After taking my Mini out for a 300 mi round-trip comfort cruise (along with some intense spiriteddriving),yesterday, I woke up this morning, started the Mini, only to be startled half to death by the sound of the most obstreperous clunking and ratteling noise I've ever heard.
I'd almost thought without a doubt it sounded like a rod about to let go. Or the once mentioned timing chain death rattle since the noise resonated upon acceleration and deceleration.
Upon further investigation with a stethoscope - Thank heavens it turns out to be the exhaust hangers are shot and not something internally wrong with the engine.
However lucky as it may seem to me - I've always dreaded the idea of having to drop the exhaust.
I haven't consulted the Bentley yet as to what's involved but I'm hoping it won't be as bad of a repair as I've imagined.
On a good note, though - As luck would have it; neither the flex pipe nor cat have been compromised.
Wish me luck or any advice would also be welcomed.

 

Best of luck...

Motor On!

 

Your header brought this old 'zipper club' member to a screeching halt only to find out you're OK but your li'l buddy is hurtin'. Lots of advice for the former but I ain't a wrencher so good luck with your fix!

 

If it's only a hanger why do you need to drop the exhaust?

 

The hangers are inaccessible with the exhaust in place, IIRC.

Dropping the one on the R50 wasn’t too terrible. I did mine solo, but I did have something on hand to prop one end on. I expect the R53 one is slightly more awkward since it has a second muffler.

 

I only had a moment to jack up one side of the car to crawl underneath before heading to work. I pounded my fist against the length of the pipe and could hear the noise and see the slight movement within the hangers.
However, what further conscerns me is what seems to sound like something loose rattling inside the catalytic converter. I know nothing about catalytic converters. Is it possible for these things to have internals that could degrade and break loose inside? I can hear something rattling during acceleration and deceleration but I can't tell for sure it's the cat.
Damn these drive by wire cars. There is only me and only one of me. Hard to be in both places at the same time!

 

The rear you can do - if not rusty broken. Use a block of wood or small scissors jack to support it. I did rears without taking it all out. Center too - that is a bit more tricky.

 

Nevermind - I just found a brick!
I'll try again tomorrow morning.

 

There is a substrate inside the converter that can come loose/break.

 

The cats have been known to come apart at a welded seam. The good news is that people have reported being able to get them welded back together.

 

Rule #1 for any work underneath the vehicle: Properly support on four high quality jack stands. #2 Wear eye protection. #3 wear gloves. As for noise inside the cat, yes. If the substrate breaks loose, it can clog the cat sufficiently to shut down the engine. (An ICE is an air pump and, if the air cannot escape, it will shut down). Keep in mind that the resonator can also have internal parts that can rattle.

 

Thanks for the responses.
Ok - So, I made the opportunity to jack up and get underneath the car to get a better hands-on overview of what the heck is going on with this thing.
I spent a fair amount of time = 2hrs or so, and far I can determine :
1_No split or separation from the flex pipe
2_No cracks or separation at the CAT
3_Can now confirm - No internal damage/debris to the CAT (no codes either)
My Mini has been a SouthEast climate car for all of its 21 years = virtually no rust.
Despite the obnoxious deep rattle/vibration@ 1- 1,500 rpm (at idle or deceleration) and feeling/seeing a slight bit of movement hitting the exhaust pipe with the palm of my hand all the way down its entire length; I still had a hard time trying to pinpoint where the noise was coming from. No part of the exhaust or mufflers are in contact with the body or heatsheilds.
The rubber hangers showed no physical evidence of wear or damage; However, I am left to believe these original 21 y/o hangers have to be the culprit.

I've just placed an order for a complete set of rubber hangers from Way this afternoon.

EDIT: BTW - I will be replacing all of the rubber hangers; from mid pipe to mufflers. This car is a pre-facelift '04 R53. Regardless - From your experience, would it be best to start replacements from the rear (mufflers) or replacing hangers at the mid pipe first?
Thanks!

 

I don't think it's going to matter much which direction. I've replaced all hangers on my 06, but I don't remember it being much of a challenge at all.

 

Do the center first. I have done almost all the work on mine. Drop the rear hangers. The center plate has 4 bolts, and that is how the center hangers attach. You need to drop the back to allow access to the posts on the pipe - no clearance, no access. Once you look at it, you will see. Also. Check motor mounts - weak mounts allow the engine to shift, stressing the exhaust.

 

Good that you don’t see any splits/cracks/separation. How did you determine there is “no internal damage/debris to the CAT”?

My exhaust is rattling at the moment, though I replaced the whole rear exhaust system something like 18 months ago, from the flange back including hangers and brackets . When I strike the pipe with my fist, it sounds like my noise is coming from the cat area. As you say, it is hard to pinpoint exactly, but my ears triangulate it farther forward. Do your ears triangulate your noise to a hanger area?

I replaced a rear hanger and bracket a dozen years ago when the bracket rusted out (I’m in New England). Did it in my driveway when I knew even less about wrenching on cars. Got it done but it was difficult to access. At the time I was unaware of exhaust hanger removal pliers. Get a pair. It will make the job much, much easier.

I am hopeful that your hanger theory proves on target, though I would not be surprised if the noise source were something else entirely.

 

As an aside. I had my cat welded. In the research of doing this, I read that one symptom of a cat that needs to be welded is a misfire P030* code. I had that, made me nuts - it went away.

 

To eliminate the possibility of internal damage/broken substrate in the CAT; I used a brick and my floor jack handle to prop the gas pedal at the rpms while the noise was present and tapped the bottom of the CAT with a block of wood. I did this quite often while the car was running and turned off. I heard no noise or debris rattling inside the CAT. It did seem quite distinct to my senses that a majority of the clunk & rattle seem to be more pronounced from mid pipe brackets downward to the mufflers.


Yeah, I agree. It would be just my luck to discover the issue is entirely something else. I will absolutely confirm my assumption if I find that I will have to disconnect/unbolt the CAT from the mid pipe in order to replace the rubber hanger(s).

Thanks for your point of attack. I was hoping to approach the repair with the least amount of stress. I agree - Although I had replaced all the engine mounts less than 8k miles ago, The upper is solid (good) but I suspect (even though new w/powerflex) the lower dog bone large end (no powerflex insert) may have degraded do to an oil leak (possibly PS fluid). I have a new replacement in my back-up parts box.

 

Ok. Your ears are good detectors. When I tapped on my exhaust pipe with my fist, with the car on a lift, it was clear that my noise was coming from somewhere in the area of the cat. Bad hanger is a fine problem to have.

When I replaced my exhaust, I ripped the whole thing out, replaced the brackets and hangers, and then fit the new to me exhaust in. If you’re leaving the exhaust and working around it, center seems like a good place to start, as mentioned.

 

check your heat shields.

i had a clanking noise some years ago. the shield had come loose and was clapping up against the exhaust

 

After getting under the car on a few occasions; I was hoping it was just a heat sheild that had come loose. "Sadly" that isn't the case. All the heat shields are snug and in place = no rubbing against the exhaust.

'been limiting driving the car only when necessary in hopes to avoid any cracking or separation of the flex & CAT.
The vibration noise definitely sounds like the exhaust pipe or a muffler is loose. Strangely enough the pipe and mufflers are tight and feel absolutely solid when I push or pull on them to see/feel any wiggle or play. However as weird as it seems (especially to me), I can replicate the same noise if I hit my palm against the exhaust pipe.
I'll triple check the heat shields again when I finally have full access when I replace the hangers.

New rubber hangers from WMW should arrive this afternoon.

 

I'd received the new and replaced the old rubber exhaust hangers yesterday; with little resolve. Although less pronounced than before, the rattling noise still exists.
I'd spent a fair amount of time under the car during the removal and installation to confirm all the heat shields are intact with no contact with the exhaust pipe or mufflers.
The pipe and mufflers feel super solid. I still can't help but think that there maybe some sort of debris that may have dislodged as I think I may hear the rattling coming from inside the passenger side muffler.
The rattling sound is predominantly heard at idle and between 1,100 Rpm or upon acceleration and deceleration. While running, the exhaust still has that mellow soft factory tone with no backfiring. The car sounds absolutely normal at driving speed. This leads me to believe that there is no breach or leak in the exhaust system.
My next point of approach is to replace the lower engine mount in hopes to curtail any further vibration.

 

Too bad the hangers weren’t the culprit.

How does the rubber in the lower engine mount look?

 

Look at the center mount. I had banging noises traced to the pipe not centered - one side hit the tunnel.

 

Still waiting on a new lower mount + powerflex insert for the large end. I was sent the wrong item a couple of days ago.
Strange; as the motor exhibits very little vibration to seemingly be the cause for the rattle. The center exhaust mount appears to be centered and true/no contact on the tunnel.
I'll know more when I get under there to replace the lower mount.
Hoping that the powerflex doesn't add to any noise vibration.

 

Power flex in lower dogbone is good. I found that they also make for the later hydraulic mount - it fits on the rectangle. You need two people to figure this out. One to drive, the other to listen