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Discussion Starter #1
Hi,

I'm new to the forum but hoping one of you may be able to help with my issues!!!

I have a BMW 320i (N43), couple of months ago it started with a slighty lumpy cold start and hesitation for about 10-15 minutes until it had warmed up. Also at this stage it sounded very ticky!!!

I had the timing chain kit replaced (preventative not because of a fault), coil packs, spark plugs and a full major service as well....this was around a month ago.

A few days ago after driving for about 45 minutes the car seemed to lose it power, it would still drive but seemed very flat and very lumpy. Also it seemed to bunny hop down the road if the revs fell below 1500

I had the AA out to the car who scanned the ECU (never had any lights on dash) and the code came up for the Mass Air Flow meter and the NOX sensor which was sulphurised.

Any way, managed to get the car into a BMW dealer who diagnosed the car with the same faults as the AA and changed both Mass Air Flow and NOX sensor, put the car into a "regen mode" and took it for a 30 minute blast down the motorway. As soon as I got the car home it again was lumpy on tickover, sounded very rough and was just not a very happy little motor!!!

The BMW dealer has said that all injectors had tested OK and there is nothing else showing as a fault but obviously there has to be something.

Any help anyone can offer will be much appreciated.

Many thanks


Tim
 

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Check and clean your Vanos solenoids in the first instance...clean them with solvent and switch them round. These can stick causing rough idle, EML, and other issues.

Could well be the dreaded injector issue. Injectors can fail leading to soiled plugs and then the coil packs fail. Thus if this is the case changing the plugs and coils will just cause them to fail again in short order. Given BMW said the injectors are ok but then sent you home with a car running like shit Id choose to believe they are useless.

Could also be a vaccum leak.
 

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Hi,

I'm new to the forum but hoping one of you may be able to help with my issues!!!

I have a BMW 320i (N43), couple of months ago it started with a slighty lumpy cold start and hesitation for about 10-15 minutes until it had warmed up. Also at this stage it sounded very ticky!!!

I had the timing chain kit replaced (preventative not because of a fault), coil packs, spark plugs and a full major service as well....this was around a month ago.

A few days ago after driving for about 45 minutes the car seemed to lose it power, it would still drive but seemed very flat and very lumpy. Also it seemed to bunny hop down the road if the revs fell below 1500

I had the AA out to the car who scanned the ECU (never had any lights on dash) and the code came up for the Mass Air Flow meter and the NOX sensor which was sulphurised.

Any way, managed to get the car into a BMW dealer who diagnosed the car with the same faults as the AA and changed both Mass Air Flow and NOX sensor, put the car into a "regen mode" and took it for a 30 minute blast down the motorway. As soon as I got the car home it again was lumpy on tickover, sounded very rough and was just not a very happy little motor!!!

The BMW dealer has said that all injectors had tested OK and there is nothing else showing as a fault but obviously there has to be something.

Any help anyone can offer will be much appreciated.

Many thanks


Tim
Sorry to hear you having issues with your 320i.
I have owned 320i 18months now and had also had lumpy at cold start issue. But other than that its pretty reliable.

You can ignore the Nox sensor issue as that has no impact. My car has that error code about De-Nox and suggestion is take car for 30min blast. Been doing many motorway blast last 18months but error code will not shift but no issues with engine performance. My friend has a N43 engine with same De-Nox error code and no issues driving. I am guessing N43 owners just have learn to ignore this particular code

I am curious how the dealer gave a thumbs up to all your injector being fine.. was not aware of any test that shows this.

The mass air flow sensor will cause lumpy drive as that controls the air mixture.. if you have access to scanning tool worth reset error code and take another reading.

As for the injector, if the engine is lumpy at cold start but fine after warmed up that may point to wards a leaking injector which was the issue on my car. But that will cause the faulty cylinder to misfire and EML appear with misfire code.
1 way to check is pull out all 4 spark plugs and check if any darker than others. The leaking injector will have obvious darker spark plug.

This thread by BOMBHEAD was helpful for me and saved a few quid.

http://www.bimmerforums.co.uk/forum/f125/success-e92-320i-rough-idle-rich-running-t440746/


You may need to get you hands dirty and do some DIY because if you run to garage every fault the BMW can be expensive.

If worse case its a injector its not hard to replace but your case it maybe the mass air flow sensor.

Keep us updated
 

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Discussion Starter #5
Thank you all for your responses.....

I was thinking maybe a leaky injector but the "test" that BMW said they had done was actually watching the readings that each injector was giving and the fluctuation in these rates. Apparently they are well within range. Again I'm definitely not agreeing with them but don't really want to start spending a 1000+ without being sure.

However I have beenot speaking to a really nice guy this morning that owns an indy garage round the corner from me. He has said that he has 4 or 5 good injectors which he'll put in the car on Wednesday and prove whether it is the injector.

The only other think which I have discovered is that the timing advance appears to be very high......maybe a botched timing chain?????

Thanks again your help is much appreciated
 

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IMHO that BMW 'test' won't show you what's wrong if you have an injector that's leaking. The injector may deliver OK once you're up and running, but the problem is overnight the injector leaks fuel into the cylinder, hence the rough running on cold start until the excess fuel burns off.
 

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I agree with Phil.
When I car had 1 leaking injector the car was misfiring on 1 cylinder if car has been left standing for few hours.
Once the car has been driven for 15min and fuel burned up you would not think anything wrong with the car.

When BMW check the fuel system on a warm engine everything will look normal.

As mentioned you will need to get your hands dirty and check the spark plugs for signs of leaking injector or stand while the garage carries out the repair

I just hope the Indy does not say he has changed all 4 injectors and presents a bill for 4 injectors.
Unless you able to test injectors yourself you at the mercy of really nice guys at a garage who makes a living from your wallet
 

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Discussion Starter #8
I'm gonna follow your advice!!! The car is booked in with the Indy on Wednesday morning and I have parked it up for a couple of days to save any damage. I think when I get home from work in the morning I'll try and get the spark plugs whipped out and see what state they're in.

I will update as soon as possible, thanks for your advice
 

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Discussion Starter #9
Evening All,

Sorry I haven't updated, been trying to get this car sorted......ok heres the update, I've changed all injectors, VANOS solenoids and NOX sensor and still the car is running lumpy at cold. I really have no more ideas on where to go from here......

Any more ideas???????


Thanks in advance

Tim
 

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Evening All,

Sorry I haven't updated, been trying to get this car sorted......ok heres the update, I've changed all injectors, VANOS solenoids and NOX sensor and still the car is running lumpy at cold. I really have no more ideas on where to go from here......

Any more ideas???????


Thanks in advance

Tim
May i ask why you chose to replace all 4 injectors.. did you have error codes for 4 cylinders misfire?
Did you check the plugs for symptoms of leaking injector?

I am guessing you spent £1k+ on repairs since a new Nox sensor cost £300+ but Nox will not effect cylinder misfire
 

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Dear Tim, I am in exactly the same boat as you. I have changed plugs, oil, coil packs, NOX sensor and mine still has a lumpy idle, misfires and sometimes cranks for ages before starting...all worst when the engine is cold. My next job is to tackle the injectors. I know most advise to change all four but as they are £200 each I plan to replace the one/s that are presumably faulty. I will take the plugs out first - I hope to see blackened or petrol smelling plugs on cylinders where injectors may have been leaking. I will follow BOMBHEADS excellent guide. If after replacing injectors and it still doesn't fix it I will look at replacing the high pressure fuel pump as some members say these can play up...

It's really frustrating though as all this 'diagnostics' comes down to guesswork and throwing parts at the car in the hope the problem goes away. Like you I have had no engine management light or fault code saying 'misfire on cylinder x'. After owning this car for 6 months I am really disappointed - I have spent over a grand (so far) trying to get to get to the bottom of this misfiring and the rear suspension creaking. On top of this I suppose I'll just have to live with the juddering clutch. Prior to owning this thing I had an Alfa Romeo 147 JTD for 8 years. From a car and mark that is supposed to be 'unreliable' I never had these sorts of problems - or costs. On any road, it would eat this supposedly 143bhp car for breakfast too.
 

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When i had injector issues the EML light would not appear when slight lumpy.
It was only when i drove the car and 1 cylinder complete misfired under load did the EML light appear an the error code. When it misfired if was clear it was running on 3 of the 4 cylinders.

The N43 HPFP is easy access next to the injectors. You will know its dying when you need long cranks to start the car.

There are so many used for sale on ebay under £100 if needed
 

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Sayekm thanks really appreciate your post.

I think my injectors are worn as my symptoms aren't quite as profound - yet! Mine's a misfire on idle and noticeable driving under a light throttle with the engine spinning at just under 2000rpm. On the spot, if you hold the revs at say 3000rpm you can feel it missing but the inertia created from the increase in engine speed smooths it out so it is less apparent. Strangely the engine doesn't miss under hard acceleration, it's just flat, slow for the revs to build. Obviously it's an injected car and no doubt full of modern emission control systems but throttle response is poor by any standards.

By the sounds of it HPFP is on the way out too! I am going to take your advice and buy an ebay jobbie. Nothing to lose!

Thanks again.

Paul
 

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Sorry hear the issues about your car Paul.
The symptoms you described does not sound like leaking injector so unlikely find a black spark plug.
Leaking injectors flood the cylinder overnight and engine shake really bad and even worse when revved until fuel have been burnt up.

Keep us updated as your solution maybe gold dust for fellow N43 users:thumbsup
 

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Sayekm thanks really appreciate your post.

I think my injectors are worn as my symptoms aren't quite as profound - yet! Mine's a misfire on idle and noticeable driving under a light throttle with the engine spinning at just under 2000rpm. On the spot, if you hold the revs at say 3000rpm you can feel it missing but the inertia created from the increase in engine speed smooths it out so it is less apparent. Strangely the engine doesn't miss under hard acceleration, it's just flat, slow for the revs to build. Obviously it's an injected car and no doubt full of modern emission control systems but throttle response is poor by any standards.

By the sounds of it HPFP is on the way out too! I am going to take your advice and buy an ebay jobbie. Nothing to lose!

Thanks again.

Paul
Just a thought...this does sound a bit like the VANOS solenoid problem but if you have done those it could be your camshaft position sensors or something. To me the symptoms you describe sound like an issue with Valvetronic - either sensors, or maybe the motor? Valvetronic acts as the a throttle basically (the actual throttle is always wide open - but exists for safety via the DSC i think) so when you adjust your throttle pedal you are actually controlling the valve timing directly not the intake of air into the engine...soif it gets stuck or isnt operating across the range you get this rough idle problem and cutting out at low revs perhaps because of a mismatch between the fuel being injected and the actual amount the valves are opening which is ultimately what controls the engine air intake...its a funny system. This could throw off your air fuel mix and/or create problems with compression. Do check for any codes related to this on Carly. Misfire should show up as different codes if at all.


HPFP usually shows up in a long crank to start IIRC.

Given its an N43 though id start with changing all four injectors, check and clean the plugs, check the coils work etc. Then if that doesnt work try the HPFP. But first scan the OBD for codes to get some direction.

In my N52 id be looking at Valvetronic first.
 

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Phototropic thanks for your help.

I had some diagnostics done just after Christmas by a local garage. They said the VANOS solenoids were in 'good condition' - Quite how they came to this conclusion I don't know. Based on the work they did they suggested replacing all four injectors. I say suggested as they couldn't say categorically it would fix the problem so it's all a bit of a gamble and an £1100 at that! I wonder whether too this is just the 'default' diagnostic as injectors are clearly a weak point on these engines...

Maybe though faulty VANOS could be my problem as reading stuff elsewhere these symptoms are pretty much what I am experiencing:

Diagnosing a Failing BMW VANOS System - When to Repair Your VANOS - BimmerHQ - OEM BMW Parts Online Catalog

Your Valvetronic synopsis does sounds really plausible too...are the sensors/motor easy to investigate/replace?

I am going to buy an OBDII reader and closer investigate my fault codes before I go any further. Up until now local garages have checked codes for me and you don't really get the time to study or go through them at length.

Thanks again,

Paul
 

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Discussion Starter #20
Hi All,

Sorry I haven't been around.....very busy with work. Bit of an update for you. I finally manage to rectify to problems I have been having. The culprit was BOSCH spark plugs. I have replaced them with NGK plugs and all symptoms disappeared immediately. The BOSCH plugs were only 2 months old but there you go......surprised??? I was!!!

Anyway, after 4 days of pleasure driving what feels like a new car I've drove to work tonight and the engine management light comes on!!!! I've just code read the car and have one code P0175 Bank 2 sensor 1 too rich. Guess its back to the garage in the morning.
 
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