Rattle Engine Noise under acceleration

[mejim707]

Sorry to resurrect an old thread. but it sounds like this is exactly what I'm experiencing as well, however add oil makes no difference. It old happens when under load, never while idling or revving engine while stopped. The engine power is good as well. It happens from about 1500 - 2800rpm and only when accelerating. It changes loudness / speed the harder I press the gas even though the RPMs may not be increasing that much. It seems very much so tied to the increase of fuel but I'm baffled that it only happens while driving. Never while stopped.

One note, I do have the engine light on. p0420 / p0430 codes for cat running inefficiently. Could this rattle be a bad cat? If so, would a bad cat rattle like this only under load / accelerating or shouldn't it also do that at idle.

Here is the video of the rattle. It's pretty faint and could be mistaken for wind noise but you can hear it stop when I let off the gas.

https://www.dropbox.com/s/4l2q0mg074...Video.MOV?dl=0

Thanks

[CLS70]

Hi - I listened your video and although I was able to hear the noise it was difficult to compare (maybe I will try to record mine) but I noticed yours is way more constant that the one I experience; the rattle on my engine lasts at most 1-2 secs under load and goes away - sometimes is not even there

Coincidentially, my rattle came back (and is Winter time as the last time.....maybe it has something to do with it -- --) - I removed the plastic engine cover (the vanity one) to check for loose stuff with no luck so far.....

[mejim707]

This may be one of the fastest updates ever, but, have your checked your DISA? I've been pulling parts and inspecting them all week. After making my post I was able to pull the air box, then DISA and sure enough, it's broken!! The flap moves freely and should not move at all without the computer controlling it. I'm going to the dealer tomorrow morning first thing to get the part. I'm hoping this eliminated it once an for all, but, looking at the evidence here it should.

[bmrboi2]

Its your drive belt tensioner. Same thing on my last 2 N52 engined BMWs. Always in the extreme cold winter temperatures. Replaced the tensioner and that was that.

[CLS70]

Originally Posted by mejim707

This may be one of the fastest updates ever, but, have your checked your DISA? I've been pulling parts and inspecting them all week. After making my post I was able to pull the air box, then DISA and sure enough, it's broken!! The flap moves freely and should not move at all without the computer controlling it. I'm going to the dealer tomorrow morning first thing to get the part. I'm hoping this eliminated it once an for all, but, looking at the evidence here it should.

LOL - I was online when got your message -- I will check the DISA valve this weekend...thx.

[mejim707]

Originally Posted by CLS70

LOL - I was online when got your message -- I will check the DISA valve this weekend...thx.

@CLS70, did you have a chance to check your DISA? Hoping thats the issue. My car is running perfectly, and for 182k, the engine sounds and runs like new.

[CLS70]

Originally Posted by mejim707

@CLS70, did you have a chance to check your DISA? Hoping thats the issue. My car is running perfectly, and for 182k, the engine sounds and runs like new.

Hi - not yet - I'm traveling for the next couple of weeks so X5 is parked @ home.....

[CLS70]

Originally Posted by mejim707

@CLS70, did you have a chance to check your DISA? Hoping thats the issue. My car is running perfectly, and for 182k, the engine sounds and runs like new.

Have been unable to check the DISA - no time - now is the alarm going off (different thread) - temperature is a bit warmer and the engine sound has not showed up again, although I have driven the X5 only a couple of times in the least few weeks and for a few KM only so not a lot of 'sample time' to check if the noise is present or not...as soon as I can will check the DISA