I have an 04 R53 JCW. I have a rattle that sounds like it is coming from the passenger side of the car from the bottom side of the engine or under carriage. It does not change no matter what I do, accelerate, decelerate, clutch in or out, change gears, brake, rev the engine, etc.... It does not get worse, louder, quieter, basically no change in sound no matter what. There is no rhyme or reason as to when it happens and by the time I get out of the car to see if I can locate it, it stops. I have tried to record it but have not had any luck. I can't find anything that is loose. The car runs the same when it does occur. The car is running great. It will last anywhere from a few seconds up to almost a minute. Anybody have any ideas?

 

What kind of rattle & on what conditions does it happen?

 

Well passenger side is the belt area so could start there.

 

If it's rotational at right bottom side (aka: Front of Engine ) while engine running/parked, could be a few different things....

The Hydraulic Belt Tensioner. 1st make sure the belt isn't just worn out. Slack in the belt will make the metals of the assembly rattle some creating somewhat of you describe. Should be at least 3/4 of the top hole showing in the metal strip running through the top of the spring.

If belt is good, could be one of the bushings at either end of the hydraulic tensioner has worn out. THAT will rattle for sure. If so, only comes as complete assembly.

http://www.ecstuning.com/Mini-2004-C...eys/ES2684956/







I have also seen instances where it was either the idler pulley...

http://www.ecstuning.com/Mini-2004-C...lleys/ES21587/








and even the Crank Pulley aka: Crank Damper Pulley can make some noise when worn and in worse cases can cause a CEL to come up.

http://www.ecstuning.com/Mini-2004-C...lleys/ES20548/

When this one is toast, check the crank seal too for leaks


http://www.ecstuning.com/Mini-2004-C...Seals/ES17600/





Best to do at same time when going thru all that trouble. The bolt used for this pulley should not be reused, but has seen some use blue loc-tite during re-installation.

 

It is what I would call a medium, metal to metal rattle that does not change in speed or sound no matter what you do. It starts at random times under any condition, 75 MPH, idle, in neutral, under acceleration, coasting, and I even think it started one time when I turned the key on before I started cranking the engine over. It stopped after approximately 1-2 seconds so I was not sure.

Belt was just replaced approximately 5k ago and still looks good.

gRay rAvEn, I will check those. I would have hoped the mechanic would have when replacing the belt but he may not have. I can't remember if it was doing it before the belt was replaced now that I think about it. More pressure on those parts could have caused them to start failing.

Thank you all for your help. I'll keep you informed.

 

I said belt area, not limited to the belt. My guess is your tensioner, likes to make a metallic ringing sound.

 

I just got this same problem except mine sounds like a diesel. I think its the chain tensioner. the sound goes away only after 2500 rpm. what do i do. buy just the tensioner or the whole chain kit including the sliders.

 

Mine is still staying constant no matter what RPM and then it just goes away for no reason. It does kind of sound like a Diesel engine but it does not speed up or slow down no matter what you do.

 

I figured it all out. The problem is the tensioner is getting stuck. I just pulled my out chain tensioner and it was completly pressed in like it was brand new from the box. Not good is suppose to be out and easy moving. I tried to free it up but it was just to choppy. Take a look at my video you can see my hand being choppy while i use the same force throughout to force it down. The reason why sometimes yours goes away is because it gets freed and then it works good until it gets stuck again. Im gonna buy a new one tomorrow hopefully i didn't do much damage to my rails. I only drove for a minute before i shut it off. And yes the noise would go away after 2500 rpm. The chain sounds horrible before that. Like a diesel exactly like a diesel.

 

Does the crank have to be rotated the change the tensioner? I'd like to change mine soon.

 

no. just take the right front wheel off and jack the car up. nothing needs to be even taken apart. but there is a problem lol. since im not gonna open the timing cover. (everything has to come off crank pulley, belts) i need to insert the new tensioner in the open position. so i need pressure to push and turn the screw to get it in. gonna suck but im gonna do it. taking the whole timing cover will be a few hours job. And if im doing that then i rather replace the sliders and chain if i see damage. But not gonna happen hopefully their is no damage.

just unscrew the tensioner bolt and the tensioner will pop out with it. little oil too but nothing crazy. since mine was stuck closed. i unscrewed it with my hand and the tensioner slide right out easy.

Im assuming you know where the bolt is located if not here it is. 19mm you need a shallow socket an extension and a swivel. but i managed to get it out without a swivel and the extension not fully in the socket. got lucky.
http://www.google.com/imgres?imgurl=...tart=0&ndsp=20

 

Well today I went to the dealer and bought the tensioner and opened it right there. My Blood instantly started to boil when i tried to compress and retract it. It felt like the same thing, very choppy at certain point. (Just like the original one) But that didn't matter i still got home and tried to put it in.
To make the story short the new tensioner fixed the problem. Here is how i got it on.

1. Unlock the tensioner by pressing it fully in till it opens all the way out. (New one will be compressed in)
2. Two people will be needed but i got it on by myself because i took my valve cover off. (valve cover doesnt need to be removed)
3.One person will be controlling the crank pulley. Turning it clockwise very slowly.
the second person will try to insert the tensioner until you will be able to put the bolt onto its threads.
4. You will have to put some pressure pushing the tensioner in while the other person tries to to rotate the crank clockwise very slowly.
5. As soon as the threads catch use your socket and ratchet to tighten it all up. Then your done. You can put the wheel back on and start the car.

 

I can't believe you did not hold a video camera in one hand so we could see how you did it! Jeez

 

haha thanks.the point is to have slack on the chain so the tensioner bolt can start the threads.