Hello everyone,

I have a R56 S with a manual transmission and factory LSD with about 66K miles. Lately, I get a loud 'clank clank clank' when I accelerate briskly from a stand still while the RPM hangs around 1,500 until the clutch is fully engaged. The repetition of the sound is high and goes away once the car has gained momentum. When I'm already moving with the clutch engaged and I dip into the throttle even deeper, the noise comes back with the same repetition but it isn't as loud. The noise doesn't occur when I drive very conservatively and almost always sounds like it's coming from the front but rarely like it's coming out of the back. Also, the car has never been in an accident.

The noise doesn't occur when I have the parking break engaged and start to engage the clutch while pressing the gas almost to the point that the engine stalls. Also, the noise occurs when the steering wheel is straight or turned.

I'll put the car up on my ramps tomorrow but I wanted to ask everyone where they think I should look first. My suspicion is an axle or suspension arm issue.

Cheers,
Craig

 

Definitely sounds like a CV joint going south, although at only 66k it should be fine unless one has a torn boot.

 

Thanks for the reply, K20K1LLA. Yeah, I agree, I must have torn a boot if the CV joint failed this soon.

 

Any feedback through the steering wheel when this happens? (Hmm, not sure if our electrically-boosted steering will transmit much feedback like that, but gotta ask!) Could be something in the suspension loading and unloading; possibly something like a failed bushing or a bad ball joint or tie rod?

Oh, another question--does the clanking stay in time with the road speed, or the engine RPM? Take note of both and the period of the clank when you're slipping the clutch, and possibly see if you can hear the noise in other gears. If it goes with road speed, it's something on or "downstream" of the transmission output shaft. If it goes with engine RPM, it's on or "upstream" of the transmission input shaft.

Good luck!

 

Slave to Felines,

Good questions. No, there's no feedback coming through the steering wheel. Also, the pattern of the noise seems consistent every time it happens no matter the RPM or road speed but I'll listen for that specifically this evening during my drive home.

Thanks for the reply.

 

Maybe the clutch is slipping...

 

Nahh, can't be a clutch...

My vote is an inner CV joint... the grease dries out... they get cooked by the downpipe after a while.

I've seen some cars (other brands) where they go as far as to install a protective shield over the joint to deflect heat. (I have yet to crawl under my Mini...).

But that's what it sounds like to me.

 

Maybe your hamster is hungry? Mine gets pretty peeved on hot days.

 

Everyone who suggested a torn CV boot,

I just looked under the car and the CV boots look fine. No grease residue and I didn't see or feel any tears. I tried to rotate both drive shafts with my hand and they both had the same amount of play (which was very little). Also, all of the bushings that I could see looked fine, too.

If I ran out of grease in the boot, wouldn't there be residue on the boot and/or in the area around the boot?


Slave to Felines,

The noise didn't happen when I was driving this evening. I'll listen for it tomorrow.


Velocityvic,

The noise doesn't occur when I pull the ebreak, start stepping on the gas and ease off the clutch. Also, the noise sometimes happens when the clutch is engaged and am accelerating heavily. If it was the clutch, do you think the noise would happen then?


RodSpindler,

I didn't get the hamster option when I spec'd my MINI out. I didn't want to install a super sized hamster water bottle in my garage.

 

Bonus Points for having a positive attitude and a sense of humor.

 

Nope, when they "cook" the grease "dries out". Squeeze the boots. They should not feel like they are filled with air. They should feel like they are full of grease. If air seeps out chances are they cooked.

Do you drive in deep water ever? (Or have you?).

I'll go as far as to pull clamps back for an inspection.

 

Ok, I'll check them tonight.

 

.

 

sorry I can't help with your mechanical issue, but curious about the screen name.
My wife swears that this car is only for women and men who prefer men. She just doesn't get the retro car look...

 

Tell her that it's also for anyone who is secure enough in themselves to drive a car that some people think looks "cute". Or for people who appreciate responsive great-handling cars that are also reasonably practical.

Or for anyone who wants to drive one.

 

I only had a few minutes to work on this so I didn't slide any of the boots back. I squeezed each of them and none of the four boots felt any different than the others so I don't think any of them are dry.

 

Also, I haven't driven in deep water that submerged the half shafts.

 

.

 

The repetition of the noise is independent of engine and vehicle speed. It seems like the noise occurs when the turbo kicks in and, albeit not as loud, when I take my foot off the gas. Anyone think my wastegate is the culprit?

 

I don't know what else rotates apart from the engine parts and the transmission/driveshafts/wheels. At least you have a pretty strong indication that it isn't anything inside the engine, or anything to do with the transmission or wheels/brakes/etc.

No clue about the wastegate, sorry.

 

I brought my car into the shop last night. My timing chain was elongated and has to be replaced. Thankfully no valve or piston damage.

R56 with 60,000 miles. Never autocrossed and maturely driven. I know BMW, as well as any other major engine producer, can design an engine more reliable than this. I guess the requirement for the income earned from replacement parts outweighed the customer's requirement for reliability. Nice business plan, BMW.

 

I found out that the timing chain was worse than I was initially told. Instead of it being elongated, it was actually broken. Timing chain was replaced for free by MINI.