Blue smoke at start-up only - intermittently. 2003 Pathy w/ 83K mi.

[vasilko77]

Started up my Pathfinder on Saturday and noticed a plum of blue exhaust smoke. After a few seconds, it went away. First time I've noticed it, haven't seen it yesterday, and will start it up when I get home today to see if it does it again. Was not standing a long time prior to starting on Saturday, maybe 16 hours, since last running. Recently replaced the oil, but not sure if it's due to overfill because this is the first that I've seen it and I replaced the oil a few weeks ago. Otherwise, it drives great with no noticeable loss of power. I have a feeling that it may be the valve seals - anyone have some thoughts on this? Seems a bit early (mileage wise since I have <85K mi.) that this would be the case, but I guess these things do happen. I haven't seen it since, but I know that once it happens once, there's an issue there. I ordered a repair manual online - does anyone have experience doing this? I'm in no way a pro, but know my way around - is this something that I can do in a few hours? Any special tools besides a torque wrench and plug socket?

Thanks in advance for any responses!

[Crazyirish]

It does sound like valve seals, and you will definitely need more than a torque wrench and plug socket.

zerothread?id=257238

This is a KA, so the procedure is different, but it will give you an idea of whats involved.

Worn valve guides could also cause blue smoke on startup.

[vasilko77]

Thanks for the reply - Duh, I was thinking about the valve-cover gasket, not the actual valve seals... Yeah, I'm not going to mess around with that and fear I'm looking at a $3K+ repair. As far as testing to see what the issue is, is there any way of telling without getting in there?

[Pwnin O'Brien]

This sounds more like your issue...

Pathfinder Excessive Oil Consumption

[Chuck Tribolet]

Where did the smoke come from? Exhaust pipe? (most likely valve seals, definitely not valve cover gaskets) Under the hood? (a leak somewhere, find it. But that's unlikely -- it takes a while to get hot enough to smoke) Somewhere else? (need to know where somewhere else is).

The good news is that the seals are not a fatal problem as long as you makesure the oil level stays up. My 'vette has been fogging for mosquitoes every time I fire it up for years.

[vasilko77]

Thanks for the info. I think I'm going to do an oil burn test over the next while to see how much I am burning, since I haven't been checking at oil changes. I don't believe I'm burning a lot of oil, but am not certain.

[vasilko77]

Thanks Chuck - I don't believe that there are any leaks in the engine bay. There is a very very slight amount of oil around the driver side valve cover seal, but I mean it's a really small amount and there has been nothing that has dripped below - it all appears to be clean. Only blue smoke is from the exhaust. I'm just surprised that this has happened as early as it has with <85k mi. and I change every 3k religiously and don't drive it like I stole it...

[Pwnin O'Brien]

Yeah, my '03 has only 67,000 miles and there's a small puff of smoke when I start my car in the morning. I also have a leaky valve cover gasket, but it's extremely small and it's not dripping onto the driveway or anything.

If it does turn out to be the PCV valve sucking oil into the engine, there's actually a pretty easy fix; you can install an inline catch can on the PCV hose which will collect any oil which is getting sucked into the engine. It's pretty cheap and there's a step-by-step how to on NICO. This wont prevent the oil consumption, but it will prevent the engine from burning the oil and prevent the smoke.