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This Is pretty much what the local Nissan dealer has has said to me, the main difference is they are replacing the motor and cat under warranty. They said the reason for the engine swap was because due to the Cat failing it caused some of the internal mat to be pushed back into the motor causing it to burn oil. I just turned 125,000 km and the warranty is good till 130,000 km so I'm just glad it happened now.
 

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Discussion Starter #22
Burning oil would mean the piston rings and hence compression were compromised. In your case it justifies the replacement of the engine block. Its a bummer that this can happen to the VQ35DE;1 its best to keep the cats happy. At least in your case it was still covered under warranty. In my case, no oil burn nor compression loss was found, which I'm very grateful for.
 

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njjoe said:
WG-

Are you serious?!? The dealer claimed your engine inhaled the stuffing from the cats?!? That is total BULLSH*T!!!!

The catalytic converters are downstream of the engine. How could the internal honeycomb structure possibly flow upstream against the exhaust flow and enter the engine? What do they think, that you have salmon in the catalytic converter?!?

-njjoe
I realize this is an old post but I wanted to resurrect it to correct an error so it is as accurate as possible in case someone searches for the information.

I incorrectly stated that it was impossible for the MO's engine to ingest material from the cats. Even after hfelknor proved me wrong I still had trouble grasping reality (sorry, Homer, I will not doubt you again ;) ),

As it turns out the VQ's variable valve timing is configured to keep the exhaust valves open for a short duration during the intake stroke. This enables a small amount of burnt exhaust gases to be drawn into the cylinders. With this set-up the VQ operates as if it had an EGR valve. The variable valve timing eliminates the need for the trouble-prone EGR valve.

If the engine is not operating correctly and the precats overheat it is possible for them to mechanically fail and for the substrate to be drawn into the cylinders resulting in catastrophic damage to the engine internals.

-njoe
 

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"(sorry, Homer, I will not doubt you again )"

No, PLEASE doubt me again.
That's how we keep each other accurate.

And besides I have shot from the lip on other things through the years only to have you save my bacon.

Homer
 

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I own a 05 Altma. 3.5 V6 with a 5 speed. Had clutch replaced and the mechanic told to get rid of it. 195,000. I taken care of car with service at dealership. The mechanic said that the converter guts can be sucked into engine. Car runs good and check engine light is on and diagnostic says it the c.convertor. How concerned should it be? Take off the c.c.
 

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Replace the cat before too many miles are driven with the engine light on. The longer you wait, the more likely that the above conditions mentioned will happen to your engine.

Have a good day.
 

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I own a 05 Altma. 3.5 V6 with a 5 speed. Had clutch replaced and the mechanic told to get rid of it. 195,000. I taken care of car with service at dealership. The mechanic said that the converter guts can be sucked into engine. Car runs good and check engine light is on and diagnostic says it the c.convertor. How concerned should it be? Take off the c.c.
Please read the entire thread, but note that it was determined that the cat material can be pulled back into the cylinders. If it doesn't damage the cylinder bores, you're lucky.

I'm not sure how many cats the Altima has, but replace all of them if there are more than one. The most critical to prevent engine damage in the Murano are the cats nearest the engine, one per exhaust bank.
 
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