engine clatter at idle after warmup

[88535is]

My 99 540i with 166,000 miles began making a clatter sound at idle after warmup. When engine first starts cold the sound seems normal. When warm and clattering at idle, the clatter sound is not noticeable at higher rpm. The sound comes from the right front of the engine. What could be the source?

[shogun]

top or bottom of the engine, right side from driving direction there is the timing chain tensioner https://www.realoem.com/bmw/enUS/sho...diagId=11_7556
or one of the pulleys in front of the engine from the belt tensioners? https://www.realoem.com/bmw/enUS/par...BMW-540i&mg=11
get a cheap mechanics stethoscope, with that it is much easier to find the source of the noise, costs abt $10

[88535is]

top or bottom of the engine, right side from driving direction there is the timing chain tensioner https://www.realoem.com/bmw/enUS/sho...diagId=11_7556
or one of the pulleys in front of the engine from the belt tensioners? https://www.realoem.com/bmw/enUS/par...BMW-540i&mg=11
get a cheap mechanics stethoscope, with that it is much easier to find the source of the noise, costs abt $10

Hi - thanks for the reply. clatter if from the right front of the engine.. I suspected the tensioner and was going to remove it to see its condition.. but I don't see how I can get access to remove it directly, even after removing air cleaner unit. I saw a youtube video to do that but it was a 6 cylinder.. I have the V-8. What may I have to remove to get access?

[632 Regal]

Remove the fan shroud, then loosen the tensioner and remove the first belt and check for the noise. If you can't get enough access that way then remove the fan. Pretty sure you can do that without removing the fan tho. Don't run it too long cause the water pump isn't working. If the noise is still there then go to the next belt and tensioner for the AC unit. Spin the idler by hand and feel for smoothness, you got this right? If the idler feels smooth check the pulleys for alternator and water pump etc etc.

If the noise remains I would next assume your oil pump bolts are mostly in the bottom of the oil pan. Get a lower pan gasket and get to work, also tighten the chain a bit. This is in no way rocket science and can be done on ramps. Every single V8 I have checked have bolts in the pan. My current 530 only had 2 bolts in the pan but all the rest were loose. I had no noise or issues, it's just a thing I check.

Edit: you can clean and loctite the pump bolts and holes or just tighten them and hope you don't over torque them. I usually do the loctite thing.

Good luck and keep us posted.

[genphreak]

If the noise remains I would next assume your oil pump bolts are mostly in the bottom of the oil pan. Get a lower pan gasket and get to work, also tighten the chain a bit. This is in no way rocket science and can be done on ramps. Every single V8 I have checked have bolts in the pan. My current 530 only had 2 bolts in the pan but all the rest were loose. I had no noise or issues, it's just a thing I check.

Edit: you can clean and loctite the pump bolts and holes or just tighten them and hope you don't over torque them. I usually do the loctite thing.

Good luck and keep us posted.

* Adding the obligatory 2c: I'd add to clean the holes really well, blast them with compressed air, squirt alcohol in from a syringe or something, dry with compressed air... clean the bolts too, and then Loctite.

Jeff- have you found this with all your M60s? I have one that sounds very chain-like to me, so I expect the tensioners are cracked and in need of a change. New ones cost a packet, so I've been stalling. My good friend did the pump in this one a few years back and loctited it, so I've not bothered checking it. Do you think there's a good chance it might just be the pump?

Maybe I should poke closer with a stethoscope and see if I can locate the noise, I wasn't thinking the noise could be due to the oil pump bolts. Is it the pump drive chain that loosens when enough bolts come out?

[632 Regal]

Jeff- have you found this with all your M60s? I have one that sounds very chain-like to me, so I expect the tensioners are cracked and in need of a change. New ones cost a packet, so I've been stalling. My good friend did the pump in this one a few years back and loctited it, so I've not bothered checking it. Do you think there's a good chance it might just be the pump?

Maybe I should poke closer with a stethoscope and see if I can locate the noise, I wasn't thinking the noise could be due to the oil pump bolts. Is it the pump drive chain that loosens when enough bolts come out?

I think the oil pump chain loosens with wear / age. It's really a small chain so I doubt you would hear it making any noises. Every M60 I have looked at inside has loose pump bolts not just mine. I have not seen an issue with the timing chain guides, I suppose the tensioners can fail and cause noise though. We have 3, the main chain and both cam chains.

Chain related sounds can be anything that's sucking air too, steering, transmission etc. I think you need to zero in on the sound before we tear that sucker all apart.

From all I read the guide issues are the M62's with vanos due to the single chain wearing.

==========

One time when I was changing valve cover gaskets I dropped a bolt down stairs. Started it and wholey clackety clack with a misfire. I freaked and tore it back down and saw nothing. Come to be a misfiring coil causing a miss. No idea why it made such a terrible noise but it did. Have not been able to get the stomp test to work since that day but not complaining either.

[88535is]

top or bottom of the engine, right side from driving direction there is the timing chain tensioner https://www.realoem.com/bmw/enUS/sho...diagId=11_7556
or one of the pulleys in front of the engine from the belt tensioners? https://www.realoem.com/bmw/enUS/par...BMW-540i&mg=11
get a cheap mechanics stethoscope, with that it is much easier to find the source of the noise, costs abt $10

Thanks again for the info.. it was the timing chain tensioner, replaced it yesterday and clatter is gone.