540i Timing Chain Guide Noise - Help

[imrann83]

Hi All,

New to the community! Purchased a 2001 540i a couple months back and love it. The car has 174k, but the Timing Chain Guides (including tensioners) as well as Vanos units (rebuilt) were completed at 155k (2 yrs ago by Harrison Motorsports - for those in ATL), but I seem to have a rattle/tick (all the time, not just at start up) and would like your thoughts. I took it by an indie (EuroFed) and they mentioned that the sound is not normal and seems that there may be something "slapping" and would require taking apart the motor to investigate. The sound is coming from the front driver's side of the motor, but does not occur on the passenger side.

Also, ran for codes and none came back. Other than that, it runs great.

Would like your help if to know if this is something alarming or if its the normal Vanos noise or if I have something bigger to worry about? ANY help would be much appreciated! See link to video below. Thanks in advance!

https://youtu.be/erNHDWe5BW8

[JimLev]

Sounds like the vanos of possibly a lifter.
If you increase the RPM is it still there?

[imrann83]

Yep, it is.

[JimLev]

Does it sound like it's coming from the very front of the valve cover?

[imrann83]

Yep, on the driver's side.

[geargrinder]

I hate to say it but its easy to get these timing jobs off by a little if you're not super meticulous and/or experience with them. Even great BMW Indy's dont tend to do a lot of these older V8's.

However its your lucky day because I actually watched your video (I hate watching videos)...

And I'm wondering if it might be a SAI tube leak.

Because the SAI tubes are super soft aluminum its actually possible to get the tab bolted in and have it sorta bend down into place while the actual tube itself is not sealed. The tiny exhaust leak that causes, tends to sound like a clackclackclack noise much like that. You could stick a piece of pipe down there and listen to the end (ghetto stethoscope style) right where the SAI tube goes into the head to confirm it. Normally you might also get an SAI code if the ECU doesnt see the O2 AFR respond to the pump being on, but it could be the tube is half over the hole enough to pump some air in and not throw the code... (or maybe you DO have a code..?)

Here's a shot of the SAI tube being removed... You'd want to stethoscope around where the drivers side pipe is.



Bit of a long shot but it'd be a great solution vs a stuck lifter or bad timing chain job needing a re-do...

[edjack]

GG may have a point.

[kouks]

Not a lifter, those are higher pitch.

I'd inspect the SAI pipe, a lot less work then a timing chain, and the only way it could "fail" is the retaining screw coming loose. Check the torque on that screw, and generally accessible on the driver side.

Any startup noise on that side? Could be a VANOS gear.

Timing chain noise is not as dull a sound, more like a slapping sound. Only real way to confirm timing guides is dropping the oil pan and checking for plastic parts.

Loose spark plug?

Loose coil causing a spark plug to be erratic?

Failing fuel injector?

The last three items may start to cause a light wobble in the engine and will follow rpm.

[imrann83]

Thanks for the help guys! Time for me to start digging!

[imrann83]

Hey Fellas,

Had a shop take a look and turns out its the VANOS units. Looks like it'll be costly, but from what I have read, you can run on them for a while; I have no symptoms of loss of performance, mpgs, low end torque issues, etc.

[geargrinder]

I'm skeptical.

VANOS were done 2 years ago? Have you confirmed that at Harrison with cars VIN and records etc., or was that previous owners claim? Maybe he just did the chain guides and NOT the VANOS? Really imperative to confirm this.

Possibilities:

1. VANOS were done but they did them in-house or bought them pre-done by a crappy seller, and the left one wasn't done right or pressed hard enough and something blew out / slipped
2. VANOS were not actually done 2yrs ago and then indeed one is crapping out. Except normally they age together, less likely to have one be a total fail like that noise would suggest.
3. It isn't actually VANOS.

What shop says its the VANOS? I want a 2nd opinion and I want that to be from somebody who knows M62TU's really well.
Someone with the right gear should be able to drive the car and log cam movement and see if the VANOS on each bank is working.
Typically if the VANOS is that dead you should get a code for it but even if not you should be able to log one side moving and the other not moving.

And if it is truly ONLY VANOS, and ONLY the one on that side (aka Scenario 1 above) the job isn't too terribly bad. You'd only have to take the one lower-timing cover off, then lock up the cams, pull the VANOS hub etc. etc. Far short of a full timing chain job.

If its Scenario 2 - VANOS weren't really done w/ the guides - (which I think is a solid possibility until proven otherwise), then you really have to do both sides at the same time or you're wasting a ton of money because the other side is going to go sooner than later also. Even in that case the job again isn't too terribly bad. Probably just less than a full day for a pro who knows the motor.

If its Scenario 3... then obviously you don't want to waste time and money on ​any VANOS screwing around...

[imrann83]

Hey GG,

Confirmed with Harrison that the VANOS units were done, but were rebuilt units. Yes, definitely getting the sound on the driver's side valve cover. Markert Motorworks was the one who took a look at it as I wanted a 2nd opinion before taking to Harrison (he has a decent backlog at the moment and couldn't fit me in right away). Markert from what I hear is a very reputable shop as is Harrison.

[geargrinder]

Yes virtually everybody puts in a rebuilt unit (or does it themselves), the BMW parts are crazy cost prohibitive, and, there's some argument the rebuild might be better anyway. Have to say don't often hear of the process going wrong but knowing how its done for sure the new seal could get put in twisted or pinched and then blow out later if the guy doing it isn't careful. Did Harrison re-build them themselves or did they buy them from some immmerewbz source?

Like I said, if you could log the cam movement to confirm while you're waiting for your backlog spot to come up that'd be a really good idea... For sure there are forum dudes in the ATL with cables that could help with that, if you're lucky you can find somebody to do it for beers and a burger or something.