2019 pathfinder smoking

[soopanoob]

hello, 2019 pathfinder 3.5L. smoking from tailpipe intermittent. sometimes start up, sometimes hard accel, sometimes on turns with medium accel. search forum and found nothing related. mild surprise because previous internet searches show build up in valve cover.

when bought from a (bmw) dealer (bastards!), the carfax shows last oil change was over a year. reading about the oil sludge issue, i have been changing the oil ~2-3k since owned (0-20, fram xtra or tough gard filters). because of the blue/white smoke, i have been topping off with atf (have extra from work) to help break up sludge until next oil change. also, i have replaced the pcv valve (aftermarket). build up so bad that one plug fouled and i just cleaned it and am using injector cleaner to help clean combustion chamber. there is some sludge inside oil fill cap, but seems minimal. no milky.

questions: 1. anyone that has experienced this, is there a fix?

2. for issue being intermittent, is there anything else i should look out for to correct condition.

suddenly, i am unable to think of the other questions i had. more later, i guess. thanks for all the help!

[VStar650CL]

Once it's sludged the top end usually wipes out, and there's no good fix if that's the case. Chances are the little J-shaped hose connecting the PCV Valve to the plenum is collapsed and nobody spotted it. That's an infamous (and sadly common) condition on VQ35's in Z52 Muranos and R52 Pathies. No amount of fresh oil will prevent it, it's a part failure and not a maintenance problem. If you've caught it early enough then a new hose and an engine flush may salvage the situation. If it still smokes after that then the engine is done.

[soopanoob]

thank you for the reply. curious, what 'wipes out' in the top end?

is lack of oil changes the only failure in the build up issue?

the fresh oil was just to help wash away anything. going to inspect/replace the hose and seafoam then see what happens.

thanks for your time.

[VStar650CL]

When that hose collapses, the PCV can no longer evacuate the crankcase. That causes sludge to rapidly build up in the top end, eventually blocking the oil returns and strangling the flow. In turn, that eventually traps enough oil in the rockers to deprive the jets which oil the rods and pistons. So if it goes far enough, the whole engine wipes out and not just the top end. Just clearing out the sludge won't fix the underlying problem, which is lack of PCV scavenging. If the sludge is very bad the whole PCV system needs to be cleaned out, usually entailing new rocker covers because the baffles in the old ones are clotted.

[VStar650CL]

PS - Lack of fresh oil basically has nothing to do with it, although of course bad maintenance will accelerate the damage. The problem is a clogged waste disposal system for the crankcase. When blowby can't be evacuated, terrible things happen.

[soopanoob]

thank you for the help.