[07_335i_AW]

Apparently, my car threw a code for injectors. Hopefully that is all it is. Gotta call the dealership first thing in the morning since they didn't call me today as they said.

[E-9-D]

I experienced the same issue w/ my 330. It happens between gears 1 & 2 if I hit it hard and drop the clutch — my theory has been that it is the result of a stock clutch delay valve. I got a service light this weekend and they said there is a cam issue. We'll see!!!

[austinla335d]

you can read my post- I had the similar issue with my 07 335, also cpo. I had the entire fuel system replaced, new valve cover, new battery, etc, and then they found out pins in my ECU were broken due to the previous owner putting an aftermarket tune on the car. Just a thought, but you should ask that they certify that the car wasn't chipped/tuned before you bought it.

[Potty_Pants]

my car was purchased new... no piggy on my car

[sonorous]

Originally Posted by Nex054

However, I have begun to experience this very strange jerking feeling under hard acceleration. It only seems to happen in higher gears at lower speeds (low-ish RPM). For example, on the highway around 30-40mph in 4th gear mash the throttle and as the RPMs rise past 3-4k there are tiny hiccups in the power delivery that cause a jerking sensation. It doesn't always at the same RPM, and is in no way consistant.

I finally found the right keywords to search for to find this thread and resurrect it. I have the exact same problem on a 2007 335i 6MT. Has anyone found a remedy for this? I recently had the HPFP recall along with all injectors pulled and scanned but not replaced. I had the issue prior and no change after. Anyone?

[BTTGMan]

sounds like injectors but what do i know? my car was driving great but dealership did a premptive HPFP replacement. when they did it they ended up replacing half my injectors. dealer said injector issues commonly tied to HPFP. have them re-scan the injectors.

[IN54NITY]

Originally Posted by Alex D

Dan from Dinan sayds he would bet it is the detonation/knocking sensors intevening. In an a related thread on bimmerforums Shiv from Vishnu says he also thinks that the knock sensoring system is pulling back timing.

Problem being that these N54 engines (same with like our Saab turbo) do not have real knock sensors, but actually measure ionization of the combustion as it occurs on firing the intake charge. How they do it nobody has ever been able to explain to me. I don't think there are any actual sensors.

I think I remember from a discussion on the Saab forum that in our Saab turbo engine the spark plug is actually the sensing unit .... somthing about the resistance of the current flowing through the plug during ignition measuring ionization and informing the computer of impeding detonation ... I think ...

Subscribed.

I've had the same experience, only at track though, with a well warmed engine and transmission. Especially happens to me in 3rd at > 4500 rpms, but I've experienced in 2nd with even higher RPMs and 4th as well in lower RPMs, so I think it's fuel or spark related. Felt the issue with 91 oct, 93 oct, ~but~ not 100 oct, so you could be on to something there with the knock sensors.

Edit: No codes thrown either.

[cstraface]

2007 335xi 6MT - same issue and was most noticeable with a JB installed (the original). Eventually led to cylinder 1 misfire and limp mode. Have since pulled the JB (about 2 months ago now) but still experience the issue, but to a lesser degree.

Dealer could not replicate...

[sonorous]

Originally Posted by BTTGMan

sounds like injectors but what do i know? my car was driving great but dealership did a premptive HPFP replacement. when they did it they ended up replacing half my injectors. dealer said injector issues commonly tied to HPFP. have them re-scan the injectors.

I agree on the injectors. I am thinking of putting in a bottle of FI cleaner just for the heck of it.

However, I don't see any value in trying to get them to rescan the injectors. They are only scanning the bar code to see if the S/N falls in the range of the known problematic and therefore recalled units. I was told I had no such injectors in my car. I kind of wanted them to tell me they were all bad and replaced.

[sonorous]

So I dumped a bottle of Chevron FI cleaner in yesterday with a fresh tank of Shell 93. We will see if it changes anything. Anyone else with this issue? It is nice to know I am not alone but eventually somebody has got to find a solution...

[BTTGMan]

Originally Posted by sonorous

So I dumped a bottle of Chevron FI cleaner in yesterday with a fresh tank of Shell 93. We will see if it changes anything. Anyone else with this issue? It is nice to know I am not alone but eventually somebody has got to find a solution...

fwiw i've heard that injector cleaner is not designed for piezo electric injectors, and that by and large it's either a waste, or a no-no, for 335s. i'm not sure this is settled fact, just something i've heard a few times.

[sonorous]

Originally Posted by BTTGMan

fwiw i've heard that injector cleaner is not designed for piezo electric injectors, and that by and large it's either a waste, or a no-no, for 335s. i'm not sure this is settled fact, just something i've heard a few times.

I read a ton of posts on the subject as well. From that I derived that it would not hurt anything. If I am wrong, I guess we will find out...

[cstraface]

Originally Posted by sonorous

If I am wrong, I guess we will find out...

+1

[sonorous]

Originally Posted by sonorous

So I dumped a bottle of Chevron FI cleaner in yesterday with a fresh tank of Shell 93. We will see if it changes anything. Anyone else with this issue? It is nice to know I am not alone but eventually somebody has got to find a solution...

Well the Chevron did not seem to do anything which I kind of expected. It would be really nice to solve this issue...

[AaronMG]

I experienced similar situation recently. Took it to the shop and they replaced injectors. I couldn't replicate the issue on command, but they should definitely be able to read the codes it's throwing.

[sonorous]

Originally Posted by AaronMG

I experienced similar situation recently. Took it to the shop and they replaced injectors. I couldn't replicate the issue on command, but they should definitely be able to read the codes it's throwing.

Interesting... There is something about the issue that seems like it is injector related. The only problem for me is that I am not throwing any codes. Without codes and the fact that it is hard to reproduce makes it tough to get a dealership to diagnose the issue...

[RoundelM3]

Any updates on this? I'm experiencing this same thing, with about 30K miles on my '07 E92. I had the software updated and the latest pump installed and still get the intermittent "hiccup". I have Dinan S2 software, so I'm particularly interested in what Dinan has to say.

[Potty_Pants]

well it came back for my car... seems to be warm weather related.

dinan had plugs replated on cars exhibiting this problem and it didnt fix it.
and that info was from 6 months ago.

ppp

[RoundelM3]

Anything new from anyone who's posted here?

[bucktown]

carbon buildup.....its becoming a well known issue. after replacing injectors and various other trouble shooting diagnosis, i actually got a new engine under warranty and it (surprise surprise) went away.

theres been a few comprehensive threads on the subject, just do a search for 'valve cleaning' or 'carbon buildup'. that will give you guys with this issue some direction as far as cause, solution and keeping it from happening again.

[XS222]

spark plugs

[galahad05]

Yes, I'm getting this sometimes as well. And I just went through new injector/HPFP replacement (the recall campaign), so it's unlikely to be them.

I bet it's either the plugs or the oil-crud/carbon on the intake valves.

Carbon there could introduce hot spots in the combustion chamber....which would cause pre-ignition (detonation), especially under load.


Also, someone mentioned that our cars don't have regular knock sensors? The only other way I know of for an engine computer to reliably and quickly measure for detonation is through the spark plugs themselves. Measure the "difficulty" (resistance and voltage drop) in sparking the gap on a plug, and you can find out a number of things about the conditions in the combustion chamber. Especially if an uncontrolled detonation is occurring--it's much much harder to light a plug under those conditions.