Hi all,

My mini has 17% pulley, exhaust (Decatted), Header & tuned. There seem to be this type of "glitter" on the rear end of the car, its more so noticeable when the sun reflects on it and mostly visible on the back window. It has to be coming from the exhaust, also when i rub my finger across the back, it seems slightly oily, very slightly, nothing hectic . What is this??

 

Maybe your car has been cheating on you and going to strip clubs without you? Stripper glitter on a MINI.
Now seriously....it is probably just road-spray from someone else's leak off the road, buttttttttttttttttt..............
I'd double check you engine oil level .....ASAP. There have been a lot of leaks lately....sometimes from locations very hard to see, and it leaks in ways that generally does not form big spots on your driveway, or smoke. Oil (a very thick, almost gelatinous consistency) is also used in several places in the MINI for vibration dampening....engine mount/vibration damper, and in a few suspension locations....maybe one is leaking, shirting, and spraying back a bit?? Very unlikely.....the stuff is thick....but often overlooked when looking for leaks.

 

Oil level still seems fine and its not the first time ive notice this, it happens all the time. I can wash the car..drive it a bit, it would appear again. The "glitter" is a silvery sort of colour that can only be seen when the sun reflects on the rear window.

 

I have had the same thing happen. Its the muffler packing.

 

cant be, I had the complete exhaust system (bought it brand new) fitted a few months ago only.

 

new exhaust systems have new muffler packing (and thus more to lose) -- think of it like an equilibrium equation, if there is more packing there (as in a new muffler), more is going to puff out.

 

Do you ever use drive through car washs ever?

 

My guess: it's caused by your brakes. I first noticed this on my black GTI-VR6. As brake pad wear, bit of them are made into dust and that floats around in the air stream under the car. A hatchback like the MINI or my old Golf has a big negative air pocket at the rear causing the brake residue to attach itself to the rear. Using a more aggressive brake pad only makes the issue more noticeable.

 

excuse my ignorance, but can someone explain muffler packing?

 

...think a combination of steelwool and household insulation.

 

The packing material is a mesh or fibrous material which is typically present within the baffles of a muffler. It does a number of things, some of which are to serve as a pressure boundary which slows the exhaust gases, allow gases to cool down, and break resonance patterns (pressure waves) which can form in bare baffled or unbaffled systems.

Since they have a much higher surface area to volume ratio than the rest of the muffler, they are typically the part that is most subject to pressure / shearing forces (and thus the first part of the muffler to break down).

They're typically made of metal / ceramic fibers which appear "shiny" or "sparkly" when broken down and exposed to sunlight.

Some people claim that it is part of the muffler "burn in", but what that's really saying is that you run them until there is not a significant amount of packing left to be puffed out of the tailpipe (this is why mufflers tend to get louder and pick up resonance over time).

 

I used to go through cats and mufflers on a regular basis on the autobahn until I wised up and put in a straight pipe system, lol

 

I thought that "stuff" was only used in cheap "glass Pack" mufflers like "Cherry Bomb" type mufflers that tuners put on Honda that make them sound like a leaf-blower or a weedwacker!!
Maybe it is just Silica in the sand on the roads that is getting ground down and getting stuck to your dirty butt?! That can have a bit of shinny sheen to it, kind of like glass or have a bit of a luster to it.
Brake dust....possible I guess.....heck anything that means you car is not broken or is breaking is good right!!

 

What kind of brake pads are you using?

 

I can't see brake pads doing that. I have first hand experience with 2 exhaust systems doing it for the first 1k miles. Excess SS muffler packing being tossed up into the negative pressure area that also causes the DIRTY BOOT syndrome.

 

I was just going to ask about this as well. I just recently installed a cat-back exhaust on my Mini and now the back is covered in glitter. It has to be from the exhaust because it never would do this before I had the exhaust installed.

 

Machupo, good clear explanation..Makes sense.. thanks

 

Ya i get it to, and only really noticed it when i out the new exhaust on, so my bet is thats what it is, it has lessened with time.

 

I get it as well w/ same mods as you...Pretty sure b/c of us having no cat, its carbon coming from the exhaust. As you notice, the back of you MINI prolly gets dirty pretty quick too huh!?! The way the exhaust leaves the exhaust tip, must create some sort of "whirl-wind" or something back there...But pretty sure its carbon from the exhaust that would normally be burnt up in the cat that was my conclusion that I drew from my MINI!!!