I have developed an exhaust rattle on my 02 MCS. I have a Milltek Cat back on the car. Let me describe the rattle. It is a very tinny rattle. The rattle seems most noticable from about the middle of the car. It becomes most apparent upon decelleration. It also seems to dissappear after the exhaust has become good and hot.

Mini Center said it was the metal gasket between where the stock header and my Milltek mate. They said there is a crack in it and that the would happily replace the part for $165. I purchased the $12 dollar part so I could replaced myself. I installed the Milltek so this will not be difficult. However, I have not jacked up the car to look for myself yet (procrastinator).

Before I tackle this issue I thought you all could offer some insight.


Sean

 

If indeed it's a leaky gasket, the repair is simple. Two bolts/nuts hold the flanges together. No special tools other than a couple of metric wrenches are needed. When you separate the two flanges to replace the gasket, make sure both surfaces are clean (scrape off any remaining gasket residue or rust chunks). After replacing the gasket and tightening everything up (the bolts need to be torqued rather tightly, I am not around any specs at the moment) check the front exhaust hangers (above the plate) to make sure these are not broken or loose. Double-check the slip joint clamp and rear flange gasket for leaks and the rear hangers to make sure all is well. You are then done.

 

check to make sure the two pins on the exhaust pipe in the middle of the car whare the square plate is that the pins are are not hitting the cars under body. I had this problem with my borla exhaust.

 

Jet Black,

I have suspecteded the front hangers perhaps touching the heat shielding, is that what you are talking about?

 

Well I have played with it some and the rattle is still there. It is driving me effing insane.

I have replace the gasket where the header and the system mate. I saw spot in the heat shielding where it looked like an edge on the resonater had been rubbing. I bent it some but it actually seems worse.

While under the car I notice that the exhaust system doesn't seem to be perfectly centered in the exhaust tunel. There doesn't seem to be any way to get it to stay centered. Come to think of it I am certain that this is part of the problem because the rattle was gone for about a day, but after a day of driving and going around corners it resurfaced.

Does anyone know how I could space the system down away from the belly of the car. I think the problem is the size of the resonator...it barely fits in the tunel.

Another thought...would it be a bad idea to remove the heat shield altogether?

 

I'd keep the heat shield and try to get a smaller resonator.

 

Miltek's fit in the mini well- don't think resonator fit is the issue. I've had to replace 2 miltek resonators because they rattled inside- below 2000 rpm. purchased these at Stratmosphere and they were absolutely super to deal with as was Miltek .

 

Has to be the resonator. I had the same symptoms (rattle when cold, goes away once it is hot) and replacing the resonator fixed it. One way to check it is to put the car up with the exhaust cold and just bang on the resonator with your fist. You should hear it rattle inside.

 

bgrpph is dead on here......I had the same problem and this was the solution-Stratmoshpere is excellent with their customer service and knows of the problem.....

 

I bought the system from WMS should I go through them or should I go through Stratmosphere.

 

Call Stratmosphere

 

Thanks for the replys.

I have emailed Stratmosphere. I will let you know what I find out.

I didn't realize that resonators could go bad...is this just a issue with poor quality control?

Also does anyone remember the size of the exhaust pipe where the resonator piece connects with the rear portion of the system. I think I need to pick up a U-clamp to make the connection tighter. I hear an air leak coming from that spot.

 

I have a couple of spare Miltek clamps and you can have one, but in reality leaking is a “characteristic” of slip joint fittings in general and this Miltek product specifically. I have the joint welded but the thin wall tubing won’t hold up over time. Before you take long distance diagnostics as the answer, let’s have a look at it instead of engaging in speculation.

Here’s another thread where lots of opinions are given https://www.northamericanmotoring.co...ad.php?t=58761 . Your exhaust maybe too new to have the obvious damage seen in my pictures but it won’t be hard to determine if yours is bad or if it’s something else.

 

I just tried to call you. Is your phone off the hook? Busy signal.

 

Well I called Stratmosphere and spoke to Greg. He was very helpful and my new resonator is on the way.

Milltek has apparently redesigned the front resonator to include higher temperature packing around the perforated tube inside the resonator. According to Greg, there is an area inside the original resonator that was packed with fiberglass. The resonators were getting so hot that the fiberglass was melting into glass beeds...hence the rattle.

I look forward to getting my part and enjoying the sound of my Milltek once again.

Thanks everyone for your help. Keith, thanks for offering up your car port/tools. I'll let you know if I need help swaping out the resonator.

Sean

 

If the problem is glass beads rattling around I don't see why that would stop once the pipes were hot.
I had a bad rattle also (not Milltek) that stopped once warmed up and finally traced the problem down to a clamp not being tight enough. Check all your clamps if you have any and tighten them while the pipes are cold.

 

I had a resonator go bad as well with miltec. they were nice to replace the item but i decided to sell it anyway to prevent going thru the same thing again in 6 months.

 

I can now say my rattle is fixed thanks to Stratmosphere and the guys at 210 Performance. My rattles were two-fold.

1. I had a very tinny rattle caused by a bad front resonator pipe. This was fixed under warranty replacement by Stratmosphere.

2. After the tinny rattle was eliminated with the front resonator replacement, it revealed there was another intermittent rattle that was caused by the driver's side hanger on the resonator pipe making contact with the heat shield. While I was at 210 Performance my car was up on a lift so I had great ability to see all components of the system. It was quite obvious because the end of the hanger made a nice little circular indentation in the heat shield. Anyway, for whatever reason, my system naturally wants to gravitate toward the driver's side of the car. There is no apparent adjustment for this with the hangers on the Milltek system as they are just straight steel rods. The hangers on the factor system have lips on both sides to keep lateral movement to a minimum. So what was my solution...a very small hose clamp on the hanger butted up against the inside of the rubber hanger. I only put the clamp on the one side because there was no evidence of the system ever gravitating toward the passenger side of the car.

I hope this helps.

Sean

PS

Thanks to all for your advice and offers to help. I love the MINI community!

 

watch that the clamp doesn't destroy the rubber resonator hangers. I've not had side movement with resonator but have gone thru 3 sets of resonator hangers after lots of track time. They just rip allowing resonator to drop 1/4 to 1/2" & then pipe makes contact with metal plate. Going to try to get new hangers designed as i'm tired of replacing these to have them rip in a few track days.

 

Different problem, similar symtpoms.
... I had the same rattle symptoms, but after a while it showed up that the flex-pipe from the header was broken and small parts moved "rattle'ing" through the cat and silencers before the car got very loud with a totally broken flex-pipe.

 

My Milltek (cat-back only) had a rattle for a little while which was fixed by replacing the two rubber mounts near the centre resonator. You can see the damaged mounts below. The Bentley manual recommends changing these whenever changing the exhaust anyway. Since they were replaced, about 8-9 months ago everything has been just right.

 

Milltek: When starting from a dead stop my system rattles in first gear until I shift. It sounds like it is coming from right underneath the shifter?? I do have an Alta short shifter I"ll be taking it back to WMS to let them have a look see. Any ideas what it could be?

 

Hello all! Thought I'd revive this thread to get some opinions.

I just purchased a used Milltek catback and was checking everything is in order before I do the install (my first catback install, btw). Anyhow, since I had read this thread before I was particular in checking the resonator for rattles. When I move the resonator side to side I can just barely listen to what sounds like sand slightly moving around. My guess is that it is fiberglass particles rolling around in there. it doesn't sound like its all that bad, but I really don't have the experience to tell if this is a problem.

Can anyone tell me if this is normal, or are these the first signs of the before mentioned resonator failures? I know as a fact that the previous owner tracked his car, which had +- 16k miles on it so it has been exposed to substantial heat.

Thanks in advance

 

Sounds like the fiberglass is degrading. I just so happen to have a brand new front section in my garage..and...after shaking it, then rolling it on the floor, I must report that it is noise free.

 

Well, I really shouldn't complain much, I did get quite a deal on it. I guess I should give Stratmosphere a call to see if I can get a warranty replacement on a 2nd hand resonator . Thanks for the reponse

Anyhow, I have two additional question I might as well ask. (Sorry for the long post)

1. What type of gasket does the new system come with for the flanged connections. I ordered the OEM gaskets but am not sure how well they will work on the rear flange. I would hope so, the OEM gasket (it's metallic, btw) works just fine on the front flange. I am currently running without a rear flange gasket (substantial air leakage ).

2. I used the metal spacers between the hangers on the back and the unibody as suggested in other threads so the pipes don't touch the rear valence, but I have had to re-tighten them once already, with less than one week of use, since the bolts were loosening up and causing the spacers to rattle. Has anyone had the same experience? I didn't use lock-tite , so I plan to add it to the rear hangers when I install the rear gasket.

Apart from these small issues, I LOVE the Milltek . It is actually slightly louder than I expected, guess I am not a fan of loud exhausts...