Burning 4 quarts of oil

Okay my 2006 nissan xterra has been burning about 4 quarts of oil about every 160 miles. This started after my left side cat went out so I replaced both then I replaced all spark plugs and all six spark plugs were smashed in on the end not sure what makes that happen(ive sence checked the spark plugs I changed and non of them have bent in again) after all that happened my oil pressure gauge was reading low pressure so I checked the oil it was 4 quarts low so I filled it up and checked the oil for any milky look to it and it looked normal I did an oil change the next day when I drove home 160 mile and I again was about 4 quarts low. I’ve also left my car running in the drive way for around an hour no oil has leaked in the driveway and there is no oil on my undercarriage at all its spotless the exhaust isn’t a blue color or blowing smoke. can anybody help

If you are burning 4 qt of oil that fast then you need a new engine or to rebuilt this one. The Cat converter probably went out due to too much burnt oil.

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It started burning oil long before the cat went out, that’s why the cat went out.
Rings or valve seals would be my guess, a compression test is needed.

And I would probably change the PCV valve they’re cheap.

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Did you compare the old plugs with the new ones? Were the old plugs LONGER in the threaded area than the new ones? THAT will smash the electrodes flat and may be the reason for your oil burning. In other words, the pistons have been damaged by the incorrect spark plug poking so far into the cylinder that they contacted he pistons and now your engine is burning LOTS of oil.

Coincidence? I don’t think so!

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@Mustangman - This sounds like the most logical explanation.

The Nissan V6 engines are extremely well made and if properly maintained should last several hundred thousand miles. 4-quarts ever 160 miles…you need a new engine.

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It has been claimed that fragments from a crumbling converter core can be drawn into an engine, causing cylinder wall abrasion and oil consumption.
Here’s one case:

https://www.nissanclub.com/forums/2002-2006-nissan-altima-discussion-2-5-3-5/220988-2002-altima-2-5s-68k-engine-replacement.html

XTerra of that year has at least a foot length from the heads exit ports to the first cat, it’s not that years of Altima having cat sitting right on the exit port

one way or another that engine is shot and needs replacement, question is if new cats are already damaged after pumping so much oil through them

My old Corvair could burn 4 quarts of in less than 100 miles. Not bragging…just a fact.

I can recall a customer pulling into the gas station in his Corvair, and telling me… “Check the gas and fill the oil”. When I attempted to correct his apparent mistake, he replied, “This is a Corvair, son, and I meant it exactly as I said it”.

Was that you, Missileman?
:astonished: