Occasional smokescreen on startup

[Mike W.]

Title says it all, once in a while, I'll get a full smokescreen on cold start. I mean I'm glad I'm not outside in that smokescreen. Otherwise no apparent smoke. Not necessarily actually cold, but lets say first start of the day when it might be 70F temps. It does drink far more oil than I'd like, a quart every 1000-1500 miles, which seems excessive bordering on extreme for a 140K vehicle. But the smokescreen is on the order of every 2 or 3K miles, or not often at all. Not realizing how involved replacement is, I just bought a new PCV valve, without any other parts, which is uninstalled as of yet, so I suppose that's a possible problem. It's not coolant, it hasn't budged a bit in the 17K I've owned it.

[04pathse]

Possible damage from power valve screw coming loose and falling into engine

read here
threadlocker-on-power-valve-screws-pics-t304263-30.html

[Mike W.]

Jeez I hope not. I have seen that thread and it seems many of the 3.5 engines suffer from oil consumption problems. Actually a lot of modern cars due to low tension rings. That might make sense, but the rarity of the smoke wouldn't fit the pattern.

[yeldogt]

All of my pathfinders have used oil -- it's the only problem they have

[04pathse]

All of my pathfinders have used oil -- it's the only problem they have

1 qt per 1000 miles sounds excessive even for a Pathfinder

[Mike W.]

I think it used 4.5 qts in 6000 miles. As per the pattern I've seen on other engines in the past, it used less at first and more as time went along. 1400 miles into the change it had only used about a half a quart. But by the end of a 4K vacation it was more than a quart a thou. Just changed it today, we'll see what happens. Many of the miles were hard miles, 75-80 and pushing 100F.

Cylinder damage is a possibility from either power valve or cat breakup, but I sure hope not. As little as I drive it I can put a lot of oil in it before doing rings and bearings. Are Valve guide seals ever a problem on these engines? At 146K it's not a virgin, but not high miles either. As inexpensive as they are I might try a boroscope inspection to see if anything turns up. It might be an issue on the drivers side bank, that post cat O2 sensor has already been replaced and looks black and sooty compared to the pass side one. Nothing I haven't done many times, but I really don't feel like it, especially since I bought a nice low mileage example trying to avoid stuff like this.

[macgiver]

You need to just get a 007 License plate ?? Justify the smoke , and any oil slick trail.

[yeldogt]

Another issue is they tend to leak a little -- the rear main seals and the oil coolers .... may not drip much .. but combined with with engine use .. you have to watch the oil. Last oil change I did the oil cooler seal again and replaced the smaller of the two oil pans (they rust)

I have never seen any smoke and my original one is still with a neighbor at 250k -- we don't drive it much ... my guess is I do have to put 1qt in 1k mines. Car now at 107k.

Do to the development cycle -- the later pathfinders still only had the 4 speed transmission. The engine is spinning at 80mph -- I think this adds to the use as well.

[Mike W.]

Funny you mention the rear main seal, it had started leaking before vacation leaving a nice little puddle after even a brief run, and I mean brief, just moving from the street to the driveway. But I never noticed it on vacation and it's dry beneath it now. Small favors I guess.

Oil cooler? What oil cooler? I haven't been into the truck that thoroughly, but I haven't seen any evidence of one.

[04pathse]

Oil cooler? What oil cooler? I haven't been into the truck that thoroughly, but I haven't seen any evidence of one.

post6765016.html?hilit=oil%20cooler%20leak#p6765016

[Mike W.]

Interesting, I had no idea. A little oil to water cooler I see. I looked thru the parts breakdown on Infiniti parts and still didn't see anything. No problems at the moment but at least I know about it.

[yeldogt]

The oil cooler is an easy fix w/ new "o" ring .... and don't mess with a rusting pan. Replace -- aftermarket is fine (cheap)

Have found I must not use SYN oil --- guess it's too thin when everything cools.

.... DINO high mile Castrol is what I use. Also started using the 10/30 at 100k

[Mike W.]

No leaks except for the rear main that came and went fairly quickly, so the oil cooler isn't an issue, fortunately. With only 16K I've put on it I haven't done that many oil changes. Started with synthetic, then went dino, then the last was synthetic, Liqui Moly 5-40 which dramatically cut consumption on my BMW 525it. Actually on this most recent change it didn't start really going thru it until I threw in some store brand dino 5-30, but I think it was more being 4500 miles into the oil change than the oil itself.

Still the smokescreen has only happened twice, otherwise nothing out the tailpipe that I can tell.