Decat blowing

[jack_davey]

Fitted a decat yesterday, cant seem to get it to stop blowing at the join with the centre section, is this normal?
My cat didnt blow when that was on there.

 

[Curley]

I doubt blowing is normal!

What decat is it btw?

 

[Henry]

try sealing it with something like Loctite 5920 (copper based RTV sealant - Halfords)

 

[lee131]

ones brand new stainless ones old rusty steel, try plenty of sealant and 100o steady miles before you rag it

 

[jack_davey]

ones brand new stainless ones old rusty steel, try plenty of sealant and 100o steady miles before you rag it

Nah they're both near new stainless, I have a milltek decat (for the standard system) and a scorpion RS192 cat back section.

I know it's not normal for it to blow, but is it common that they're a bad fit?
I've taken it off 3 times in an effort to sort it out and I still cant get it to stop blowing!

 

[Dan R]

Make sure what ever you do replace the wire cone that fits on the flange where the decat meets the downpipe. If you havent then it will blow like hell. Its expensive tho. Bought 30quid with the bolts which you need too

 

[jack_davey]

Yeah I bought the cat fitting kit from renault, was hideously expensive for a gasket and two bolts!

 

[Henry]

how are the decat and system pipes connected? is it a sleeve or a flange (etc)?

are you using a gasket if it's a flange fitting? and have you tried silicone sealant yet?

 

[Dan R]

Yeah I bought the cat fitting kit from renault, was hideously expensive for a gasket and two bolts!

Thats ok then.yeah it is a complete rip off for a flange and some stupid bolts! Lol

 

[GazM]

they are very hard to seal mate, as said above use pleanty of exhaust sealant. Also make sure the gasket is sitting properly

 

[Andyman]

Cat to centre section should seal very easy. Metal gasket is usually fine without any sealing needed.

Cat to manifold / mesh ring is a different kettle of fish.

I'd be tempted to slacken the centre section off, possible this aint sitting right and throwing the whole system out?

 

[jack_davey]

The manifold to cat join is a bolt together jobbie with a wire gasket, the cat to centre section is a flange type join with a clamp and no gasket.
The decat to centre section is where it's blowing, I think the centre pipe is aligned perfectly to be honest because when I had the catalyser fitted, it fitted perfectly with no blowing at all.

 

[jack_davey]

put the cat back on and it still fits perfectly, no blowing! I've noticed the flange on the decat isnt exactly the same shape as the one on the cat, similar but not the same!

 

[jeremy]

My exhaust blows where the centre pipe and cat meet (flange set-up).

I've take it back to the guy who fitted it 3 times. He looses the clamp, but some Holt Gum Gum around it, tightens it and its ok for a week and then starts blowing again.

I'll grab some of the Loctite stuff from Halfords but do I need some sort of a gasket there too??

 

[Fred@BTM]

silicone son, gungum is crap

 

[jeremy]

Further up they say try Loctite 5920 (copper based RTV sealant). I take it this is the silicone stuff? If not where can I buy it from? I'm in Hall Green so if you can give me some I'll pay ya

 

[Fred@BTM]

pop round later and i'll do it for you, i'll be out working on the V

 

[jeremy]

Nice one Fred. Can you pm me your addy. Just hope it doesn't chuck it down cos the weather don't look great

 

[Fred@BTM]

call me in a bit 07769712624

 

[jeremy]

thanks

 

[Fred@BTM]

edit, s**t i forgot i'm going to pick up a car erm call me in the week!