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[Toledodude1973]

Looking under the Omega 2.6 today i noticed the heat shield outer casing on the cat converter was crusty and some of it is missing,is this a MOT fail . its not blowing and is it an expensive replacement thanks for any help

[Doctor Gollum]

Can be secured with a large stainless jubilee clip or removed completely 

[Nick W]

You'll only ever notice a difference whether it's there or not if it rattles.
So remove them from each cat.


Easy

[Toledodude1973]

so just break them away and no MOTworries

[Alnico Blue]

You'll only ever notice a difference whether it's there or not if it rattles.
So remove them from each cat.


Easy

Nick . . . this "cat rattle" on my 2.6  I have a loudish rattle only when the car is started from cold , meaning overnight cold.  On cold  start up it rattles like hell for about 20 secs then fades completely after about a minute or 2.   This is coming directly from the drivers side cat from  the heatshield area.
I might try & remove the heat shield as it must be this that is causing the rattle.  I'm guessing as  the cat heats up something must be expanding & the rattle stops.

To remove . . . is it a case of just carefully grinding through the welds & the shield will then come away?

Or am I getting this totally wrong & its something in the cat rattling? 

[annihilator]

Depending on how rusted they are you can usually lever them off with a big Screwdriver /bar, however my rattle turned out to be the cats innards which had broken up and needed replacing.

[nellys coupe]

its not an mot faliure so long as its not blowing,

[Nick W]

You'll only ever notice a difference whether it's there or not if it rattles.
So remove them from each cat.


Easy

Nick . . . this "cat rattle" on my 2.6  I have a loudish rattle only when the car is started from cold , meaning overnight cold.  On cold  start up it rattles like hell for about 20 secs then fades completely after about a minute or 2.   This is coming directly from the drivers side cat from  the heatshield area.
I might try & remove the heat shield as it must be this that is causing the rattle.  I'm guessing as  the cat heats up something must be expanding & the rattle stops.

To remove . . . is it a case of just carefully grinding through the welds & the shield will then come away?

Or am I getting this totally wrong & its something in the cat rattling? 

If it's the shields rattling you won't need a grinder, just some stout gloves to prevent you cutting your hands when pull the shield off. Once you've done that, give the cat body a thump with your fist. If that makes it rattle, the cat is knackered and needs to be replaced. They do tend to make a much heavier noise than just rotten shields though.

[Alnico Blue]

Right  . . .tested as follows from cold this morning 

started car   . . .noisy rattle from cat below drivers seat  . . .as soon as I touched the shield below the cat  firmly with a gloved hand  . . .noise stopped instantly  . . .took hand away &  noise started again .

so must be the shield .      Not decided if I will remove it as although annoying  . . .it only lasts for a minute or 2 from a totally cold start 

[Doctor Gollum]

It will fall off in due course... Wait until it rattles when warmed up and remove it.

Wait any longer and the person behind might be claiming off your insurance...

[dave the builder]

It will fall off in due course... Wait until it rattles when warmed up and remove it.

Wait any longer and the person behind might be claiming off your insurance...

how will the car behind prove the part fell off the omega 
our roads are covered in car parts that fall off  ,nearly as many parts as pot holes 

personally, i would wire or hose clamp the heat shields back on ,the sooner the cat gets warm ,sooner it works ,less chance of post cat lambda reading rich 

[Migv6 le Frog Fan]

There is a hell of a lot of heat which comes of cats when the car is running. I would be concerned that binning the heat shields would allow all that heat to damage things under there ? 

[TheBoy]

There is a hell of a lot of heat which comes of cats when the car is running. I would be concerned that binning the heat shields would allow all that heat to damage things under there ? 

My old MV6 lost all its heatshields years and years ago, including the cat ones.  I reckon I drove it in such a way that the exhaust got pretty hot.

Never had an issue.

[cam.in.head]

According to my not test station the shields are now part of the test and if originally fitted should be there at mot time.he said he will fail a car with a shield missing .like someone said earlier just jubilee clamp it secure or re screw the lip if there's any lip available to screw to !.

[Doctor Gollum]

It will fall off in due course... Wait until it rattles when warmed up and remove it.

Wait any longer and the person behind might be claiming off your insurance...

how will the car behind prove the part fell off the omega 
our roads are covered in car parts that fall off  ,nearly as many parts as pot holes 

personally, i would wire or hose clamp the heat shields back on ,the sooner the cat gets warm ,sooner it works ,less chance of post cat lambda reading rich 

Rest assured, if the come through my windscreen, your insurers will be getting a phone call 

[Nick W]

There is a hell of a lot of heat which comes of cats when the car is running. I would be concerned that binning the heat shields would allow all that heat to damage things under there ? 

Mine had none of the exhaust or cat heat shields on it due to age/damage/apathy about refitting them. Worked like that for several years with no problems.


There's a huge chunk of metal under the bonnet that isn't shielded which retains heat for hours

[Bigron]

We never had any such issues before cats had to be fitted - to solve a non-existent problem!
Now, we can't use leaded petrol in cars with cats and so valve stem clearances have to be increased, to the detriment of oil consumption. Once again, lead removal from petrol was unnecessary; but Johnson-Matthey did well out of it.....

Ron.

[biggriffin]

We never had any such issues before cats had to be fitted - to solve a non-existent problem!
Now, we can't use leaded petrol in cars with cats and so valve stem clearances have to be increased, to the detriment of oil consumption. Once again, lead removal from petrol was unnecessary; but Johnson-Matthey did well out of it.....

Ron.

And still are, just go to the plant in Royston, or the warehouse in Bedford.