M62tu 'diesel knock'

[Themoog2]

Talking of subframe bushes... I’ve had a slight harsh/ vibration feeling going on gentle throttle at about 2000rpm for ages. It was a lot worse a while ago until I found that one of the rear muffler hangers under the rear bumper was loose and when I tightened that up the harshness reduced. Other people have driven it and don’t feel it but I do.
Now, this harshness is not always there. Sometimes it’s ok and this got me thinking. As the other exhaust hanger is bolted to the subframe bush housing- could that be the source of the vibration? Especially as the bushes are shot? Could it be that the movement in the subframe bush is affecting the exhaust resonance that can be felt in the car? interesting. Please put your thoughts across.
I’m going to replace the bushes so we will see.
There is a NVH app for Android that can narrow down vibration in a vehicle. It’s a bit pricey at £90 but I may download it to see if it’s any good. My aim (if I don’t change) is to make the X5 more ‘luxurious’ if you catch my drift.
Like I said earlier, the E53 is getting a rarer sight on the roads and I actually like the car. Plus it’s a bit of a hobby messing about with it.

[henrym3]

That’s an expensive app. Would/could be wasting money as you are going to change the subframe bushes anyway. If it’s still there after changing the bushes then perhaps/maybe worth considering. As parts of the suspension including the ARB are attached to the subframe if the bushes are knackered then it has to have consequences elsewhere. If any of the prop shaft joints are worn that will cause vibration, at 20yo probably worth doing front and centre.

[Themoog2]

Going back on track about the vanos I’ve been thinking...
Obviously I want the noise to go away at minimal expense so I’m going to remove the vanos solenoids to give them a really good clean out followed by changing the oil and filter to see if it makes a difference. The thinking behind cleaning the solenoids is that maybe they are a bit gummed up and not allowing full oil pressure? Just throwing it out there as you never know.
As for the oil - I’m sure the engine wasn’t as loud before I changed the oil last year. It had shell helix in it. I may try a liquimoly flush too.
Thoughts..

[henrym3]

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41EC476B-70B1-4B23-9633-B81581FE9394.jpeg (120.42 KiB) Viewed 1357 times

You never know what you will find when you start fiddling. This was BMWs solution to stop the solenoids leaking out of the covers. It didn’t stop the "o" rings from busting and causing the cam timing to be wonky

[Themoog2]

What on earth is that mess..