[zenmoused]

Hi guys, I need some help here before I start tearing my engine apart. I have a 2007 328i (auto transmission) with 40k miles on her.

Starting last week, when I press on the gas sometimes the car will shudder and bog down, almost like I'm in too high of a gear. I'm fairly certain it's not a gear thing, because it will happen at any speed. It usually lasts for about 2 seconds, then everything is back to normal. It seems to happen in instances where I need more torque, like going uphill or accelerating quickly.

The first thing I thought is that I drove through a bad thunderstorm the other day (flash flooding and whatnot) and may have sucked some water into the air filter. So I took it apart and replaced the filter- no moisture. I've also filled up the tank with new gas (it was at 1/4 tank before), but to no effect. My next step would be to check the plugs to see if any of them are fouled or wires are loose, but to me it feels like a fuel delivery problem. Do you guys have any thoughts?

[capo1m]

do u have any mods?

[zenmoused]

No mods.

[Gavin@MMW]

Try resetting your transmission,

I beleive its:

But the key in, turn the electronics on - but not the engine
Hold the gas pedal down for 25 seconds - then release
Start the car and the tranny should be reset.


If that doesnt help I would think its the Torgue converter..

[zenmoused]

Originally Posted by Craven 328

Try resetting your transmission

Thanks, I'll try it tonight- is there any indication that the transmission has been reset after doing that procedure?

[Gavin@MMW]

sometimes you hear a slight "click" sometimes you dont.

There is an actual thread on here if you want to search for the way to do it, im pretty sure i said it right though.

[deanmc]

'07 with 40K miles? You're still under warranty and the maintenance plan. Why don't you take it to the dealership?

[e90pilot]

Sounds like detonation. It could be the plugs, injectors, or some sensor. It's really hard to track it down on a modern car. You should have it scanned. It might be throwing a fault that isn't displayed to you.

[5erman]

sounds like a bad fuel pump to me-if it were injectors or misfires youd get a CEL-fuel pump you would not-you would just get intermittenly low amounts of fuel being pumped-hence the bogged down effect

[zenmoused]

Originally Posted by 5erman

sounds like a bad fuel pump to me-if it were injectors or misfires youd get a CEL-fuel pump you would not-you would just get intermittenly low amounts of fuel being pumped-hence the bogged down effect

That was my thought, but with all the talk of fuel pumps going bad on the turbo model I haven't heard of it happening on the 328's. I have an OBD tool- is there special software people use to scan BMW's? On my VW's and Audi's it was VAG-COM.

[zenmoused]

Well tried the transmission reset and it didn't seem to have any effect. This weekend I'm changing the oil so I'll probably take a look at the plugs and wires then. If it's not those I guess I'll bring it in for a diagnosis.

[zenmoused]

Sorry to resurrect this thread, but for anyone who may have the same problem, I think I've isolated it. I put a tank of 89 octane in, as a last-ditch effort before taking it to the dealer, and it went away. So my thinking is that it has to do with ignition rather than fuel delivery or the transmission. I'm going to check the spark plugs in a little and see if that's the cause.

[e90pilot]

Lol you put worse fuel and it went away? Weird. Check the coil packs too. My buddy's 540 started with low rpm shudders before it started misfiring. Turned out to be a dead coil pack. If you get it to throw a check engine light, that will isolate the cylinder then you can move that coil to a different cylinder and see if the error code follows the coil.

[zenmoused]

Good idea. I'll try it with the usual 93 octane with the new plugs and see if it comes back. If it does, the coil packs are my next stop. My theory with the lower octane gas is that it combusts easier than higher octane, so if it's an ignition problem maybe it would go away.

[mike-y]

Originally Posted by zenmoused

My theory with the lower octane gas is that it combusts easier than higher octane, so if it's an ignition problem maybe it would go away.

bingo. could be a coil going out, or some spark plugs going bad.

[5erman]

why dont you take it to the dealer under warranty-am i missing something here? why pull stuff apart and search for a month now when you could have been missing something big that would have been covered. I am at a loss

[TiAg335i]

my 335i has done this maybe 2 or 3 times....very strange...would press on the gas when im in low gear high rpm's and it would not go anywhere for a second or two...

[zenmoused]

Originally Posted by 5erman

why dont you take it to the dealer under warranty-am i missing something here? why pull stuff apart and search for a month now when you could have been missing something big that would have been covered. I am at a loss

I just love BMW so much that I don't want to spend their time/money on warranty claims. Well, and also I bought my car at an insurance auction. It was previously a lease car and the owner dented a couple of fenders and scratched up a door running off into some brush. $500 of repairs later it has a rebuilt title and no warranty.

[jpl73]

Originally Posted by e90pilot

Lol you put worse fuel and it went away? Weird. Check the coil packs too. My buddy's 540 started with low rpm shudders before it started misfiring. Turned out to be a dead coil pack. If you get it to throw a check engine light, that will isolate the cylinder then you can move that coil to a different cylinder and see if the error code follows the coil.

If the problem is the coil packs, what is the norm, to replace only the faulty one or all of them?
I have an appointment this Tuesday at BMW to check out a CEL on my 2008 3.0si (26000 km with no mods). Is seems to be running on 5 cylinders. If the problem is a coil pack should they replace only the fauly one or is it best to replace all of them?
Sorry for the off topic

[e90pilot]

Just replace the bad one. They're kind of expensive to get all of them.
However, there're really easy to change.

[jpl73]

Originally Posted by jpl73

If the problem is the coil packs, what is the norm, to replace only the faulty one or all of them?
I have an appointment this Tuesday at BMW to check out a CEL on my 2008 3.0si (26000 km with no mods). Is seems to be running on 5 cylinders. If the problem is a coil pack should they replace only the fauly one or is it best to replace all of them?
Sorry for the off topic

Update: Eventualy the problem was at one fuel injector. They cleaned it at I was ready I wasn't even charged anything!!
According to BMW manager, fuel of low quality was the reason. When I asked him if i should add a bottle of injector-cleaner in the fuel tank from time to time, he said it is not recommended.
What is your opinion?
Thanks!

[BudVlad]

Every time I brought my car for service to BMW dealer in Ottawa (Canada) they put in injector cleaner. I’m not sure if I should do that with DI.