[Rich-]

i have a code P29d0
looks to be a misfire cyl 4?
car seems to run good, the last 2 mornings it has been colder than usual. and upon startup it has a bad miss, and CEL, after a min. or 2 it goes away
plugs, coil, or injector?
previous owner said plugs were done in jan along with walnut blast.
could it be a weak coil? injector?
where are best prices on parts?

if I replace plugs, what should I buy? OEM? I am running cobb stage 1 tune
coils? OEM? or are there aftermarket that are better?

car has 53K and I have a big family vacation in 2 weeks that I need to get this thing taken care of for.

if it is an injector, is It as simple as swapping in a new one and done? or is there more to it?

any help is great, I am new to BMW, but willing to do s much as I can on my own to save costs.

thanks

[335NJ]

Injector is leaking if the misfire only happens on cold starts, search. There's tons of threads about this exact issue.

You should replace the plugs every 20-25k on a tune, but on a stock engine I'd still do them every 35k just because it's so easy to do for peace of mind. Coils should only be replaced if they're faulty, or if you're doing a build that would typically strain older parts.

[TrAcK TRaP]

I would check coil first before touching injectors. injector has to be coded ones replaced. Switch the #4 coil with #5 and see if cyl 4 still misfires. If it jumped to 5 its your coil if stays on 4 it could be your injector like 335NJ says.

[Rich-]

New codes today
p0304
p29d2
p29d0
p29cc

haven't had time to look them all up, but same symptoms

[gabylonfive]

P29D2 -- Misfire Cylinder 6
P29D0 -- Misfire Cylinder 4
P29CC -- Multiple Cylinder Misfires

I always start with checking plugs and going from there. How many miles has the car seen since January (if you decide to believe the previous owner.) I would just swap them out and start fresh for piece of mind if anything. Plugs are cheap and since you are tuned, better to know exactly how far you've gone on your plugs.

If the plug swap doesn't fix it, like the other folks have said swap a coil from a good cylinder to cyl 4 or 6 and see if it follows. If that doesn't fix it, check your plugs in the morning and see if they're wet with fuel. If so, get those injectors replaced.

[Rich-]

car has had 5k miles since jan, 1/3 of them were a cross country trip when I bought the car. tune was removed when I purchased it as it was a 93 tune and here in the Midwest 91 is all we have. I just reinstalled the tune a few weeks ago stage 1 91 octane

[MK335i]

Originally Posted by Rich-

car has had 5k miles since jan, 1/3 of them were a cross country trip when I bought the car. tune was removed when I purchased it as it was a 93 tune and here in the Midwest 91 is all we have. I just reinstalled the tune a few weeks ago stage 1 91 octane

Most likely coils and/or plugs. At this point you should just go through the process of elimination. The fact you are getting multiple misfires I would just buy new plugs (Bosch - cheap on amazon or anywhere else) and then move to coils which are also relatively cheap (250 or so total on Amazon).

I went through the same thing.

[Rich-]

I was just thinking I'll do all plugs and coils and Bosch is best For plugs? Whst part number? Oem replacement?

[335NJ]

Originally Posted by Rich-

I was just thinking I'll do all plugs and coils and Bosch is best For plugs? Whst part number? Oem replacement?

http://www.ecstuning.com/BMW-E90-335...ion/ES2581741/

[Rich-]

Originally Posted by 335NJ

http://www.ecstuning.com/BMW-E90-335...ion/ES2581741/

that is for the kit that is both bosch plugs and coils,... how does that compare to the one that is both genuine BMW parts?
which are also bosch correct?
aside from the extra $100, what is the difference?

[Rich-]

I put in all new plugs and coils today, looks like ill need a new VC gasket also, as it was leaky. I gave the bolts a light snug, in hopes of slowing any seeping until I can get it taken care of.

here are pics of the plugs left to right are the order they came out left being the front of the car.
plugs are were OEM BMW ones, unsure of miles on them 4th and 5th smelled like gas a little

and the coils that came out

I havnt driven the car much, but it fired right off only drove it a few blocks, I cleared codes and reset the ECM with my cobb tuner, (no tune in it now.)
I guess we will see how it goes? if issues persist, next step is injectors? thoughts ?

were there any recall anything on injectors on a 2010 with 55K miles?
if I replace them can I drive the car to get them coded? is coding needed? how can I do coding myself?

[Rich-]

drove the car today, same issues with new plugs and coils

[924er]

If they smell like gas I would replace the injectors. Don't wait on it. Rockauto sells them for 130 a piece. If u wait on it you can thin out your oil and cause a spun rod.

Change your oil after that I sure ur oil has some gas mixed with if already.

Replace your VC gasket and your car should run like new

Good luck

[Rich-]

thanks, is coding needed? I have a big trip next weekend and would like to drive this one. I hate to bite the bullet and let the dealer do it?
what if I don't get it coded? how will it run?

[brosidelong]

Originally Posted by Rich-

thanks, is coding needed? I have a big trip next weekend and would like to drive this one. I hate to bite the bullet and let the dealer do it?
what if I don't get it coded? how will it run?

Coding is needed. The car should still start and run without coding them, but it's going to run rough like it is at the moment.