[ronokenneally]

I’ve read around and looked into the causes for shuddering when I’m driving with WOT with my 335xi (’08), it seems to be one of a few possible things (Spark plugs, coils, ECU map or reset Adaptions, Injectors). I am not getting an codes, only a noticeable shuddering when under moderate to hard acceleration about 2.5-3.5k rpm. So I’m having difficulty identifying what I need to do to solve this.

So far I have;
Reset all adaptions using; ‘Launch Scan Tool’
Changed the spark plugs and coils

What options I think that I have to fix the problem.
1. Buy a BT cable and reset the exact adaptions as per Mr.5’s guide.
2. See if my car has the most up to date BMW flash on the ECU.
3. I was going to wait until after winter but, I’m looking at tuning the car so I was considering JB4 or Proceed, I could do this sooner and use the reset adaptions feature and also see how it behaves with a different ECU map.
4. Buy one injector and swap it between cylinders until I resolve the problem, (this seems to be a bit of a stab in the dark and what if it is two injectors)

Option 3 seems to be one of the best ways to go forward as it is spending money that I would end up spending anyway.

Let me know your thoughts or if I’m wrong or missing anything?

Thanks

[SaviorXi]

I recommend replacing your plugs first. I was shuddering/misfiring from low RPM's and I changed my plugs last weekend and it is smooth sailing for me now.

[CHECKERED]

miles on car?

carbon cleaning ever done?

problem could be dirty vanos solenoids...

[gtaccord]

You need to have you intake valves celaned (aka carbon cleaning). That will most likely take care of the problem.

[ronokenneally]

Originally Posted by SaviorXi

I recommend replacing your plugs first. I was shuddering/misfiring from low RPM's and I changed my plugs last weekend and it is smooth sailing for me now.

I change the Plugs and Coils with no difference.

Originally Posted by CHECKERED

miles on car?

carbon cleaning ever done?


Not as far as I know, I only own the car about 2 months. It's an '08 with 54,000 KM

problem could be dirty vanos solenoids...

Originally Posted by gtaccord

You need to have you intake valves celaned (aka carbon cleaning). That will most likely take care of the problem.

I will look into that, it sounds like that is what I need to do next, I'll look into it. Is cleaning/replacing the vanos solenoid done at the same time?

[iturbo_bmw]

Do you have any way of reading codes? if your having misfires you need to have a way of reading the engine codes so you can find out which cylinder is misfiring and whats going on. if you've already done coil packs and spark plugs, it could be injectors or dirty intake valves. I don't think resetting your adaptations is going to do anything. first thing you need to do is read you codes so you don't randomly replace parts. buy bt cable or get a tune like jb4 or cobb that can read codes. and read this http://www.e90post.com/forums/showthread.php?t=631829

[ronokenneally]

Originally Posted by e92_bmw

Do you have any way of reading codes? if your having misfires you need to have a way of reading the engine codes so you can find out which cylinder is misfiring and whats going on. if you've already done coil packs and spark plugs, it could be injectors or dirty intake valves. I don't think resetting your adaptations is going to do anything. first thing you need to do is read you codes so you don't randomly replace parts. buy bt cable or get a tune like jb4 or cobb that can read codes. and read this http://www.e90post.com/forums/showthread.php?t=631829

I have read the codes using a general scan tool 'Launch Scan Tool x431' it is supposed to be new and a very good tool for all cars (it could still not cover some bmw aspects in comparison with a BT cable). the only code it showed was the exhaust flap that I have disconnected, I have scanned it about 3 times at different stages and had no codes. I will look into that link,

I think there is no harm in cleaning the carbon anyway ( I must search here for it). Changing the coils was a little excessive but they didn't cost me too much. Changing the injectors is probably the last thing I'll do as it is the most expensive.

Thanks

[tphss]

Please update if you do the intake valve cleaning and it helps.

[ronokenneally]

Originally Posted by tphss

Please update if you do the intake valve cleaning and it helps.

I will do, I haven't had a chance to look through that link suggested properly but I was wondering if there was any sort of thread with a record of what people have done, and in what order, since there is quite a few possible problems and money can be spent unnecessarily. If people listed what they did until it was solved, other people could work out the most frequent items causing the problem. I'm just unclear between all the similar problems.

[bimmerdavid]

If you haven't done a valve cleaning yet, I would start there. Even if it doesn't solve this issue, it should be done anyway and will help down the road.

[Okbye2]

I would say its an injector. source: been there done that
i would get a service engine soon light when it was an injector though. did you?

[ronokenneally]

So a bit of an update. Since I've changed the plugs and coils, the shudders have gotten more severe, not more frequent but a harder shudder. While pushing the car hard at that 2500-3500 rpm area, it threw its first code, so I scanned it and I got '29D1 Combustion misfires, cylinder 5'. So I swapped the spark plug from cylinder 5 into cylinder 4 and the coil from cylinder 5 with cylinder 1. took it for a drive again and pushed it on until I got a check engine light again. I got a sever shuddering whenever I gave it any throttle other that to keep it at the same speed, once I turned off the car and started it again it was fine, I scanned it again and got the same code and an additional one saying that there was a misfire with low fuel.

I have some pictures of the old spark plugs, I think they might show signs of the engine running lean, I'll post them in a minute.

Anyone got any thoughts on what path I'm on, injector? or still carbon cleaning?

[ronokenneally]

[themyst]

Those plugs look ok to me, normal electrode wear, but nothing visible that would cause a misfire on its own.

When you swapped coil pack from the misfiring cylinder to a different one, did the misfire follow to the swapped cylinder or does it still persist in the same cyl?

if the misfire followed, you know it's a coil pack (since you already ruled out spark plugs). Bad injectors would cause a SES light and the car would shudder and idle rough on cold start. Bad injectors leak into the cylinder slowly causing the aforementioned condition, they are rarely the cause of a WOT misfire.

What's more interesting is that you have no tune. Hope you get it sorted out.

edit - one last fine detail you may want to consider, when you reinstalled the plugs and coils, did you make sure the coils are properly seated in the cylinder and that the plugs are torqued to 17 lbs? It's worth ruling any and all variables out.

[thatsosm]

I think it was mentioned that failing o2 sensors could have an impact on misfires.

[JDrago1926]

Originally Posted by themyst

Those plugs look ok to me, normal electrode wear, but nothing visible that would cause a misfire on its own.

When you swapped coil pack from the misfiring cylinder to a different one, did the misfire follow to the swapped cylinder or does it still persist in the same cyl?

if the misfire followed, you know it's a coil pack (since you already ruled out spark plugs). Bad injectors would cause a SES light and the car would shudder and idle rough on cold start. Bad injectors leak into the cylinder slowly causing the aforementioned condition, they are rarely the cause of a WOT misfire.

What's more interesting is that you have no tune. Hope you get it sorted out.

edit - one last fine detail you may want to consider, when you reinstalled the plugs and coils, did you make sure the coils are properly seated in the cylinder and that the plugs are torqued to 17 lbs? It's worth ruling any and all variables out.

Would an leaky injector studder at idle? I have no problems other then idle and I have the same studders OP is explaining... changed plugs and coils...

[themyst]

Originally Posted by thatsosm

I think it was mentioned that failing o2 sensors could have an impact on misfires.

failing o2 sensors can cause bank-to-bank AFR imbalances, trimming issues, mixture codes, and from what I have seen, constant E85 use can accelerate their failure. From what I've seen in numerous N54s, I haven't ever seen a sluggish/failing o2 sensor to be the sole cause of misfiring.

Sometimes it can be tune related, sometimes it can be a hardware issue, but the OP has no tune, which is why i'm quite curious.

[ronokenneally]

Originally Posted by themyst

Those plugs look ok to me, normal electrode wear, but nothing visible that would cause a misfire on its own.

When you swapped coil pack from the misfiring cylinder to a different one, did the misfire follow to the swapped cylinder or does it still persist in the same cyl?

if the misfire followed, you know it's a coil pack (since you already ruled out spark plugs). Bad injectors would cause a SES light and the car would shudder and idle rough on cold start. Bad injectors leak into the cylinder slowly causing the aforementioned condition, they are rarely the cause of a WOT misfire.

What's more interesting is that you have no tune. Hope you get it sorted out.

edit - one last fine detail you may want to consider, when you reinstalled the plugs and coils, did you make sure the coils are properly seated in the cylinder and that the plugs are torqued to 17 lbs? It's worth ruling any and all variables out.

I tried to see if the problem followed and it didn't. I used the correct torque, but I didn't visually inspect the seating position of the spark plug, and it is one of the mildly trick onces, so I might take a look at how it sits.

I used 94 oct fuel, not sure if that is the problem but I'll fill up with 91 and see how it gets on.

When you say tune relate your talking about the standard map that is on the ECU? That is why I was thinking of just going and getting JB4 or Procede sooner rather than later, although if it isn't the problem, I'd like to have this fixed before I go after more power.

I decided to start a thread to try and collect peoples experience with shuddering, misfire problems. Not sure if there is something or if people are interested but it might be of use.
http://www.e90post.com/forums/showth...0#post14782340

[ronokenneally]

Tonight I'm planning to run through it with a friend of mine who is a mechanic, starting with a compression test, and using a borescope, and I'll check how that spark plug is seated, and possibly carbon cleaning, if he can get the tool

[themyst]

Originally Posted by ronokenneally

I tried to see if the problem followed and it didn't. I used the correct torque, but I didn't visually inspect the seating position of the spark plug, and it is one of the mildly trick onces, so I might take a look at how it sits.

I used 94 oct fuel, not sure if that is the problem but I'll fill up with 91 and see how it gets on.

When you say tune relate your talking about the standard map that is on the ECU? That is why I was thinking of just going and getting JB4 or Procede sooner rather than later, although if it isn't the problem, I'd like to have this fixed before I go after more power.

I decided to start a thread to try and collect peoples experience with shuddering, misfire problems. Not sure if there is something or if people are interested but it might be of use.
http://www.e90post.com/forums/showth...0#post14782340

Ah, someone with common sense.

Misfires are going to be plugs, coils, or injectors. But your misfire isn't when you cold start the car, so I really do not think it's injectors. I'd also see if you can borrow a BT cable and reset adaptations if at all possible. There is a learned historical knock value that may be out of whack from old plugs, but I seriously doubt it. The 335i stock is far less prone to misfiring from old plugs than tuned.

One of those things that would be better diagnosed in person than over the internet. N54 misfires are annoying little buggers. Hope you get it sorted out so you can enjoy a tune!

[mnetwork]

Did anything ever come of this??