Hi all,

I have a 2006 Nissan Pathfinder with about 130k miles on it. If the truck idles or sits in traffic, you can smell burning oil either in the engine bay or through the air vents in the cabin. The smell clears up when you get moving. The exhaust smells normal, and there are no abnormal engine noises and no oil consumption that I've noticed. I run full synthetic (Valvoline high mileage w/maxlife), changed every 5k miles.

I think the issue is the head gaskets are failing. I see moisture on the exhaust heatshield and the block, which is almost certainly oil. PIctures attached (they aren't great, sorry!) Or hopefully, it's just the valve seals?

Thoughts?

A leaking head gasket would not really give u burning oil smell but or even blowby past the rings wouldnt at least not in front of the car.
And neither are terribly common with these engines.

Like a leak near the oil filter that would sometimes spread oil under the hood and could give me a burning oil smell.
It could also be one of the engine seals which do happen sometimes on these engines (albeit usually after 150k and more).

I'm not too familiar with the VQ40 so the only thing I recognize is the exhaust manifold heatshield. If that bolt with dark black oil residue is a valve cover bolt, then your issue is either loose bolts or needs a new valve cover gasket.

Those are your valve cover gaskets! I just changed mine out about a year ago. You have to take off the air intake to get at them, as well as, disconnect the wiring harness. This video is very helpful. https://www.youtube.com/watch?v=ftHfzvl48H4
It does take 6+ hours to complete this job and you might as well do the spark plugs while you are in there.

^^I agree^^ Definitely leaking valve cover gaskets. At 165K., it might be too early for spark plugs, assuming they were done at the scheduled 105K interval. I would get new gaskets for the intake plenum and if you ever thought about installing an XTP plenum spacer and haven't done so yet, now would be the time!

Thanks all! Does anyone have a downloadable copy of the factory shop manual?

AndrewT wrote: ↑

Wed Feb 24, 2021 8:27 pm

Thanks all! Does anyone have a downloadable copy of the factory shop manual?

Yes, Nico (the host of this and other Nissan forums) has a page for that:
https://www.nicoclub.com/nissan-service-manuals

Late to this party but +1 on the head gaskets. That's exactly what your issue is, and what I just fixed on mine a couple months ago. Last of my persistent oil leaks, the smell is gone!

ShipFixer wrote: ↑

Thu Feb 25, 2021 10:58 pm

Late to this party but +1 on the head gaskets. That's exactly what your issue is, and what I just fixed on mine a couple months ago. Last of my persistent oil leaks, the smell is gone!

How can you say that head gaskets is exactly what his issue is when the oil is clearly seen leaking at the corner of the valve cover and residual oil is on the top of the exhaust manifold heat shield, which is far above where the head gasket is on the engine?

smj999smj wrote: ↑

Mon Mar 01, 2021 12:24 am

ShipFixer wrote: ↑

Thu Feb 25, 2021 10:58 pm

Late to this party but +1 on the head gaskets. That's exactly what your issue is, and what I just fixed on mine a couple months ago. Last of my persistent oil leaks, the smell is gone!

How can you say that head gaskets is exactly what his issue is when the oil is clearly seen leaking at the corner of the valve cover and residual oil is on the top of the exhaust manifold heat shield, which is far above where the head gasket is on the engine?

Argh...I meant valve covers...

OK, will give you a mulligan.

I didn't post about my valve cover replacement a few months ago, but it was one of those things I was putting off, and putting off, then putting off some more while they collected dust in my apartment in VA. Then I moved to CA and still didn't get around to it...

So shortly after I got here I went surfing with one of my friends who just got a Tesla Y as his surfboard carrier. He was showing off flooring it from every light, so I gave the Pathfinder all of the gas pedal for a bunch of launches for the first time in...well, ever! Never felt like the Pathfinder was outgunned as an SUV until then. Of course later, lots and lots of oil smell. The passenger side where the leak is usually the worst/shows up the first was apparently some kind of spray-gun affair, a lot of the wiring, tubing, and aux stuff on that side had a pretty good coat after that. Plenty of dripping all the way down to my new garage floor too. Then I had an unrelated ignition coil go bad so figured it was finally time to do the un-fun business of valve cover replacement.

Some stuff that came up with mine - needed to replace the extra gasket under the plenum spacer as it came apart when I removed it (cut one out of gasket material using the pieces of the original), and procured a couple extra valve cover bolts because now there's one hiding somewhere under my engine, maybe never to emerge. Worth ordering a couple extra with the covers just in case as they're something like $1, but my local dealer happened to have them.

Short version of that story? So, yeah...I want a Tesla 3 next to my Pathfinder to haul (short) surfboards