BMW E90 Diesel - Running on 3 Cyclinders

[Br4d]

Hello,

As title says, BMW 320D E90 seemed to be running rough intermittently, and now it seems like its definitely running with 1 cylinder down.

Car still drives but not properly and when idle the car vibrates a lot more than usual due to the imbalance caused by it running on 3 cylinders.

Had a look around but any ideas on what it could be? Theres no smoke, the 3 cylinders which are running are running fine (No other performance issues)

Thanks!

 

[Br4d]

Theres no noise of banging from the swirl flap being inside the cylinder so i've kinda ruled that out, other than the vibration on idle and the performance issue the car sounds the same and is relatively normal.

Thats the thing... There are no lights or any warnings on the iDrive system at all. System check comes back as 'OK' :S

 

[Br4d]

idrive and a diagnostic plug in are 2 completely different things that look at completely different areas of the car...

But wouldn't an error like this throw up a Engine management light or something?

So what your saying is even without any warning/Engine management light there still may be faults listed in the diagnostic system which can only be viewed by plugging in a diagnostic kit?

 

[Br4d]

Yes pretty much, your iDrive is designed to throw up a fault when things get real serious, at the moment your car is is a bit messed up, but it isn't serious and it isn't enough of an issue yet.

I bet you have a couple of codes in your car that need pulling.

Regarding the engine management light, these lights have preset criteria that has to be met to throw up the light. Eg for an EML to come on due to an emmisisons issue, a normal EGR filters 15g of crap, the EML comes on when the EGR starts filtering less than 5g of crap and a code is storedwhen the car filters less than 10g of crap. Your car currently may only filter 7g of crap and the EML light will not come on either, however a code will be stored.

You may notice the car smoking more when booting it, and you will never know the cause unless your EML comes on or you plug it in to get that code. So you either wait for it to get properly knackered, or you look now..

Ahh, Cheers for that mate.

ill have to get it checked ASAP, But going from what i told you what would you say it is/sounds like?

 

[Br4d]

Injector or flywheel would make it shake loads?

I Thought it was a Flywheel at first when it was off and on randomly, but now its running bad constantly its definitely running on 3 Cylinders,
I think its an Injector too...

 

[Br4d]

Anyone else have any idea what they think it might be?

 

[Br4d]

Are you sure it's running on 3 cylinders and not the balance shaft woodruf key? That would cause a similar experience. That, and running on 3 cyclinders would produce excess smoke and sever lack of power. The balance shaft was prone to going bye bye on the M47 units, not sure about the E90 variant.

would that give you lack of performance?

Theres no smoke and there is a servere lack of power. i think the reason for the no smoke is that the injector may be blocked and not using any fuel hence the no excess fuel to be burnt making no smoke.

 

[Br4d]

Update:

Had the BMW Put on a Diagnostic machine, All results came back as normal with no Faults listed.

Just to recap, other than it running rough on idle there is definitely a performance issue and the economy is definitely being affected, but there is still no smoke or RPM Variation. Seems to sit nicely at 900rpm ish on idle. and doesn't stutter while being rev'ed ether...

Any other suggestions? :S

 

[Br4d]

Under warranty? Stamp your foot and tell them to do their job?

Unfortunately its an 2008 so its out of warranty.

EGR? Air leak?

Took the EGR out and Cleaned it, after seeing some of the really blocked ones online i was expecting the worse but it was super clean. Only had a light layer of dust which i cleaned anyway. Had it checked for an Air Leak too and there was no problems there.

My guess would be an injector either blocked or the mechanical side of it has failed which may explain the lack of fault code . Does it have a DPF ? Could explain the lack of smoke even if the engine is chucking it out.

Did BMW not have any other suggestions ? or was it just a generic fault reader used ?

It was just an AA Crypton Diagnostic Kit. The Injector seems like the cause. Im not sure if it has or not. its the E90 with the newer engine (07 onwards with the straight out the back exhaust instead of the older turnt down one) if that makes any difference?

Thanks for the Suggestions so far guys, Anymore would be appreciated!

 

[Br4d]

I'm so confused with this thread.

In the last 4 days you could have just had the codes read and have it sorted by now.

Why are you playing this guessing game ?!

Get a proper diagnostic computer onto it FFS!

Ive had it read, There isn't any fault codes. Hence the guessing game!

 

[Br4d]

Diagnostic equipment does not just read fault codes!

It was done by the AA, There machine can do basic diagnostics and read fault codes and none were shown.

We pulled off the MAF and a fault was on there for the MAF so we cleared that. so it defo can read codes but 100% none are on there.

 

[Br4d]

You are a lost cause, there is more to diagnostics than reading the codes it is not a magic problem solver the diagnostics give you data with needs to be interpreted by someone who knows how to relate the data.

A cheap or generic reader (as the AA have used) will give basic information only, the manufacturer specific diagnostic equipment will go into a lot more depth. Get it to BMW or a reputable specialist who isn't a moron.

thats the key. get way more info from the manufacturer diag computer

I'll put it into a BMW Specialist ASAP then, Thought any machine would be able to read all the faults, but ill get a BMW Specialist to diagnose it, Cheers.

 

[Br4d]

Update:

Been into a BMW Specialist with all the correct equipment, he spent 5 hours diagnosing it and could not find anything wrong with it. He seems to think something's come adrift but he has no clue what is it.

So I'm completely confused. And have no idea what to do next?
Any advice?

 

[Br4d]

Take it to somebody who knows what they are doing not a garage who knows how to put a sign on the door saying 'BMW specialist'.

Is it vibrating significantly? Every 320d, mostly new or nearly new, that I have driven has a vibration at idle...

He does know what his talking about and theres nothing electronically wrong with it hence no codes. He checked all the injectors and all the engine checks using the software and there defo nothing wrong with the actual running on the engine.

I know your trying to help but yes it is vibrating significantly. ive had the car for a while and its only just started doing it and since its done it it seems to Rev like its lumpy/Running rough. There is a lack of power. Sounds a lot louder / vibrates and the MPG is seriously reduced. There is 100% Something wrong with it but if something has mechanically broke the computer wont know so i guessing its something like the Rear Timing chain which are quite prone to Failure on the late 2007 onward E90 Engine (177Bhp Version)

 

[Br4d]

Take it to a BMW dealer, they will find out what is wrong with it. The garage you took the car to haven't done anything more than plug a computer in, your car needs a proper diagnostic check.

He's got the proper BMW Equipment, there is nothing electronically wrong (Hence a diagnostic kit CAN'T find any problems - all the data from the sensors are normal) so the only way to diagnose it is to suspect something and looking for that part and check that it's 'Mechanically' working which is expensive if you don't have any clue, so I want to narrow it done to more or less a specific part/area so that I can get that checked instead of just throwing money on looking at parts which dont even fit the symptoms.

 

[Br4d]

Got it sorted. Was the Dual Mass Flywheel, Got it replaced and its running sweet now! Finally!