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wolfman

M54 rough running

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OK my 530 touring has been messing about lately. I thought I had it sorted with a dodgy new inlet cam sensor but no. Tonight it is throwing up loads of faults mainly o2 sensors but I don't know which one's  Or  which bank or pre cat or post cat. It is missing and running rough so I did a data stream here are the pictures of the read out what do you think.

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Edited by wolfman

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Looks like it is running open loop (not using the oxygen sensors) because it can no longer adjust the mixture enough to get it things running properly, which probably also the cause of the misfires. I'd check the M54's usual suspects first and vacuum leaks in particular, dry rotted vacuum hoses are extremely common on these engines as they age. There are also some blind plugs on the back of the manifold that tend to dry rot and cause leaks.

 

Edited by Carlton

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1 minute ago, Carlton said:

Looks like it is running open loop (not using the oxygen sensors) because it can no longer adjust the mixture enough to get it things running properly, which probably also the cause of the misfires. I'd check the M54's usual suspects first and vacuum leaks in particular, dry rotted vacuum hoses are extremely common on these engines as they age. There are also some blind plugs on the back of the manifold that tend to dry rot and cause leaks.

 

 

 

^^^

 

This; also check the intake boots from MAF to throttle body; inspect carefully including the small section by the throttle body; any splits/cracks etc, replace it

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As above, i'd be looking as the rubber intake boots.

Clear the adaptations when done and it'll re-learn the fuel and air mix and sort itself out.

Also CCV issues can cause problems, been there and done all that and probably every other job on an M54 over the past ten years!

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On 16/09/2020 at 20:49, mike77 said:

As above, i'd be looking as the rubber intake boots.

Clear the adaptations when done and it'll re-learn the fuel and air mix and sort itself out.

Also CCV issues can cause problems, been there and done all that and probably every other job on an M54 over the past ten years!

Thanks for the help guys I found a couple of splits in the intake boots and a small one by the dipstick. I silicone sealed them to test it out and have done a couple of hundred miles and all seems good. I have now ordered both intake boots and a CCV kit and will get them on soon. 

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12 minutes ago, wolfman said:

Thanks for the help guys I found a couple of splits in the intake boots and a small one by the dipstick. I silicone sealed them to test it out and have done a couple of hundred miles and all seems good. I have now ordered both intake boots and a CCV kit and will get them on soon. 

 

When it comes to the CCV kit; my advice is to always get the Meyle one via C3BMW, c£80 - don't use a crappy eBay one (so hopefully you've done this or similar) and also get the intake manifold gaskets (Elring) and take the inlet mani off and do the CCV that way. It's more to take off, but it gives you a lot more room to play with and you're not having to remove/fit things 'by feel'

 

Also gives you better access to the dipstick tube, so you can give that a good cleaning and replace the O rings etc :) 

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On 23/09/2020 at 16:19, d_a_n1979 said:

 

When it comes to the CCV kit; my advice is to always get the Meyle one via C3BMW, c£80 - don't use a crappy eBay one (so hopefully you've done this or similar) and also get the intake manifold gaskets (Elring) and take the inlet mani off and do the CCV that way. It's more to take off, but it gives you a lot more room to play with and you're not having to remove/fit things 'by feel'

 

Also gives you better access to the dipstick tube, so you can give that a good cleaning and replace the O rings etc :) 

Yes I did get the bits from C3 and the old girl is done now, So I will see how it goes. Only thing I must admit is I did do it without removing the manifold and did not find it to bad.

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How long does the CCV system last on these engines? Mine had it done by a previous owner about 7 years ago but is starting to show the odd symptom that makes me think it might need doing again.

 

also does anyone have a diagram of where all the vacuum hoses are that need checking?

Edited by lufbramatt

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1 minute ago, lufbramatt said:

How long does the CCV system last on these engines? Mine had it done by a previous owner about 7 years ago but is starting to show the odd symptom that makes me think it might need doing again.

 

Depends on which CCV kit they used; some last months, others go for ages.

I think it's down to how many short runs are done in these cars etc and how well the cars looked after

 

If you need to do it; get the Meyle CCV kit from C3BMW

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