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B21playa

Rough m5

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Try the vanos test again when hot and raise the revs a few hundred more RPM (with the throttle pedal) and see if it then passes. The test is a bit of a blunt instrument to be honest. I suspect it is only out a tiny amount and may well complete the test routine with a few more revs.

 

If it still fails then do the vanos solenoid clean/service as detailed in great depth on m5board. There is much talk of replacing all four cam position sensors if they haven't been done before as well. BMW updated the sensors and apparently the new ones are more reliable. I would do the solenoids first though and see how things go, don't just fire parts at it as that is big money on these. Ger did a thread where he identified the sensor part codes and got real parts cheaper than from the dealers.

 

Should you find yourself doing valve cover gaskets then you are only minutes away from being able to check the cam timing. Some are a little out with age. I'm not convinced any of the above will account for a misfire, that is more likely plug/coil or injector related. That isn't certain, but it is easier to swap plugs and coils around while looking at cylinder balance/roughness graphs than strip the top down. :) Fuel pressure issues can also cause the leanest running cylinders to start to fluff when things are borderline. I would start with the simple stuff before tearing it apart.

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From the OP it sounds like you reset the adaptations/fuel trims too? If so take it for a drive and see what rough running is like after.

 

How old's the fuel in it?

 

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1 hour ago, THe39M5 said:

Try the vanos test again when hot and raise the revs a few hundred more RPM (with the throttle pedal) and see if it then passes. The test is a bit of a blunt instrument to be honest. I suspect it is only out a tiny amount and may well complete the test routine with a few more revs.

 

If it still fails then do the vanos solenoid clean/service as detailed in great depth on m5board. There is much talk of replacing all four cam position sensors if they haven't been done before as well. BMW updated the sensors and apparently the new ones are more reliable. I would do the solenoids first though and see how things go, don't just fire parts at it as that is big money on these. Ger did a thread where he identified the sensor part codes and got real parts cheaper than from the dealers.

 

Should you find yourself doing valve cover gaskets then you are only minutes away from being able to check the cam timing. Some are a little out with age. I'm not convinced any of the above will account for a misfire, that is more likely plug/coil or injector related. That isn't certain, but it is easier to swap plugs and coils around while looking at cylinder balance/roughness graphs than strip the top down. :) Fuel pressure issues can also cause the leanest running cylinders to start to fluff when things are borderline. I would start with the simple stuff before tearing it apart.

 

Thanks for that, will try it again

 

Be interested to see the thread on parts cheaper than the dealers if you have the link

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Just took out bank 1 spark plugs and noticed the coils are dated 99, so must be originals. Nearly 20yrs and 144k on them, wondering whether to change them while I’ve got them off.

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Coils are long lasting and don't come up as an issue very often from what I have read over the years. I certainly wouldn't replace the whole lot to see if it fixes something. First step is to find the rough running / cylinder imbalance feature on ISTA (or indeed INPA has it and is a doddle to use). Get you car warm and missing and see if there is an obvious imbalance. If there is then swap that coil to one far away in the firing order. If the roughness moves you have found the problem. If it doesn't and you have new plugs fitted then you need to look further.

 

How did the plugs look? This engine does appreciate fresh ones, it might just be as simple as that.

 

Look at 'ger's M5' thread post 183 on m5board where he went through how he found what appear to be equivalent cam position sensors. Was a while ago but may still be useful.

 

How many miles have you done since resetting the adaptations? If it is less than a couple of hundred they may not be fully settled yet and you are chasing a non-existent problem, with luck!

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10 hours ago, THe39M5 said:

Coils are long lasting and don't come up as an issue very often from what I have read over the years. I certainly wouldn't replace the whole lot to see if it fixes something. First step is to find the rough running / cylinder imbalance feature on ISTA (or indeed INPA has it and is a doddle to use). Get you car warm and missing and see if there is an obvious imbalance. If there is then swap that coil to one far away in the firing order. If the roughness moves you have found the problem. If it doesn't and you have new plugs fitted then you need to look further.

 

How did the plugs look? This engine does appreciate fresh ones, it might just be as simple as that.

 

Look at 'ger's M5' thread post 183 on m5board where he went through how he found what appear to be equivalent cam position sensors. Was a while ago but may still be useful.

 

How many miles have you done since resetting the adaptations? If it is less than a couple of hundred they may not be fully settled yet and you are chasing a non-existent problem, with luck!

Thanks

 

i’ll stick coils back in and see how it goes. Probably done 40-50 miles max since resetting adaptations.

 

I found rough running in ista but very hard to tell as numbers change so quickly. I’ll take pics of plugs and upload them later

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15 hours ago, THe39M5 said:

Coils are long lasting and don't come up as an issue very often from what I have read over the years. I certainly wouldn't replace the whole lot to see if it fixes something. First step is to find the rough running / cylinder imbalance feature on ISTA (or indeed INPA has it and is a doddle to use). Get you car warm and missing and see if there is an obvious imbalance. If there is then swap that coil to one far away in the firing order. If the roughness moves you have found the problem. If it doesn't and you have new plugs fitted then you need to look further.

 

How did the plugs look? This engine does appreciate fresh ones, it might just be as simple as that.

 

Look at 'ger's M5' thread post 183 on m5board where he went through how he found what appear to be equivalent cam position sensors. Was a while ago but may still be useful.

 

How many miles have you done since resetting the adaptations? If it is less than a couple of hundred they may not be fully settled yet and you are chasing a non-existent problem, with luck!

Thanks, found the thread with part numbers - a big difference in cost

 

Just wondering whether I should change all sensors while I have plenum off doing other jobs - total cost around £180 for 4 cam sensors and 2 tps's

Edited by B21playa

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Getting those fuel trims back to where they were before you reset them is key to diagnosing so much. It is difficult to rule out a simple air leak without seeing fuel trims. What are they at present?

 

Do you have any record of the MAF sensors being replaced? They are a known weak point and can cause hesitation / rough running issues.

 

If you feel you need to strip the top down then yes it is a good time to do the other sensors. At least you then have a good baseline for further diagnostics. The usual 'money no object parts cannon' m5board plan of attack on an unknown M5 is MAFs, vanos solenoid service, cam sensors, pre-cat O2 sensors, fuel filter. I have always erred towards diagnostics rather than parts cannon but that's just my preference!

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Plugs finally changed and tried vanos test again and even raising rpm it failed.

 

ive ordered new seal kit and removed bank 1 vanos solenoids. Need new dust gasket.

 

is it possible to get new o-rings for the solenoid to board? Just need to test them all following a guide I’ve seen

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When I changed my solenoid o-rings I only changed the 8 larger and 8 smaller on the solenoids themselves.  I couldn't find the parts I think you mean on the realOEM link here:

 

http://www.realoem.com/bmw/en/showparts?id=DE92-EUR-06-1999-E39-BMW-M5&diagId=11_2674

 

You need parts 3 (x8) and 4 (x8) to do both sides.  These were about 60 quid all in I think.  They're a special 'D' profile so any old standard o-ring probably wouldn't do the job.  From reading in the past, any oil leaks from solenoids come from the solenoid o rings themselves.

 

While the solenoid board is out it's well worth checking they all fire correctly with a 9v battery and some wire.  There's threads on M5board for info,  one or two may need the solder re-flowing due to heat cycled/cracked joins.  I did mine and one of my solenoids didn't fire until I repaired it.  All should click audibly especially after removing the gauze filters (if present) and blowing compressed air/carb cleaner through the holes while firing to clear them out.

20180903_144244.jpg

Edited by DatV8

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8 hours ago, DatV8 said:

When I changed my solenoid o-rings I only changed the 8 larger and 8 smaller on the solenoids themselves.  I couldn't find the parts I think you mean on the realOEM link here:

 

http://www.realoem.com/bmw/en/showparts?id=DE92-EUR-06-1999-E39-BMW-M5&diagId=11_2674

 

You need parts 3 (x8) and 4 (x8) to do both sides.  These were about 60 quid all in I think.  They're a special 'D' profile so any old standard o-ring probably wouldn't do the job.  From reading in the past, any oil leaks from solenoids come from the solenoid o rings themselves.

 

While the solenoid board is out it's well worth checking they all fire correctly with a 9v battery and some wire.  There's threads on M5board for info,  one or two may need the solder re-flowing due to heat cycled/cracked joins.  I did mine and one of my solenoids didn't fire until I repaired it.  All should click audibly especially after removing the gauze filters (if present) and blowing compressed air/carb cleaner through the holes while firing to clear them out.

20180903_144244.jpg

 

Thanks, I’ve got a set of viton o-rings for both banks, but only doing bank1 now as that’s the one failing the test.

 

Taken board and and cleaned through 2 of the solenoids so far and the click is a lot better. Do the plastic gauze rings need to go back on?

 

I’m going to clean the board up and reflow all joints to be in the safe side. Was hoping to get it back in tomorrow but the gasket for the cover is damaged so will need to order a new one

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5 hours ago, B21playa said:

 

I’ve got a set of viton o-rings 

 

Posts on M5 Board say that the Viton seals shred and you need to use the Genuine BMW “D” seals

 

5 hours ago, B21playa said:

Do the plastic gauze rings need to go back on?

 

No, leave them off.

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17 hours ago, B21playa said:

Is it possible to get new o-rings for the solenoid to board?

 

Are you talking about the grommet that holds the solenoid to the board? It is used to locate the solenoid in the board and isn’t technically necessary.

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4 hours ago, Rosie said:

 

Are you talking about the grommet that holds the solenoid to the board? It is used to locate the solenoid in the board and isn’t technically necessary.

Yes, thanks for that

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4 hours ago, Rosie said:

 

Posts on M5 Board say that the Viton seals shred and you need to use the Genuine BMW “D” seals

 

 

No, leave them off.

Oh right - not sure what to do. The existing ones actually still have there D shape

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Ended up leaving old o-ring on as they looked fine. Ran vanos test again and it failed but not getting any fault codes at all. Still doesn't feel right.

 

Had to put the car back together as need the garage to do valve cover & oil filter housing gasket on our e90 330i. Once that's done I'll get it back in the garage and remove plenum and sort out oil separator hoses

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Some good tips here, although I wouldn't discount bad coils. They go bad just like any other car and 20 year and 144k miles is more than enough for them to go squiffy. I know a few owners, including myself, who have had to change them.

 

Another vote for Ger's alternative cam sensors. I put some febi and vemo ones in, they fitted perfectly, solved my issue and have been fine for several years so far. Plus all 4 cost the same as 1 genuine sensor from the stealers!

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Thanks - I have the cam (Delphi & Febi) & throttle (delphi) sensors, just waiting for a good deal on the coils. autodoc had 22% off but missed that and now only 17% and that helps when buying 8

Edited by B21playa

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