How much hell can a catalytic converter take?

[Normy]

-One of my other cars is a '97 Jetta GLX with the VR6 engine. Fun ride...when it isn't blowing up!

Well, the latest problem with this car is actually a fairly common one, according to the forums over at VWVortex. This particular VR6 has no distributor- it has 3 double coils and a pretty decent motronic system instead. Normally this would be an improvement in long-term reliability, but in this case, it isn't. The coil pack on this engine is mounted at the end of the front cam, and since it is screwed to the block, it is subject to heating/cooling cycles. 11 years down the road...these heating and cooling cycles have added up and something broke the other day.

Last month I started this car one time. I park the thing in Memphis, 800 miles from my house, and use it when I'm up there for work and have to spend the night there, which is fairly rare but still happens. In November, I only started the car one time- I had a cool schedule which precluded me using the thing. Well, it ran on about 5 cylinders, something that bothered me. I figured water in the gas or maybe a fouled plug. The car is old...

Well, Christmas eve I wound up in Memphis and had to drive the 25 miles to the "crash pad" I keep up there, which is 8 guys renting a house. The car ran fine- except for a few moments at 70 mph when it started to miss. I had it all figured out; condensation in the tank = water in the gas. I planned on buying some Christy Dry-Gas, which normally solves this problem quickly.

Spent X-mas day at the pad; chicken on the grill- hell of a holiday meal! Oh well.

Go to drive to the 7-11 for something: the car runs on 5 cylinders. I return to the house, and pull all the spark plugs. Guess what? I'm not driving a 5 cylinder, I'm driving a four cylinder! Two cylinders aren't firing. I have spare plug wires around, and I change them out. Still the same problem...

And the catalytic converter glows red...

If you have a cat...excessive fuel will burn inside the thing, turning it RED HOT in a hurry. The ceramic structures inside the thing can actually MELT and then it will plug up, destroying the unit and wrecking power and fuel economy.

The VR6 engine has an intake manifold that wraps around the injectors and their rail. You have to do multi-hour surgery on this engine to get at the injectors, so I couldn't pull the connectors on the injectors. That rhymes...

Well, I had to drive the car that night. There were no rental car agencies open, and the 25 mile ride to the airport would have been ridiculously expensive via cab. Since I see [well, hear...] people driving cars with bad misses all the time in Fort Lauderdale, I decided that If I took it easy...considering the cold air, I could probably make it the 25 miles to the airport without melting the cat internals.

That is my question. What does it take to melt a cat? I drove 25 miles in 35 degree F temperatures at a gentle 55 mph on I-40 and I-240, and when I arrived at the parking lot the catalytic converter glowed as shown below [color is strange- it was more orange than purple].

Q: What is enough to kill a cat?

N

[legion]

What is a catalytic converter?

[HardDrive]

I have an idea.

Fix the car.

Then you won't have to find out how much abuse a cat can take.

[carambola]

dude, JB Weld
haven't had to buy another coilpack since

[Normy]

Originally Posted by carambola

dude, JB Weld
haven't had to buy another coilpack since

Hmm. I'm standing here [metaphorically] naked. Where should I put the JB Weld?

[9dreizig]

I wouldn't necessarily jump to conclusions.. Do you have a code reader that you can see what fault it's pulling ?? I've got a 1.8 liter Audi and it was my MAF sensor that screwed up.. It can give all sorts of symptoms

[Normy]

Originally Posted by 9dreizig

I wouldn't necessarily jump to conclusions.. Do you have a code reader that you can see what fault it's pulling ?? I've got a 1.8 liter Audi and it was my MAF sensor that screwed up.. It can give all sorts of symptoms

Thank you for your thoughts!

The problem is...I've already diagnosed the problem, and the glowing pipe is the obvious symptom.

What am I going to do? I bought a new triple coil off of eBay, and I'll install it next month when I get a chance in Memphis.

Again, thank you for your thoughts, and realize it glowed golden orange instead of purple....

I sure hope it isn't melted. That's what I wanted to know when I posted this thread....

N

[beepbeep]

When plugs aren't firing, fuel gets downtown...and lightens up the cat. Change the ignition stuff and hope for the best.

[Hugh R]

The guts are ceramic, it can take an awful lot of heat. We had one glow orange on an ABC Electronic News Gathering Van, those vans with the microwave uplink dish, and after replacing the coil pack it was just fine.

[Normy]

When fuel gets downtown...then all hell breaks loose! I like that.


When gasoline gets into catalytic converters, it results in VILLANOUS temperatures!

N

[beepbeep]

No, really. It can glow but it can survive w/o plugging up the pipe. Precious metals can wear off though leading to bad emissions.

[Normy]

Originally Posted by Hugh R

The guts are ceramic, it can take an awful lot of heat. We had one glow orange on an ABC Electronic News Gathering Van, those vans with the microwave uplink dish, and after replacing the coil pack it was just fine.

Thank you for your opinion. I hope you're right!

I'm hoping I didn't melt the damn thing. The car runs fine with it, and it looks like it would be a huge hassle to change.

N!

[Normy]

Thanx again.

I sure hope I didn't melt the thing.

So...when is a cat overheated/melted? How can you tell, other than a vacuum test and the fact that the car is now running like crap?

N

[carambola]

cover the coilpack in high temp JBweld. get it in every nook and cranny. disconnect the battery or use a vag-com to clear the codes.
that will solve the misfire problem.


as far as the cat, your guess is as good as mine

[Normy]

bump

[sorry in advance...]

[RickM]

If still running like crap after the fix you may want to replace the 02 sensor.