Manifold to cat blowing

[Muhammad]

Hi, I'm hoping someone can help with this. I had a bit of a blow between the manifold and cat so bought a genuine gasket kit and fitted it.

It all fitted nice and easy, when driving with low revs its OK but if i boot it a bit i hear a screeching noise.

When the car is stationary and you rev it there's a lot of movement in the joint even with the new kit in and only a bit of noise. The noise is louder since I've changed the gasket.

Any ideas how i can fix it? Could it be an engine mount allowing too much movement? When i had the mounts checked they seemed fine though.

 

[MRBILLYUK]

Standard 182 exhaust and Cat ? They blow from the olive joint where the Cat meets the centre section . It's a common problem , crap design . You could try a new exhaust clamp and some high temp silicone sealant . Some people do away with the oilve joint altogther and have a piece of tubing welded onto the end of the Cat and have it sleeved to the centre section . When my exhaust is cold and i set off it always blows from there , but as it warms up it must expand as the blowing seems to go away .

 

[Muhammad]

Cheers for that, but i don't think it's blowing from that joint only because its the same noise but louder. The exhaust fitter also thinks its the manifold to cat. I've got a replacement clamp for the joint you're talking about anyway.

 

[MRBILLYUK]

Cheers for that, but i don't think it's blowing from that joint only because its the same noise but louder. The exhaust fitter also thinks its the manifold to cat. I've got a replacement clamp for the joint you're talking about anyway.

If the new manifold to Cat kit has been fitted correctly it shouldn't really blow now . The only way to really tell whereabouts it's blowing from would be to get it up on a ramp or get under the car with the engine running and have a look , put your hand near the joints and feel for it blowing . If you do , be careful not to touch the exhaust or Cat with your hand though as it get's fcukin hot very quickly .

 

[Muhammad]

Lol yeah ill give that a shot, do you think it'll present itself though? Only because the noise happens when im actually driving and isn't really present when stationary

 

[Rob669]

You didn't answer the question of whether or not it's a standard exhaust and cat. If it's not standard (like mine) then like me you'll struggle to get a good fit. I run out of threads on the bolts before it's completely sealed, but I don't mind the noise really. When you say it all fitted nice and easy that made me smile, these are a real pain to fit unless you have an assistant with the arms of Mr Tickle.

 

[Muhammad]

Oh yeah, it's a standard cat with an aftermarket exhaust. To be fair it was on a ramp and i fitted the end nut on by hand then ratchet in one hand with spanner in the other.

So if i got rid of the springs and put longer bolts in (as it was before) it should seal better? Could that cause any problems as it wont flex?

 

[JamesBryan]

Did you fit the fire ring the right way round. One side is flat and the other is curved.

Can't remember which way round it goes, but it should be obvious when you look at it.

 

[Muhammad]

Did you fit the fire ring the right way round. One side is flat and the other is curved.

Can't remember which way round it goes, but it should be obvious when you look at it.

Yup same way the old one came off. Tapered side into the cat

 

[JamesBryan]

Not sure then mate, as it should have fixed it :/

 

[Muhammad]

Bit delayed but its now sorted, put slightly shorter bolts from mani to cat and new clamp from cat to mid with high temp sillicon.

Screech free driving finally! Thanks for the help