Holden 6VE1 Cat Convertor Failure

Member 1

We have been involved in two factory engine failures from this model Rodeo. The first was clearly gravel entering via a split gasket at the intake manifold. This led to rapid bore wear and eventual oil consumption and then to a siezed crank at 60,000kms.
The current one had been diagnosed as noisey valve guides causing the noise in the driver’s side head. I didn,t get to hear it but failed to find the problem in the head. However, whilst at the dealer’s shop, I showed them the vertical scoring up cyl # 3. To me it indicated a siezure.
This dealer reports having done several engines under factory warranty recently. All DUE TO FAILURES OF THE CAT CONVERTORS. They found large amounts of material in the intake manifold. They have a new factory engine going into this one under warranty.
Whilst I can’t accept their explanation, from what I saw, I suggest that we all watch this engine model for when it comes in for a reco.  Meanwhile I will try to get a sample of this material.

Member 2
I have been involved with one just like the one you described, this week.  Received block, piston and crank.  Bearings looked perfect, crank journal missing 4 thou of each journal &  2 thou even wear in bores.  Initial reaction – contaminated oil. I asked them to send me the heads because of the mystery, stripped and inspected them, found worn stems on inlet valves. All this information passed back to Holden Warranty man through dealer. From conversations passed backwards and forwards it was clear that Holden knew more than they were telling us.  Dealer was told that he would be given new engine even though vehicle out of warranty by time. Dealer told to change both cats.  Dealer found cats were completely empty. Intake ducting was checked for dusting and I was told it looked perfect.  On cleaning the plenum to go on new motor, mechanic found lots of debris which apparently is the missing converter matrix. Dealer tells me that there is a path for this debris material to make its way into oil.