[uncle don]

Bone stock 2007 335i 118k miles little old lady car I just bought this weekend.
All maintenance records well taken care of blah blah. I have noticed when moderately taking off the car was hesitating and surging then once in higher rpms it cleared out and pulled hard and smooth. From a 60mph kick to 100mph zero issues and runs strong and smooth. Now fast forward to tonight I turned the dtc off stopped on a back road and brake torqued it a little the wheels spun for maybe a foot then BAM it ran like crap check engine light came on and code p0303 is what showed when I scanned it.
Now it’s running ruff idle ruff and you can tell maybe on 5 cylinders or so....
I’ve read up a lot on each separate issue I’m having. Are these bucking surging hesitant in low gears connected to the p0303 code that I just now got? Which says #3 misfire.
Last couple days there was zero check light on just had the surging at low gear or two under moderate acceleration.

Any help be appreciated

[uncle don]

Records show new plugs replaced 33,000 miles ago.
Nothing else major has been replaced other than oil belts and filters

[doomangel]

haha you got misfire too.

spark plugs may be an issue from what I've read, then coil pack, then possible injectors.

My injectors were leaking pretty bad at 88k and I was having long cranks and rough idles

[uncle don]

I moved my #3 coil pack around and the code followed it...so I know I need a coil pack now. ill do that this evening. should this fix my bucking surging in lower rpm's when under moderate boost also?
thanks in advance.

[matamua]

Originally Posted by uncle don

I moved my #3 coil pack around and the code followed it...so I know I need a coil pack now. ill do that this evening. should this fix my bucking surging in lower rpm's when under moderate boost also?
thanks in advance.

I'd think so, but you probably also need a walnut blast.

For the time it will take you to do the coils, I'd say it's worth doing plugs too. I've got an 07 335i as well. Just barely did this.

I found plugs from FCP euro at 6 for $32.34–much better than $140 from the dealer or $90 from ECS.

You are right there doing the same work. For an added $30 and 15min you don't have to think about it again.

[uncle don]

UNFORTUNATELY at the moment I don't have a socket to fit the plugs...I tried every mm and 5/8 socket I had lol and I don't have any thin enough to go around the plug...so it wasn't much trouble at all to take it down that far 5 minutes maybe, so I will just get it running hopefully tonight and I will be shopping for new coils and plugs before I put a jb4 tuner on it.

[Maestro]

As it was pointed out, you need to do a walnut blast on the intake. With the car being and 07 like mine, you could have minor vacuum leaks on the intake, recommend replacing the rubber/silicon seal on the intake, replace all the coil packs, not worth just doing one. You can get them on Amazon for $126 for 6 and they are original equipment just do not have the BMW logo, made in the same Bosch factory that make the BMW logo ones.

You also need a special BMW spark plug socket, it is not standard 6 or 12 sided socket.


Before you put tune on it, you should give it a once over and do all the maintenance, like leaking oil seals, for VC and OFH.

[matamua]

Originally Posted by Maestro

As it was pointed out, you need to do a walnut blast on the intake. With the car being and 07 like mine, you could have minor vacuum leaks on the intake, recommend replacing the rubber/silicon seal on the intake, replace all the coil packs, not worth just doing one. You can get them on Amazon for $126 for 6 and they are original equipment just do not have the BMW logo, made in the same Bosch factory that make the BMW logo ones.

You also need a special BMW spark plug socket, it is not standard 6 or 12 sided socket.


Before you put tune on it, you should give it a once over and do all the maintenance, like leaking oil seals, for VC and OFH.

Yeah, I bought the BMS socket on amazon for about $20. Still worth it am for the savings of doing it myself.

[matamua]

Originally Posted by uncle don

UNFORTUNATELY at the moment I don't have a socket to fit the plugs...I tried every mm and 5/8 socket I had lol and I don't have any thin enough to go around the plug...so it wasn't much trouble at all to take it down that far 5 minutes maybe, so I will just get it running hopefully tonight and I will be shopping for new coils and plugs before I put a jb4 tuner on it.

I would strongly consider the walnut blasting. Also, it seems like more folks are doing MHD as opposed to JB4.

[relative4]

The spark plug socket is a standard thin wall 12pt spark plug socket you can get from AutoZone for like $7.

[uncle don]

Originally Posted by relative4

The spark plug socket is a standard thin wall 12pt spark plug socket you can get from AutoZone for like $7.

what size 5/8? or do you have to get a MM?

[uncle don]

Originally Posted by matamua

I would strongly consider the walnut blasting. Also, it seems like more folks are doing MHD as opposed to JB4.

I haven't researched "walnut blast" and have no idea what that means... or how to...
can you briefly explain difference between MHD? and JB4?

[matamua]

Originally Posted by uncle don

I haven't researched "walnut blast" and have no idea what that means... or how to...
can you briefly explain difference between MHD? and JB4?

Walnut blasting refers to using walnut shell media to blast the carbon/oil deposits off of the intake that develop over time with the injection motors. The deposits reduce flow and efficiency. On non-tuned cars, this is supposed to be done about every 60k. On tuned cars, more like 40k.

Jb4 is a boost controller only and something that at is a hard ware install. MHD uses an android phone or tablet to do a custom ECU flash. There's more flexibility and options with MHD. A stage 1+ on pump gas is supposed to net you about 100hp. It's recommended that you upgrade the intercooler and charge pipe for that. Stage 2 goes higher and requires downpipes. Stage 3 gets nuts and you start needing more stuff—gets speedy fast.

The nice thing is that your can change ecu maps pretty quickly, and you can also revert it back to stock. It also has some ability to read data real time and erase some codes.

Some people do MHD and JB4 on the backend.

[matamua]

Originally Posted by uncle don

what size 5/8? or do you have to get a MM?

ATLIN Thin Wall Spark Plug Socket 12-Point, 14-millimeters Compatible with BMW, Nissan, Mini https://www.amazon.com/dp/B01MXJ3X7P..._38bZDb98QW3AC

[uncle don]

awesome info matamua thank you. I will definitely look into MHD now, I like the sound of that. Price comparison?
so on way to work this morning..went to pass a car or two on the interstate and got in throttle easy....and check engine light came on again. now I have P0301, P0300, P0305, P0140 lol....when it rains it pours. I replaced cylinder 2 coil 2 nights ago.... so atleast I didn't get that code ha.

[matamua]

Originally Posted by uncle don

awesome info matamua thank you. I will definitely look into MHD now, I like the sound of that. Price comparison?
so on way to work this morning..went to pass a car or two on the interstate and got in throttle easy....and check engine light came on again. now I have P0301, P0300, P0305, P0140 lol....when it rains it pours. I replaced cylinder 2 coil 2 nights ago.... so atleast I didn't get that code ha.

I'd definitely do all the plugs and coils, making sure that you are using Bosch/Bosch etc. Not supposed to mix/match Bosch and Delphi

[relative4]

Originally Posted by matamua

I'd definitely do all the plugs and coils, making sure that you are using Bosch/Bosch etc. Not supposed to mix/match Bosch and Delphi

Wrong and wrong.
Do not fire the parts cannon on full automatic.
A bunch of coils and/or plugs did not just go bad simultaneously. Find the common cause. Follow the P0140, and walnut blast.
Mixing Bosch and Delphi is not verboten. That is an old wives' tale.

[matamua]

Originally Posted by relative4

Wrong and wrong.
Do not fire the parts cannon on full automatic.
A bunch of coils and/or plugs did not just go bad simultaneously. Find the common cause. Follow the P0140, and walnut blast.
Mixing Bosch and Delphi is not verboten. That is an old wives' tale.

That was a bit salty, though happy to be corrected if and when I'm wrong. My time is valuable to me. If I can spend an extra $50 to eliminate two equally likely possibilities and not tear the car apart again, I'll do that every time.

I don't know for a fact you can't mix/match. Just regurgitating what I've read elsewhere. You could be totally right.

Do think he needs to strongly consider the walnut blast.

[uncle don]

is there an alternative to the walnut blast? do I have to take my intake off and take it somewhere to have that done? can I do it myself? like carb cleaner and a brush etc... surely another way? walnut blast sounds expensive and I have no idea who could do that around local where I live? is the problem.
I think I agree with matamua on atleast replacing the coils and the plugs, as my records show it hasn't had plugs for 33k and never had coils changed. and its not that much more money or effort to do it while im there. no biggie on that.
once that code came on yesterday morning if felt immediately like it was on 2 cylinders, pretty rough if I tried to accelerate.... so if it need a walnut blast, or injectors, or a fuel pump I would think I would have different codes no? I don't know that's why im asking your guys opinions... something electrical instantly go's out...like coil packs, granite I just bought the car and don't have a long history with myself. just what I can read on past maintenance records.
here is a couple of questions im pondering....

1. the battery seems a smidge low maybe because it seems like on these cold days here in Kentucky its straining to start like a slow crank...its been in the low teens in morning when starting. could this trigger the codes Im getting and make it miss all of a sudden? doesn't seem likely but thought I would mention it.
2. could it be for the past few years the lady owned daily driver never drove it hard, or got into boost much etc... and so now I bought it and kinda shocking the system with my taking off hard, 60-120mph pulls, testing its limits is now EXPOSING the weak parts on car that need changing?
3. if I can keep it running smooth long enough I still have the original issue (even when I test drove the car) of it surging and feeling like its suffocating in low gears, seems to clear out once its above 3500 rpms and in drive and then halls azz and pullz hard... now maybe walnut blasting could be a fix for that? dunno.... but once I get all this electrical business fixed I still want it to pull hard from start to stop as I bought this for a performance play toy that I will mod in the future and drag race some for fun. im just trying to get it to run perfect bone stock and take it to track to get some base line numbers....
thank you all for the comments and suggestions please keep them coming I take all of them serious and look into all them.
appreciate you guys helping this old American muscle car guy to understand german engineering and language on these cars. I love them. just have to learn them.

[matamua]

Unlikely to be the battery.

You can do the walnut blast on your own. There are a few DIYs posted using the Harbor Freight media blaster—search around and it'll be pretty easy to find. I considered it, but it seemed like more work than I was interested in when I had someone local who'd do it for $200. At 118k never having had it done, I'd still say that's a good place to start, even if she drove like a granny. I've seen a few people post about doing it with carb cleaner and brushes, but that seems like a messy pain, and they have said as much.

[uncle don]

replaced all plugs and coils last night. test drive proved much smoother, more power, and so far so good no misfires....crossing fingers it stays that way. this is what plugs looked like when pulled....33k miles.

[uncle don]

oem replacement coils and plugs were bosch.