Bad engine misfire

[zippy320]

Hi guys, the troubles of my car never stops.
It's a 2002 e46 318i automatic with n42 engine.

One day it was fine the next morning it's shudderig and hesitating . It starts up perfectly, but is very under powered and shudders a lot.
I changed all the coils and plugs with new parts and the problems still there .
Used inpa and it said that misfire detection code 274E and misfire detection in cylinder 4. Code 2744.

I know my vulve stem seals need replacement, but it wasn't so bad, I just replaced my fuel pump, the 02 sensors are new but iv removed the cats so the errors been there for years .

I'm stumped . This cars giving me such grief this year.

 

[Peter@AEW]

Check coil packs.

Move coil pack number 1 to misfiring cylinder number 4 and move 4 to 1..
If misfire moves to 1 then it is a coil pack issue.

Could also be plugs depending on age.

 

[zippy320]

Thanks a1exander

I replaced all the coils with new coils and all plugs with new plugs.
Would moving the new parts around still help?

Check coil packs.

Move coil pack number 1 to misfiring cylinder number 4 and move 4 to 1..
If misfire moves to 1 then it is a coil pack issue.

Could also be plugs depending on age.

 

[Sankekur]

.... with n42 engine.....

This might be the cause of your problems....

These motors are known to just start giving problems for no apparent reason, and in some cases to never stop having issues no matter how much you sped and replace.

 

[francoishensen11]

Remove no.4 coil from cylinder,while connected to wiring put in a spark plug and physically check if that cylinder sparks,if it does return coil to cylinder,remove injector rail and turn upwards,have someone crank engine and physically check if no.4 injector is spraying fuel, if not that's obviously your problem,if not do a compression test, if no.4 has bad compression,retest compression this time with vvt unplugged, if compression is good you have a bad vvt motor, if it's the same result (low compression)with vvt unplugged its time to remove the valve cover aka tappet cover and physically check the rockers, lifters and cam condition,while off also check the "third cam" condition of the springs on that unit specifically no.4, might have a bad spring that snapped which in turn caused to knock off one of your rockers from its hydraulic lifter, also if you have pics of the condition of your old plugs especially no.4, a plugs condition can tell alot of what's going on internally.

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[francoishensen11]

@zippy320 keep us posted to your findings.

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[zippy320]

Hi francoishensen11

Thank you so much for your help! very very informative , I really appreciate your help.

I swapped the coils around , checked for spark using one of the old plugs (there was a spark) checked all other coils and plugs for spark, and I found spark. I did replace all coils and plugs with new coils and plugs as soon as this problem came about.

Did not manage to check for fuel , I wasn't sure how to remove the rail to check for fuel and I don't have the correct equipment to test for compression. Also didn't have a chance to remove the tappet cover .

The other items as well are a little out of my league , when it comes to this engine as its my daily car im a little more afraid of causing more damage then there already is (if there is)

I do have the old plug , it had a little oil residue on the threads. Will take a picture and post it up later. ( I assumed this oil was possibly from the leaking valve stem seals?)
The spark plug didn't look bad , nor burnt , bent or worn out.

In my state of panic and sadness, I dropped the car off at BMW pinetown . Its about 5 min from my home so wasn't that far a drive.

Things I noticed were , above certain revs, on a straight the car seems to act normal though a little sluggish. Downhill it goes fine , Going uphill it looses almost all its power, At standstill its terrible, but does not switch off, rev goes as low as 500rpm , Fuel economy has improved? (How I don't know but the economy meter on the cluster shows an improvement by at least 0.5 )
As the revs get higher 3k up it tends to drive normally.

@Sankekur , I don't know , many have told me that this is a bad engine , we had this car since new , I haven't exactly babied it though it isnt driven that hard at all . In 12 years , Its had a few oil leaks, 2 coil issues , a slipped chain (thankfully it was parked and did no damage to the engine ) a VVT motor replaced , this was over and above the normal maintenance like replacing water pumps etc.

Will know by today or Monday what its condition like. Will keep you posted .

*on a side note, the night before , I removed the cubby box and a few panels to reposition the cable of my Ice-link Ipod integration , I had to unhinge and lower the fuse box a little to get the cable through. This couldn't have caused this could it?

 

[francoishensen11]

@zippy320 highly doubt the unhinged fuse box has anything to do with it,when you start the car does it swing different/funny from before the misfire?if it sounded different it's possibly the compression drop you hearing.

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Chweet chweet chweet forgive the weird sound but thats how it's supposed to swing(best spelling sound I could come up with lol) if you were getting something like chweet chweeeeet chweet chweet that's a compression drop you'll be able to hear the difference even on just cranking it and compare to another car(4 cyl) cranking,oil residue on the threads of plugs can't cause that imo cause as long as the head of the plug is fine it should spark, that no.4 plug didn't perhaps look "less used" compared to the other 3 if so it may well be compression related.

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[Maljan]

I had a misfire develop on my 530i. It would come and go, but eventually it had to be looked at. The diagnosis was a leaking head gasket putting water into the #5 cylinder. The head was pulled off and rebuilt. The problem was cured. Unfortunately this was not a cheap repair, about R12K. Lots of gaskets and labour go into it, you see. It may have been caused by an overheating incident that went down, but quite some time elapsed between the two repairs. Not sure if this problem happens on the N42, though.

 

[zippy320]

Hi francoishensen11

When starting the car I had not noticed any new strange noises, starts normally as its always started, one turn of the key for half a second or less and it fires up.

I tried to "hear" the engine , but this has always been a little bit of a rattly engine since new , so I didn't notice any changes.

I did notice a slight suction noise a few times when pressing the accelerator while driving. Im not sure if that could be related? I assumed it was maybe wind noise, it happened a few times but not really much that it caused concern.

Will keep you updated.

@zippy320 highly doubt the unhinged fuse box has anything to do with it,when you start the car does it swing different/funny from before the misfire?if it sounded different it's possibly the compression drop you hearing.

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Chweet chweet chweet forgive the weird sound but thats how it's supposed to swing(best spelling sound I could come up with lol) if you were getting something like chweet chweeeeet chweet chweet that's a compression drop you'll be able to hear the difference even on just cranking it and compare to another car(4 cyl) cranking,oil residue on the threads of plugs can't cause that imo cause as long as the head of the plug is fine it should spark, that no.4 plug didn't perhaps look "less used" compared to the other 3 if so it may well be compression related.

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[ChrisBrand]

Get the codes read. We can speculate all we want

 

[Pho3niX90]

Have a look at this part: http://www.bmwfanatics.co.za/showthread.php?tid=9650

 

[zippy320]

Received a call from BMW , they tell me that its the injector that's faulty , its not spraying fuel , I asked them if they are 100% sure its the injector , they said yes, they swapped it around and the fault follows the injector. Francois you were spot on! Thank you sooo much , your advice was awesome!
Im hoping this fixes the issue though, I hope once replacing the injector nothing else comes up.
What could cause the injector to go? Is it possible that my other injectors are on their way out as well? Can I have them all refurbished?

@chris , I read the codes on my INPA , it said that misfire detection code 274E and misfire detection in cylinder 4. Code 2744.

@Andrew , My car has the N42 engine .Im not sure if the part would apply to my car?

Will keep you guys updated. They tell me that they will need to order the part and I will only have the car back on Tuesday.
Im semi happy and semi worried at the moment. But will hope for the best .

@zippy320 highly doubt the unhinged fuse box has anything to do with it,when you start the car does it swing different/funny from before the misfire?if it sounded different it's possibly the compression drop you hearing.

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Chweet chweet chweet forgive the weird sound but thats how it's supposed to swing(best spelling sound I could come up with lol) if you were getting something like chweet chweeeeet chweet chweet that's a compression drop you'll be able to hear the difference even on just cranking it and compare to another car(4 cyl) cranking,oil residue on the threads of plugs can't cause that imo cause as long as the head of the plug is fine it should spark, that no.4 plug didn't perhaps look "less used" compared to the other 3 if so it may well be compression related.

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[francoishensen11]

@zippy320 glad you're sorted, injectors gets clogged up by dirt in the fuel tank that gets sucked up,if you didn't yet, replace fuel filter when your car returns.

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[ChrisBrand]

Glad its sorted bud!

 

[zippy320]

Thanks Guys

I hope its sorted, Hope they dont have issues after installing the new injector. Will know on Tuesday.
Will keep you updated.

 

[francoishensen11]

That's your problem sorted,just don't forget to replace the fuel filter.

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[zippy320]

Hi Guys! got the car back today! Super excited, it seems to be going well , alot smoother as well, Iv only ever driven it about 10kms or less back home. Thanks for all your assistance!

@francoishensen11 , I replaced the original filter with a bosch filter last year around July , since then iv done less then 5000kms ,"edit" maybe 6 or 7 000 kms, Should I replace it again?

 

[francoishensen11]

Glad it's driving smooth, only reason to change that filter again is if indeed the injector was clogged up with dirt, if it just packed up due to other circumstances you should be ok, if possible ask the fellas at the dealer the reason for that injector failure then go from there.

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On a side note: if you have a regular garage where you fill up with petrol check,if possible when they fill their tanks as the lower their tanks the more chance of that dirt getting sucked up from their tanks into your car.

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[zippy320]

Will ask them, something I noticed today, it takes at least 3 spins before it starts up, it never did this before, before it used to start on the first spin, could this be the filter?

Glad it's driving smooth, only reason to change that filter again is if indeed the injector was clogged up with dirt, if it just packed up due to other circumstances you should be ok, if possible ask the fellas at the dealer the reason for that injector failure then go from there.

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On a side note: if you have a regular garage where you fill up with petrol check,if possible when they fill their tanks as the lower their tanks the more chance of that dirt getting sucked up from their tanks into your car.

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