Mike1

Just wondered how long the packing is supposed to last in the boxes. My Mongoose system is 14 years old and it sounds like something is rattling inside the back box - no external blow but the rattling annoys me . It is also much louder than when I first had it ( unsurprisingly ). I've been told you can get the last piece of the exhaust separately and just replace that but wondered whether people have just replaced that or the whole system. The structural integrity of the system seems fine ( as you'd expect from stainless ) but just wondered if there's any other option to replacing the system/part of system.
By the way, it's not the hangers or anything knocking on the exhaust

tabetha

It should last indefinitely, but some makes seem to lose the packing.
If it's defo louder it may have lost some packing, these exhaust are absorbtion type exhaust, the gasses are always trying to expand and the sound wave travels into the box/s where it can get through the holes in the perforated tube in the centre of the box into the glass matting, this muffles or silences the sound, but sometimes it blows out, but this is normally when the internals have broken or rotted, so with it being SS shouldn't happen.
In any even it would be much cheaper to cut the box open and re pack it, unless it's a cat rattling ?, just bang the cat to see if it rattles if it has one.
tabetha

YOREVOL

alot of stainless systems use mild steel internals to cut cost. these will corrode just like a normal exhaust.
when on cold start more water is produced by the engine in the form of steam,this condenses in the silencer due to the silencer being cool once the silencer warms up it vapourises and is expelled through the system. as the rear silencer is the last to warm up alot of water collects and corrodes the internals.

Mike1

No, it doesn't have a cat on, just the standard 2wd Mongoose system without a cat. Guess it's just getting old. It's definitely something in the internals of the box, it doesn't seem to be blowing from any joint or box

tabetha

If it's falling apart internally, then obviously it's a shit exhaust design by penny pinchers using most likely mild steel parts inside, this can be repaired easy enough and will likely be a lot cheaper than new.
The exhaust passes precisely the same amount of water regardless of ENGINE(changes with atmo temp) temperature(it comes from the air), it just changes state from water to steam, neither of which should affect a decent system.
tabetha

R4N SS

iTrader: (6)

you need to get it repacked - give the back box a tap and listen if it sounds hollow, then you need to re-pack it.

i have a 3" mongoonse back box if you want it for 50 quid but will need to check it to make sure its not hollow first.

Mike1

Any ideas who offers this repacking service? If no-one, where do you buy the repacking stuff and any ideas how to do it?

R4N SS

iTrader: (6)

no idea mate as i have never had it done

Mike1

This might explain why people end up buying a new box