VW TDI forum, Audi, Porsche, and Chevy Cruze Diesel forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
I think my Catalytic converter may be clogged is there any way to test whether it is? If not, can I clean it out manually or punch it out somehow?

Thanks,
 

·
Premium Member
Joined
·
9,661 Posts
Welcome to the forum. welcometomyturbodies

Well I'm not sure that you can test for a blocked exhaust on a diesel as you can on a petrol engine.

On a petrol engine you would use a vacuum gauge plugged into the inlet manifold to measure the manifold vacuum then you would increase the revs to about 2000-2500rpm and the vacuum should remain constant, if the vacuum drops then the exhaust is blocked/blocking/restricted.

With a diesel there is no direct manifold vacuum so this would be difficult to check. You could try it as you have nothing to loose.

Oxidising Catalytic Converter
 

·
Registered
Joined
·
90 Posts
Try unbolting the exhaust at the turbo. That will bypass the cat. You can punch it out but exhaust shops pay big money for cats because of the precious metals inside it. Personally I'd replace it if it's bad since the cat filters emissions.
 

·
Premium Member
Joined
·
5,942 Posts
The diesel cars aren't worth as much as the petrol cars as they're more of a particle filter rather than gas emmission filter so don't have all the precious metal in them apparently but yeh just unbolt it from the turbo and try it, there should also be a decent puff from the tail pipe when the engine's revved up, if the exhaust is choked it's like an old man with half a lung.:)


welcometomyturbodies
 

·
Premium Member
Joined
·
736 Posts
Welcome to the forum. welcometomyturbodies

Well I'm not sure that you can test for a blocked exhaust on a diesel as you can on a petrol engine.

On a petrol engine you would use a vacuum gauge plugged into the inlet manifold to measure the manifold vacuum then you would increase the revs to about 2000-2500rpm and the vacuum should remain constant, if the vacuum drops then the exhaust is blocked/blocking/restricted.

With a diesel there is no direct manifold vacuum so this would be difficult to check. You could try it as you have nothing to loose.

Oxidising Catalytic Converter

there is special exhaust gauge (it is basically an air gauge) so you drill a small hole before cat connect the gauge and measure back pressure. It should be less than 2psi on petrol engine, not sure for diesels but believe it should not be any different. At the end, the drilled hole is closed with a rivet. Or you can use laser temperature measuring gun and measure temperature before cat and after cat. If the temperature before cat hotter by 150 deg or more, then cat is restricted and hot exhaust gasses are not escaping on time.
 

·
Premium Member
Joined
·
9,661 Posts
I was saying that you measure vacuum not pressure. I'm not sure what pressure readings you should see you would have to google it it.

Again measuring temperature even though it can be done you still need figures to compare it with.

What makes you think the catalytic converter is blocked. loss of power?

As suggested a quick way would be disconnect the pipe but you would still need pressure/vaucuum readings to compare before and after.

Do you have access to VAG-COM?

thestoic22 hasn't been back since.
 
1 - 6 of 6 Posts
Top