Odd sound from M54 3.0 engine 2003

Hey folks, any help would be appreciated. I've talked to several mechanics and no one has firm ID on what the problem is.

The M54 3.0 engine on my 2003 Z4 is making an odd sound when its hot. It does not make the sound when the engine is cold, and takes about 15-20min to get warm enough for the sound to start up. My car has 101k miles. I've found a Youtube video from someone else with the same problem.



It can best be heard in the video between 0:40 - 0:50. It's not the CCV, just replaced it. One theory is that its the oil pump.

Thanks in advance!

From what I know can be VANOS rattle, chain tensioner inside engine, or AC compressor belt tensioner pulley or/and tensioner (easiest to fix).
Not sure about AC clutch. Try to on /off AC an listen if it changes. USE different oil may calm down a bit VANOS rattle if it the case. Chain tensioner may diagnose very good mechanic I guess.

Its not coming from the VANOS or any of the tensioners on the belt system. It makes the sounds independent of the A/C. It could be the chain tensioner. If it's that or the oil pump, huge dollars to drop the oil pan I've been thinking about putting thicker oil in to see if it helps.

I have the same rattle after start up. It is a growl of sorts. It is not coming from any tensioner or the Vanos. I am curious what it ends up being. Keep us posted. I took off the DISA valve, but is appeared to be in one piece and tight. I am at a loss on what to do except listen to it or turn up the radio.

Originally Posted by RoyFokker

Its not coming from the VANOS or any of the tensioners on the belt system. It makes the sounds independent of the A/C. It could be the chain tensioner. If it's that or the oil pump, huge dollars to drop the oil pan I've been thinking about putting thicker oil in to see if it helps.

Hard to say what it is from that video. Phone camera's don't pick up sound well. Personally, I think it sounds like valve train noise, and maybe normal. Chain tensioner's and oil pumps are unlikely failure points. Is your car full of the proper weight oil? How often do you change it and when was the last change?

It's been making the sound for the last 10000 miles or so. It's gotten maybe a tiny bit worse since then. I'm running the standard BMW 5W-30 synthetic. It's not the DISA, just replaced that about 20k miles ago.

I just replaced timing system. Chain, tensioner, cam chains, and gears. Yes its a big job. Must pull the head because the gasket covers the area between the head and the timing cover. The easiest way was to remove the entire front of the auto. Only the frame and block and front tires were left infront of the firewall. Three K for the job but after 230000miles parts wear out.

Did you ever figure out what this noise was? Mine has started making the same noise, or at least sounds very very very similar.

It's not the belts / pulleys / water pump. It seemed to start after a belt / pulley refresh, but we took the belts off and the noise was still there.

It seemed like maybe it was coming from the crank damper pulley, and placing a screwdriver just below this I could hear the noise very very faintly. I think the oil pump is around this area, but it really was faint, so I'm not sure....

It only seems to happen on warm idle. If the car's cold it sounds fine.

Oil was changed only about 2k miles a go, shortly after I got the car. Mobil1 0w40 New Life.

I never was able to figure out what was causing the sound. I changed the oil with Mobil 1 0W-40 and the sound pretty much went away. After about 4000 miles the sound has come back. I had an oil analysis done by Blackstone and it showed some bearing wear. Regardless, it's either the oil pump or something being lubricated by the oil. Overall my car has been making this sound off and on for more than 20000 miles so I'm not sure what to make of it.

I'm probably going to change the oil again soon and see if it makes the sound go away again (and run another oil analysis).

Originally Posted by RoyFokker

I never was able to figure out what was causing the sound. I changed the oil with Mobil 1 0W-40 and the sound pretty much went away. After about 4000 miles the sound has come back. I had an oil analysis done by Blackstone and it showed some bearing wear. Regardless, it's either the oil pump or something being lubricated by the oil. Overall my car has been making this sound off and on for more than 20000 miles so I'm not sure what to make of it.

I'm probably going to change the oil again soon and see if it makes the sound go away again (and run another oil analysis).

That's quite interesting.

Have you always used Mobil1 ? I've come across a couple of posts claiming it caused people to have a 'noisy engine'. Seemed mad to me at the time , but i wonder if that is all it is ? One video of the same sound on YouTube (took me ages to find !) Claims they changed with standard BMW oil and it has not come back.

Do you do a lot of short journeys ? I do , unfortunately, So i guess maybe this has accelerated the issue for me... as mentioned previously my oil is only 2k old , but i have started to get a bit of mayo from condensation (not loosing coolant as far as i can tell)

I might change the oil and see if it goes away. I'm just not sure what to change it with.... Mobil1 again... bmw stuff.... i hear German Castrol is great.

Ill let you know what happens my end anyways :-)

Sounds fairly typical for a BMW I6....they ARE machines, after all....

It started making the noise while I was using the BMW 5W-30 oil. When I changed the oil to Mobil 1 the noise went away for about 3000 miles then came back. I'm thinking of changing the oil again soon to the new Amsoil 5W-40 European formula (code EFMQT-EA) that meets the BMW LL-01 specification (it just came out in Oct).

I've been using Amsoil for years in other cars and it works well.

I do mostly highway driving with mine. I'm starting to think that it's fresh oil that helps, not necessarily the type. After the oil starts breaking down it's not quite lubricating as well, and the noise creeps up. Hopefully it's a problem that won't manifest itself for a long while!

Originally Posted by RoyFokker

It started making the noise while I was using the BMW 5W-30 oil. When I changed the oil to Mobil 1 the noise went away for about 3000 miles then came back. I'm thinking of changing the oil again soon to the new Amsoil 5W-40 European formula (code EFMQT-EA) that meets the BMW LL-01 specification (it just came out in Oct).

I've been using Amsoil for years in other cars and it works well.

I do mostly highway driving with mine. I'm starting to think that it's fresh oil that helps, not necessarily the type. After the oil starts breaking down it's not quite lubricating as well, and the noise creeps up. Hopefully it's a problem that won't manifest itself for a long while!

The other possibility is that you`re looking to make a Federal case out of nothing....

I hope that's the case!

I hope so too. Such a strange noise though.... and just appeared all of a sudden. Weird.