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Aziz540

E34 540 - left bank not firing

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Hi All, 

 

just wanted to get some some opinions on an issue I’m having with the 540 - any ideas would help! 

 

I was driving, fuelled up, and all of a sudden the car started misfiring badly, and looks like there’s an oil leak on the underside left side too. 

 

The fuel injectors seem to be fine, along with the coils and spark plugs. 

 

The car is misfiring very badly, and checked compression and found these figures: 

 

left bank - 8-10 bar (120-150psi)

right bank - 10-12 (150-180) 

 

Any ideas on the issue?

 

thanks 

 

 

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I would start with checking the engine wiring loom for any damage or age related issues ... 

But sometimes the issue is the DME (ECU) maybe leave the battery off over night and try again. you might get lucky. 

  Have you run out of fuel recently ? This can also cause issue like only a single bank working  on the M60's

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Thank you all for the advise, will check this and report back, I just need some hope that it’s not the end of the car! 

 

Some one advised me it may be the timing chain? 

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On 24/02/2019 at 22:52, Carl-e34 said:

I would start with checking the engine wiring loom for any damage or age related issues ... 

But sometimes the issue is the DME (ECU) maybe leave the battery off over night and try again. you might get lucky. 

  Have you run out of fuel recently ? This can also cause issue like only a single bank working  on the M60's

 

9 hours ago, t.wak said:

Check your cam sensor also.

 

40 minutes ago, Dongiov said:

This car had the same issue, https://www.carandclassic.co.uk/car/C1072363

 

Cause was cylinder wall failure

 

Solution was new engine.

 

 

 

 

Thank you all for the input, really appreciate it - I was hoping it wasnt the end of the engine, will try get ahold of an OBD to see if any codes are thrown for the sensors etc. 

 

 

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Just fired up after leaving the battery disconnected for a couple days - it seemed to run better, not 100%, but better, it then slowly went back to the bad misfire when warming up.. hoping it’s not the cylinder walls - anyone know where I can source an OBD? 

 

Thank you, 

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Hi all, 

 

managed to get ahold of an OBD, the car starts and seems fine, gets a little warm and idles very bad - it’s throwing codes: 

 

Oxygen sensor control #1

 

And “C6” as a code for the scangenie, which I’m not sure as it’s not on the code sheet

 

and finally oxygen sensor 2 

 

this is unexpected, as I changed the two sensors recently, however may be a result of the misfiring damaging them again. 

 

Any ideas would be great, I think I will start at locating and fixing the leak. 

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I think it's time to check al the rubber hoses, check the air intake hose between the TB and air filter for cracks (item 2), clean the idle control valve or replace it,  http://bmwfans.info/parts-catalog/E34-Sedan/Europe/540i-M60/R-M/apr1994/browse/fuel_preparation_system/mass_air_flow_sensor/

 

When did the PCV last get changed?  Item 3. http://bmwfans.info/parts-catalog/E34-Sedan/Europe/540i-M60/R-M/apr1994/browse/engine/intake_manifold_system/

That will defintiely cause poor idle.

 

Re the oxygen sensors, did you use Bosch or some other aftermarket parts?

 

 

 

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2 hours ago, Dongiov said:

I think it's time to check al the rubber hoses, check the air intake hose between the TB and air filter for cracks (item 2), clean the idle control valve or replace it,  http://bmwfans.info/parts-catalog/E34-Sedan/Europe/540i-M60/R-M/apr1994/browse/fuel_preparation_system/mass_air_flow_sensor/

 

When did the PCV last get changed?  Item 3. http://bmwfans.info/parts-catalog/E34-Sedan/Europe/540i-M60/R-M/apr1994/browse/engine/intake_manifold_system/

That will defintiely cause poor idle.

 

Re the oxygen sensors, did you use Bosch or some other aftermarket parts?

 

 

 

 

Geoff is right about the PCV which should be replaced at 80k If these are not replaced the engine will start to run poor and use large amounts of oil ...  If left and left these have been known to explode which is a pain ... 

   I only use BMW or Bosch sensors or you end up chasing the fault  

I will add don't over look items like coil packs failing or breaking down once warm ( most e34's i've seen have their original coil packs.)

  i know the chances of one bank failing is small ... But for poor running these are a good starting point.

If  you find low compression ( if the motor had been standing unused for sometime ?)  with odd bores reading low ...

It's not always kaput ( the rings can stick ) add some redex  into the bore and leave over night ... spin the engine over and check again. 

 

Edit Spin engine over with a cloth over the empty cylinder ... Before retesting.       

 

Edited by Carl-e34

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Hmmm... I would say to the OP there is some very good advice written above. Check vac lines, replace pcv and make sure Bosch sensors are used. Check all that and report back I'd say.....

 

Only other thing as Dongiov mentioned was idle control valve. I've had issues with these before (not on M60 engine) and I cleaned them out with petrol/ brake cleaner and that usually resolved the issue B)

 

However in your particular problem as you say the engine very badly miss fires when up to temp, it's unlikely to be icv. All I remember with them is that it made the engine hunt at idle and not give symtoms like yours, i.e miss fire.... 

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On 26/02/2019 at 09:09, Aziz540 said:

Thank you all for the advise, will check this and report back, I just need some hope that it’s not the end of the car! 

 

Some one advised me it may be the timing chain? 

 

Nope, from the symptoms you have described this has nothing at all to do with timing chain

Edited by boiliebasher

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I had an odd one on my m60 try unplugging the inlet temp sensor as mine would be fine from cold and as it warmed up it would start loosing cylinders on left bank and then shut it down, unplugging the air inlet temp sensor resolved the issue, I replaced sensor and all was good again 

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On 03/03/2019 at 10:04, Dongiov said:

I think it's time to check al the rubber hoses, check the air intake hose between the TB and air filter for cracks (item 2), clean the idle control valve or replace it,  http://bmwfans.info/parts-catalog/E34-Sedan/Europe/540i-M60/R-M/apr1994/browse/fuel_preparation_system/mass_air_flow_sensor/

 

When did the PCV last get changed?  Item 3. http://bmwfans.info/parts-catalog/E34-Sedan/Europe/540i-M60/R-M/apr1994/browse/engine/intake_manifold_system/

That will defintiely cause poor idle.

 

Re the oxygen sensors, did you use Bosch or some other aftermarket parts?

 

 

 

 

On 03/03/2019 at 12:08, Carl-e34 said:

 

Geoff is right about the PCV which should be replaced at 80k If these are not replaced the engine will start to run poor and use large amounts of oil ...  If left and left these have been known to explode which is a pain ... 

   I only use BMW or Bosch sensors or you end up chasing the fault  

I will add don't over look items like coil packs failing or breaking down once warm ( most e34's i've seen have their original coil packs.)

  i know the chances of one bank failing is small ... But for poor running these are a good starting point.

If  you find low compression ( if the motor had been standing unused for sometime ?)  with odd bores reading low ...

It's not always kaput ( the rings can stick ) add some redex  into the bore and leave over night ... spin the engine over and check again. 

 

Edit Spin engine over with a cloth over the empty cylinder ... Before retesting.       

 

 

On 04/03/2019 at 19:51, boiliebasher said:

Hmmm... I would say to the OP there is some very good advice written above. Check vac lines, replace pcv and make sure Bosch sensors are used. Check all that and report back I'd say.....

 

Only other thing as Dongiov mentioned was idle control valve. I've had issues with these before (not on M60 engine) and I cleaned them out with petrol/ brake cleaner and that usually resolved the issue B)

 

However in your particular problem as you say the engine very badly miss fires when up to temp, it's unlikely to be icv. All I remember with them is that it made the engine hunt at idle and not give symtoms like yours, i.e miss fire.... 

 

On 04/03/2019 at 19:54, boiliebasher said:

 

Nope, from the symptoms you have described this has nothing at all to do with timing chain

 

On 19/03/2019 at 09:31, e34m525i said:

I had an odd one on my m60 try unplugging the inlet temp sensor as mine would be fine from cold and as it warmed up it would start loosing cylinders on left bank and then shut it down, unplugging the air inlet temp sensor resolved the issue, I replaced sensor and all was good again 

 

 

Thank you all for the help! - I cannot say how much I appreciate it, was losing hope, done the above, replaced all the intake manifold seals & PCV, along with all the sensors & it’s no longer throwing any codes! 

 

Engine runs ok, but think I need some new cats, - I might go to ‘Hard knocks speed shop’ in Oxford, this will hopefully sort out the slight misfire I currently have, noisy all around the exhaust with a spitting type sound when I rev, . - any where else anyone can recommend?

 

Thanks again all, 

 

 

 

 

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Hi People, 

 

hope all is well, 

 

just writing back in regards to this issue! 

 

I thought I had solved it... but after a few nice drives i am back with one bank still not firing... 

 

i have replaced cam sensor, intake temp sensor, idle control valve, throttle positioning sensor,  PCV, and every seal on the air intake/ intake manifold and still no luck - when I replaced the o2 sensors with Bosch it was running fine.. then it warms up, still fine.. until I push it a little, then starts to misfire and when accelerating feels lumpy and gurgly, I check and the one bank (passenger side) is not firing. 

 

I then disconnected my battery and after 20 mins or so started it up and everything was fine for the drive home, until again I pushed it a little and one bank goes, this in turn is ruining my o2 sensors because of the fuel and causing a code to be thrown on the #1 passenger side, I’m on my second set. 

 

My last hope is to gain some insight from you all, as I believe it may be the ecu? 

 

Thank you, 

 

 

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Just another note: I removed my cats as I ruined a new aftermarket set because of the one bank not firing- so can rule that out - figured I’d solve the issue before thinking about new ones.

 

thanks 

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On 27/05/2019 at 17:32, Dongiov said:

Fuel injectors blocked? I have a set of working Lucas injectors if you want to change yours over? 

 

On 24/05/2019 at 19:41, greenelekta said:

Fuel pressure? Filters or fuel pump might be worth a look

 

 

Thank you all for the help, 

 

sadly still getting these issues, managed to change the fuel filter and new set of injectors (changed the fuel pump a couple years back) 

 

same issue, no noticeable difference to idle when removing the left side ignition plugs. 

 

Any additional thoughts would be much appreciated! - really unsure which direction to look into next.. 

 

also is it normal that engine cuts off when removing MAF sensor? It does this only when the misfire occurs. Thanks,

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Maybe an ECU swap?

 

https://www.ebay.co.uk/itm/BMW-E34-E31-E38-M60-V8-Engine-Control-Unit-ECU-1744605/290754991456?hash=item43b2591560:g:v1sAAOSw43pckpv5

 

I read on the forum below: 

 

Also.. I may have to unplug the o2 sensors? This would make it run closed loop correct? And this way I can see if it is the o2 sensor/lambda control as these are the codes I’m getting. 

 

Edited by Aziz540
Add info

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