Has anybody seen INSIDE a TDI's catalytic converter?

M

mickey

Guest
Has anybody seen INSIDE a TDI\'s catalytic converter?

Well?

Is it a "straight through" kind of thing...nothing but daylight on the other side?

Or do the exhaust gases actually have to go through a bunch of "stuff"?

The reason I ask is, I'm curious whether mine is plugged up from all the oil and crap from my turbo failure. Raw motor oil was actually dripping from the tailpipe, and the car smoked like crazy for an hour after I started up the new engine.

I don't want to go to the trouble of taking out the cat for "inspection" (
) if it can't be plugged up in the first place.

What's it like in there?

-mickey
 

The Ripster

Veteran Member
Joined
Sep 4, 1999
Location
UP of Michigan
TDI
None at this time
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

It is like a wood stove catalyst honey comb that you can see through, straight thru, but very fine.
If plugged, and going off road racing, you can break it into chunks and it all falls out, leaving a hollow converter. Lots of turbo whine then, and the true smell comes right through.
 

dzljet

Veteran Member
Joined
Jan 6, 2002
Location
TEXAS
TDI
00 Jetta
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Shoot Ric W an e-mail, didn't he do some finger swab test to prove there was no black in his cat as a testament to how low grade fuel and lugging were perfectly healthy habits to follow.


Or was that Pete???


You know what I've done to not worry about it is just wrapped that bad boy up in a blanket. I mean I put thermal wrap around it to keep the gasses hotter and prevent that sooting up. I live in a fairly dry environment so I don't have to worry so much about wet eating up cat, a better choice for you might be to find a place that does ceramic coatings.
 

MOGolf

Top Post Dawg
Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

I had a cat plug up on a gasser at 102,000. That engine had enough exhaust pressure that it just blew the guts of the cat apart when I started it up once. Very loud bang (like a bomb going off), then the engine ran a lot better. Found fine fragments of cat gut throughout the rest of the exhaust system with a few large chunks left in the cat. Couldn't dispose of the remains in the garbage either as the "precious" metals were considered hazardous waste. Had to take it to a metals recycler.

The generic cat replacement was just as the Ripster described. You could see through it, though it was like looking through several screen windows placed back-to-back and not perfectly aligned.

Then the vehicle was recalled for faulty O2 sensor 3000 miles later.
 
S

SkyPup

Guest
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

The cat construction is just like Ripster stated.

It is comprised of a ceramic honeycomb laced with tiny slivers of wire made of elemental palladium, rhodium, or platnium. It is very fragile and cracks apart easily. The 55mm diameter of the A4 cats is 10% larger than the 50mm dia. of the A3's.

The only way it will get clogged is if you idle alot or lug alot not running up to 3,000 or so between shifts, thus not allowing it to reach the light off temp of approx 450*F. The turbo actually inhibits the catalysis since it takes a considerable amount of heat out of the exhaut making it more difficult to light off. Once you reach 450*F though, with the great excess of unburned oxygen in diesel exhaust, the carbon residues are catalytically burned with ease. Cruising at 60-70 is totally adequate for lighting and maintaining the catalyst.

Short shifting ala Ric style, idling, and really bad rotgut diesel fuel are what clogs the cat.
 

LIVE4SPD

Veteran Member
Joined
Jun 2, 1999
Location
Fargo ND, USA
TDI
used to have a 99 TDI Jetta
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

So what are you going to do Mickey? My downpipe is currently full of oil so I can only assume the cat is too. Maybe it's easier to have it cut off?

Is the cat acting as a resonator as well? Just curious because if I hack it off I don't want some drowning noise on the highway.
 

PackRat

Veteran Member
Joined
Apr 14, 2002
Location
Las Cruces, NM
TDI
1998 A3 Jetta TDI
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Originally posted by SkyPup:
The cat construction is just like Ripster stated.

It is comprised of a ceramic honeycomb laced with tiny slivers of wire made of elemental palladium, rhodium, or platnium. It is very fragile and cracks apart easily. The 55mm diameter of the A4 cats is 10% larger than the 50mm dia. of the A3's.

The only way it will get clogged is if you idle alot or lug alot not running up to 3,000 or so between shifts, thus not allowing it to reach the light off temp of approx 450*F. The turbo actually inhibits the catalysis since it takes a considerable amount of heat out of the exhaut making it more difficult to light off. Once you reach 450*F though, with the great excess of unburned oxygen in diesel exhaust, the carbon residues are catalytically burned with ease. Cruising at 60-70 is totally adequate for lighting and maintaining the catalyst.

Short shifting ala Ric style, idling, and really bad rotgut diesel fuel are what clogs the cat.
<font size="2" face="Verdana, Helvetica, sans-serif">So no worries with my 3k shifting an 80 mph cruising speeds!
 

jmur

Veteran Member
Joined
May 10, 2002
Location
CT
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

So no worries with my 3k shifting an 80 mph cruising speeds!
<font size="2" face="Verdana, Helvetica, sans-serif">Might not work in Connecticut, cat would stay clean but glovebox will clog up with tickets.
 

weedeater

Top Post Dawg
Joined
Mar 17, 2001
Location
Reston, VA
TDI
Jetta, 2001, Baltic Green
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

If I remember your described driving style, running hot will not be a problem.
 

Deception

Veteran Member
Joined
May 24, 2001
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Originally posted by ZuberSpeed:
why do u need a cat?

cant u get the TT DP with no cat?
<font size="2" face="Verdana, Helvetica, sans-serif">Emissions reasons.


I'm not sure if it's the same for the TDI, but if you remove the cat on a VR6 or 1.8T, you'll get a Check Engine Light.
 

smokin'

Veteran Member
Joined
Aug 10, 2002
Location
Tampa, FL USA
TDI
2002 Jetta GLS, Black
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Newer gassers with the OBDII system have Oxygen sensors before and after the cat. That is why they will throw the CEL. I don't know if diesels are the same.
 
M

mickey

Guest
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

There are no oxygen sensors on a diesel, since the Air/Fuel ratio is continuously variable. The sensors would provide data, but the data would be meaningless.

A TDI's computer has no way of knowing whether you have a catalyst or not.

-mickey
 
M

mickey

Guest
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

I think I'll take it out this weekend and "examine" it. Hopefully, all that fragile ceramic won't accidentally fall out in little pieces. That would suck.

-mickey

p.s. Seriously...if it's obviously not restrictive, I'll leave it alone. I wouldn't try to defeat it without a reason. (And if it's plugged up, it doesn't do its job anyway.)

If it's messed up, though...I guess I'll have to stay "off road" from now on.
 

Deception

Veteran Member
Joined
May 24, 2001
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

That's another new thing I learned.


So if one was to remove the cat for "off road purposes", would the exhaust stink a lot more?
 

The Ripster

Veteran Member
Joined
Sep 4, 1999
Location
UP of Michigan
TDI
None at this time
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Yes, if you consider diesel smell offensive, many like it.
 

remmuh

New member
Joined
Oct 27, 2002
Location
Lakeside, CA
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

My '96 Hummer has no cat and no Muffler, and it smells really sweet, and sounds awsome... Yeah "off-road" use only... too bad they don't check the emissions on Diesels, at least here in Comifornia.
 
M

mickey

Guest
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

I think the exhaust would smell "different", not necessarily "more."

The TDI's catalyst is just a hycrocarbon catalyst. Its job is to reduce the levels of unburned HCs. There aren't many of those to begin with, if your car is running right. That's why we get 50 mpg.

-mickey
 

konigderheb

Member
Joined
Oct 30, 2002
Location
Richmond, VA
TDI
GL 2001. Reflex Silver
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

why don't y'all just punch the stupid thing out/buy straight-thrus, and not worry about it? mine works just fine with a punched cat, and all the stupid soccer moms get pissed
 

Deception

Veteran Member
Joined
May 24, 2001
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Originally posted by konigderheb:
why don't y'all just punch the stupid thing out/buy straight-thrus, and not worry about it? mine works just fine with a punched cat, and all the stupid soccer moms get pissed
<font size="2" face="Verdana, Helvetica, sans-serif">Do you have emissions testing in your area?

I was thinking about removing the cat, and storing it in my garage. I could get a stainless straight piece of pipe and add some flanges to the setup so that the cat can be easily re-installed prior to my emissions test. (I won't be needing to do an emissions test for another 2.5 years though).

[ October 30, 2002, 20:14: Message edited by: Deception ]
 

ZuberSpeed

Veteran Member
Joined
May 16, 2002
Location
Ontario
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

hey deception, im just getting the TT DP for the TDI

its 2.5'' downpipe w/ no cat, i think i spoke to you about this..

icq me if u need info on it
 

Gary Miyakawa

Admin Emeritus
Joined
Feb 24, 1999
Location
Roswell, Ga
TDI
1998 NB TDI
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Fair warning on the TT DP... The top, forward bolt is a REAL PITA to get tight...

Gary M
 

texbik

Member
Joined
Aug 25, 2002
Location
Austin TX area
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

If running flat out will get your cat cleaned, my cat should be squeaky clean. Two weeks ago I ran flat out for two straight hours between Roswell, NM and Santa Fe. Never got below 85 and got up to 105 down one long hill. The best thing is that I got 45mpg!
 

Deception

Veteran Member
Joined
May 24, 2001
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

Hey Zuber, I heard of the TT 2.5" downpipe, but it might be easier if I cut the cat off and used a flanged piece of straight pipe so the cat can be interchanged easily? The cat is worth like $1000 so I don't want to mess around with it.
 

Charlie2

Active member
Joined
Jul 1, 2002
Location
chicago
Re: Has anybody seen INSIDE a TDI\'s catalytic converter?

My turbo also went (at 77,000 miles), oil filled up the cat and exhaust, after repair it took a week to burn off the oil, very smokey. Now I notice a diesel odor (well bio-diesel now) so I'm wondering if the cat is not functioning anymore. Drove SwimmerDave's new NB and it has zero smell from the tailpipe, he's running B20, I'm running B50 and I have a 96 Passat. Any opinions? And if the cat is trashed, how much to fix, since not only to I care about Chicago's air but I don't like to smell the exhaust when at a stop light even if its mostly veggie oil.
 
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