes/ dash warning lights/symbols? Any loss of power?

Cheers!

[Pohsib]

Originally Posted by Clammy

Any codes/ dash warning lights/symbols? Any loss of power?

Cheers!

I don't recall any check engine lights or anything like that. I don't know if it is giving any codes. I do have a Veepeak OBDCheck BLE OBD2 but I have not used it.

I can't say that loss of power was a noticeable characteristic. Certainly not immediately after the "spirited" driving. After that, I didn't really want to drive it anywhere because it sounded so terrible. After I replaced the coils and spark plugs I didn't want to drive it because of that rough idle. I was concerned that I had damaged something internal in the engine. I've since learned that that doesn't seem very likely - based on the sounds it was making and general reliability of the engine. However, I read in another thread that if the DISA was damaged I should not drive anywhere. I had it hauled to the dealership so they could trouble shoot. However, they are super busy due to the holiday and have not had a chance to look at it. If they don't reply today, I may go over there tomorrow and check out a few things myself - at least use my scan tool.

I've seen the term "shudder" in another thread. That might be a better way to describe what's happening some of the time.

[Clammy]

Originally Posted by Pohsib

I don't recall any check engine lights or anything like that. I don't know if it is giving any codes. I do have a Veepeak OBDCheck BLE OBD2 but I have not used it.

I can't say that loss of power was a noticeable characteristic. Certainly not immediately after the "spirited" driving. After that, I didn't really want to drive it anywhere because it sounded so terrible. After I replaced the coils and spark plugs I didn't want to drive it because of that rough idle. I was concerned that I had damaged something internal in the engine. I've since learned that that doesn't seem very likely - based on the sounds it was making and general reliability of the engine. However, I read in another thread that if the DISA was damaged I should not drive anywhere. I had it hauled to the dealership so they could trouble shoot. However, they are super busy due to the holiday and have not had a chance to look at it. If they don't reply today, I may go over there tomorrow and check out a few things myself - at least use my scan tool.

I've seen the term "shudder" in another thread. That might be a better way to describe what's happening some of the time.

So you didn't drive it after changing the coils and spark plugs? It does sound like a misfire to me. I'm no expert, but I doubt you'd hear a bad Disa.

Hopefully the dealership figures it out fast, and it isn't anything serious.

Cheers!

[fastboatster]

Please let us l know what this turns out to be

[Pohsib]

I did not drive it after changing the plugs and coils. I talked to my mechanic yesterday. They’ve been trying to figure it out but have been very busy. Cylinder 1 is misfiring. However, there were no codes. They were asking my about the clutch. They are planning to look at it more on Monday.

[fastboatster]

Originally Posted by Pohsib

I did not drive it after changing the plugs and coils. I talked to my mechanic yesterday. They’ve been trying to figure it out but have been very busy. Cylinder 1 is misfiring. However, there were no codes. They were asking my about the clutch. They are planning to look at it more on Monday.

Got it, thanks for the update. Might be useful for some people, myself including. I might have the same symptoms, I also have a 6mt and like to let the engine clear it's lungs from time to time, and I also don't have any codes. How did your mechanic determine there were misfires?

[Red_Bean_Bun]

Rule out the DISA flaps first.

It’s easier than the other stuff on your list

[fastboatster]

We might be onto something with your suggestion. Come to think of it, many symptoms OP and I have might be caused by DISA valves. I can also hear some clicking sound coming from the intake manifold side of the car. I might have erroneously thought that this is my ac pulley bearing going bad and this sound just appears to be coming from the manifold area. Can you throw in some pointers on how to test DISA valves? Since I have an n51, I got 3 stage manifold just like OP.

[fastboatster]

Originally Posted by Red_Bean_Bun

Rule out the DISA flaps first.

It’s easier than the other stuff on your list

How do you check them? Do you have to remove them from the intake manifold? I don't see anything DISA related in "shadow" code section in Inpa

[Pohsib]

Wouldn’t a DISA malfunction trigger a code? That’s what’s throwing us off. I pulled a P1328 “pending” code when I dropped by but they said they likely induced that trying diagnose the issue.

[fastboatster]

Originally Posted by Pohsib

Wouldn’t a DISA malfunction trigger a code? That’s what’s throwing us off. I pulled a P1328 “pending” code when I dropped by but they said they likely induced that trying diagnose the issue.

I think that somebody said that if you get a disa code, it might be too late. At that point, disa valve parts will fall into the intake manifold and potentially into the engine. So I might just have to pull out the disa valves and see if there’s any play in the valve

[Pohsib]

The shop is saying all signs are pointing to a clogged injector.

[fastboatster]

Originally Posted by Pohsib

The shop is saying all signs are pointing to a clogged injector.

I see. Might be worth to check the disa valves.

[Pohsib]

Originally Posted by fastboatster

I see. Might be worth to check the disa valves.

The plot thickens ...

I asked the shop if I could drive the car approximately ~1 mile to my house. They thought that wouldn't be the issue. I asked specifically if there was any indication if the DISA valve might be an issue. That's when they told me they pulled a DISA valve code(!) I assume this after they did all the other stuff (I'll get a complete list) which did include an inspection of the cylinders. So maybe I got the unicorn DISA valve code without it being "too late"? I only drove the car about 1/2 mile after the problem would've initially came up. I am more inclined to tow the car now that I know they got a DISA valve code.

Do I have one or two DISA valves in my 2006 330i? The shop specified it was the DISA valve on the inside of the intake - the one you have to access from from underneath the intake.

[fastboatster]

Lol, you got a unicorn disa valve code. Anyways, I was told it might be "too latr" because broken DISA parts can easily end up in your engine and end it.
You have 2 disa valves, you can probably pull the one under the intake yourself. Need to check my disa valves, I got very similar symptoms.
Btw, did they rule out the injectors now?

[Pohsib]

Originally Posted by fastboatster

Lol, you got a unicorn disa valve code.
Btw, did they rule out the injectors now?

I don't think so. I can't recall the specifics but I think they swapped injectors in order to confirm that was the issue. I will try to collect a list of everything they did and the order they did it so that the forum has that info.

[Pohsib]

I went by the shop to pay my tab ($200) but didn't get a chance to speak with the service techs. Below is what they typed up in their report. I plan to email them follow up questions. What do you all think I should ask other than the obvious "Which DISA code did you get and is that DISA valve Part#11-61-7-560-538-BOE?"

Shop summary:

Perf testing on the running rough, vibration and cel. Found no misfires codes. Found heave vibration at idle and under load. Found large amount of debris coming from bellhousing area, possible future clutch needed. Found smooth running measure values not good on cylinder 1. Shut off each injector and cylinder 1 did not respond. Tested compression on cylinder 1 and found slightly low at 115 PSI. Perf leak down on cylinder 1 found valves sealing. Activated injector with intake valves open, inspection did not see piston get wet with fuel spray. Verified by comparing with cylinder 2. Cylinder 2 piston did get wet with 2 activations. Recommend new injectors.

[relative4]

Recommend one new injector.

A single-cylinder compression test is meaningless.

[Pohsib]

Originally Posted by relative4

Recommend one new injector.

A single-cylinder compression test is meaningless.

I have purchased six remanufactured injectors. I was debating just buying one but at 200K miles and carbon build up, I thought it'd be best to do all six. Pelican Parts* recommends changing all of them at the same time (of course, right?) I am still on the fence about it - partly due to likely needing to replace DISA#2

From talking with them the previous time, I gathered that they tested compression of the engine itself a couple different ways. At least, that's what I got out of it. That could be something that I clarify with them.


*"If you have an injector giving you a problem, I suggest replacing them in sets of six. This way you maintain an even flow from all the injectors."

https://www.pelicanparts.com/BMW/tec...eplacement.htm

[relative4]

Do the injectors, inspect the DISA fully.

[Pohsib]

Originally Posted by relative4

Do the injectors, inspect the DISA fully.

Do I have to remove the intake manifold to inspect DISA #2?

Or rather ... since I don't have a lift, will I still be able to check that DISA without removing the intake manifold? I really don't want to since I also have to replace the valve cover gasket and the front struts and should do the brake lines. If I do remove the intake manifold what parts would I need to have on hand (other than the crankcase breather hose)? I'm assuming, at minimum, it would involve some intake gaskets.

I have mandatory scheduled "vacation" days coming up, so I could do "all the things" if it's really needed. I'm trying to limit the scope creep of this whole thing.