Catalyst problem?

[belfry]

I have recently had a replacement engine fitted to my 2003 Cayenne S. Shortly after getting the car back the oil cooler failed and coolant was passing through the system and out of the exhaust as steam!

A new oil cooler has been fitted. However, the car feels sluggish and the fuel consumption is poor. I have cleaned the MAF x 2 and checked the coils (which were replaced recently).

Am I looking at a failed or clogged catalytic convertor? And if so, what are my options about fixing it?

Many thanks

[belfry]

I have discovered that the 2003 Cayenne S has FOUR catalytic convertors! OMG what is this going to cost me?

Anyone? It's a beautiful morning but I'm feeling depressed.

[anonymous-user]

Probably a silly question but how does coolant get into the exhaust from a faulty oil cooler?

[belfry]

TBH I thought that it was the head gasket but the garage said the it was the oil cooler or oil separator. Symptoms were coolant loss and steam coming out of exhausts.

No coolant loss now, but clogged catalyst type symptoms.

[Rockster]

belfry said:

I have recently had a replacement engine fitted to my 2003 Cayenne S. Shortly after getting the car back the oil cooler failed and coolant was passing through the system and out of the exhaust as steam!

A new oil cooler has been fitted. However, the car feels sluggish and the fuel consumption is poor. I have cleaned the MAF x 2 and checked the coils (which were replaced recently).

Am I looking at a failed or clogged catalytic convertor? And if so, what are my options about fixing it?

Many thanks

No CEL? I would think if a converter were plugged or had failed there'd be a CEL.

So, I'm not sure the symptoms are from a plugged or failed converter.

What would they be from? Well, first this...I'm having a problem understanding how coolant could end up in the combustion chambers and the exhaust and converters from a failed oil cooler. I can see coolant in the oil. Or oil in the coolant. But coolant (or oil) in the combustion chambers?...

So I'm not sure what the symptoms are caused by. There is no CEL with say misfire codes with it which would be expected if the engine were suffering from reduced output, significant reduced output.

The only time in recent memory I encountered a vehicle with what proved to be reduced output -- only recognized as such when the output was improved and then I realized prior the output had been reduced or diminished -- was a 2011 Infiniti EX35 that is my sister's and had been sitting so long the gas had gone stale.

When I started driving it - after about 6 months of inactivity and gasoline that old or older -- I felt the engine was a bit flat but being unfamiliar with the car I just assumed it was a bit of a dog.

But after driving the car enough to burn through the tank of stale gasoline, after a fill up with fresh gasoline, the engine's transformation for the better was rather striking.

I do not know the history of your car but could it be just stale gasoline?

Or something blocking the intake? If the car sat long enough -- and it doesn't take as long as one might think -- mice can have built a nest in the intake box.

Before you opt to replace the converters given their cost I think you need some hard facts to go on. And at the top of the list is what is going on, exactly.

Thus I think you need to get the vehicle to a qualified shop for a proper diagnosis of the symptoms. The pieces, at least to me, do not quite fit.

[m030]

belfry said:

I have discovered that the 2003 Cayenne S has FOUR catalytic convertors! OMG what is this going to cost me?

The primary pair of cats are the important ones as the lambda sensors are before and after these cats.
The secondary cats can be deleted , have them gutted or replace them with bypass tubes.

I rather think that it is one or more lambda sensors that failed due to the water/oil in the exhaust.