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2003 blowing blue smoke


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Hi guys, this time it's my dad's rig that's acting up. 2003 SE 4x4, about 82k on the clock. A few weeks ago, after driving it 40 miles or so over a mountain pass, parking it for maybe a half hour, and restarting it, he noticed it was blowing blue smoke everywhere. This combined with the oil consumption (about a quart and a half per 3000 miles) made him think the PCV was bad, so he had it replaced. The issue went away and the truck seemed to run better with more power. The exhaust sounds different (my dad says it sounds 'wet'). The oil consumption did not change.

 

Today, again after crossing the mountain pass, sitting for a bit, and restarting, it blew smoke again. Dad says it feels down on power like it was before. Exhaust sound hasn't changed. No CEL or codes. It doesn't smoke on cold starts or during normal driving, and he restarted it multiple times throughout the day with no smoke cloud.

 

I've heard the PCVs on these are garbage but I can't imagine it would've lunched that quickly. We haven't checked the power valve screws yet, but a recent compression test showed even compression on all cylinders. Mileage is normal. Any ideas on what could be causing this?

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Yeah, black smoke = running too rich. Blue smoke = burning oil

 

 

Worn rings or a bad valve would have been diagnosed by poor compression on one or more cylinders. If all cylinders are testing with good compression, and the problem is most noticeable at startup, but not as noticeable while driving, the valve stem seals could be worn.

 

Read more here

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Who replaced the PCV valve? Was an OEM part used? Were the upper and lower intake manifold gaskets replaced, as well as the throttle body's? Any engine codes present? Ideally, thread locker should have been put on the power valve screws while everything was apart too.

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I have seen this kind of behavior with toasted oil rings and good cats. Solid compression, no smoke except after a hot start and only for a few seconds. Heavy oil use with no apparent cause.

 

Check your tail pipe for soot, fairly heavy deposits will be there if you have this type of issue. Given you engine type and my understanding the power valve screws could give you the same results.

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A local garage did the job and they somehow managed without removing the intake. Apparently the guy thought he could just reach in underneath and do it quickly... when my dad picked it up a few hours later the guy had bandaids all over his hands LOL but I guess he managed to get it in. I don't know if the part was OEM or what it was. Since he didn't disturb the intake the gaskets are all original and the power valves have not been checked.

 

What's getting me is that these issues seem like something you'd see in a much older engine... which points either to abuse by the PO or ingestion of valve screws. Time to check the screws I guess.

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I find it impossible to believe that the PCV can be replaced without removal of the upper and lower intake manifolds. Are his hands snakes? I bet they used a Fram PCV or something. How could he have unclipped the PCV hose without any tools?

 

I think you should pull the UIM and LIM, apply red thread locker on the power valve screws, and replace the PCV valve and the gaskets where required. Do you want parts numbers for everything? Provide your VIN if you do.

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  • 3 months later...

Alright, so, three months later, and the engine's burning roughly one quart of oil per 1000 miles (which the dealer tried to tell him is normal). I know he should take apart the top end and fix it, but he's reluctant to get into it. I'm trying to convince him to compression test it, just to rule that out. Anyway, it hadn't been torn into since Slenderman put the PCV in. It kept right on running and driving as it should, except of course for the oil consumption, until my dad tried to take it over a pass yesterday (a pass he drives it over a few days a week) and it started surging.

 

It didn't throw any codes, but the engine bucked and surged on throttle, whether it was in drive or not. He could rev it up a little if he feathered it, but it went right back to surging when load was applied. It idled fine. My dad limped it home and took it to a mechanic who found that a vacuum line was clogged with carbon. He apparently had to ram the crud out of the hose with a piece of wire. He put a new air filter in it too. We drove it home without issue.

 

I was curious, so I looked under the hood after we got the truck back. The only line without dirt on it (and thus the line I assume was clogged) is the one between what the FSM tells me are the "swirl control valve control vacuum check switch" and the "swirl control valve control solenoid valve." (And I thought my WD's EGR-BPT valve was confusing.)

 

I'm a little confused as to how carbon, or anything for that matter, would get into that line, since it dead-ends at a sensor (erroneous signal from which likely caused the surging) and any leaks would (I assume) pull ambient air into the tube rather than pushing crud from the engine into it. No doubt the engine's been spitting out some excess carbon from all that 5W30 it's been guzzling, but how on earth would it get into a vacuum line? :wtf:

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The bugger did it again today after a car wash. The engine gets up to around 2k just fine, in gear or not, and then suddenly loses power, finds it, loses it, finds it again. It doesn't feel like the engine's struggling, it feels like the throttle's slamming shut. Once or twice, revving in neutral, it hiccuped at 5k. It'll go on like it's got epilepsy and then suddenly it clears and it's fine. Then it spazzes out again. We pulled the vac line from before, and it was clear. We tried the line underneath it and found some kind of white flakes (looked like sea salt) inside, but it wasn't clogged. It still bucked and surged (hard enough to rattle the trailer hitch), even with the lines unplugged. Still no CEL.

 

Video of the problem

 

Here's the sea salt looking stuff:

IMG_1468_zps96fec46c.jpg

 

I'm looking at the idle and accelerator position relearn procedures now, and I'll try them first. The problem didn't start with a dead battery so I can't imagine that's the problem but at this point it's an easy thing to rule out. I'm also looking up testing procedures for the electronic gas pedal (because some numbnuts thought an electronic throttle was a good idea) and the throttle actuator. Seems like if a sensor was reading weird enough to make the computer slam the throttle (thinks it's engine braking maybe?) it would trigger a CEL, but that may be asking too much of a computer system clearly designed by gibbons.

 

We took it down to the gas station before filming it and met a guy with a flogged-to-hell 2WD 4-cyl Hardbody. He said it had 800k on the clock. It ran a little rough and used a little oil... but it was doing a whole lot better than this bugger.

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Dad found another reset/relearn sort of thing on Nico. Here's the screenshot...

ScreenShot2013-08-04at90757PM_zpse6b4e6e

 

Now it's running like nothing ever happened. We have no idea what made it need this, or why this fixed it, but it accelerates like normal again. :shrug:

 

The more I mess with this rig, the more I like my WD.

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  • 2 weeks later...

^Missed that last reply, didn't think to try it. The mechanic swapped out a swirl valve solenoid and the engine hasn't acted up since. Still slurping oil of course but the throttle does what it's supposed to.

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I downloaded the manual. We know the CEL is functional because it came on when Dad tried disconnecting the MAF, and again when we reset the computer (blinking to indicate resetting or whatever). We don't have an OBDII scanner but we've taken it in a few times and been told it doesn't show any codes (other than the code from Dad pulling the MAF plug).

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If you have a smart phone with bluetooth. Check out the Torque App. Works with bluetooth OBDII adapters. The app costs $5 and the adapter costs about $20-35 on Amazon.

Its what I use and works very well.

App: https://play.google.com/store/apps/details?id=org.prowl.torque&hl=en

Adapter: http://www.amazon.com/BAFX-Products-PIC18F2480-diagnostics-compatible/dp/B005NLQAHS/ref=sr_1_1?ie=UTF8&qid=1377009766&sr=8-1&keywords=bluetooth+obd2

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  • 4 months later...

One of my cousins uses Torque and he seems pretty impressed with it. If I ever replace my flip phone I'll have to check it out.

 

The consumption's getting worse. About 1100 miles after an oil change, it came in more than two quarts low. :ohno01: Dad's priced a new engine (more than he wants to spend on this thing), and a rebuild would cost more due to the shop time involved in getting into the heads. I'd love to have a go at it but it's way beyond my skill level.

 

The crazy thing is, it still has plenty of power and drives fine. :scratchhead:

 

My research suggests that the later 3.5s (05-06) didn't have this problem. Does anyone know if these mate to the R50 Pathfinder trans?

 

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Sounds like you need to pull the intake yourself and check those power valve screws. If the were loose, the original guy should of checked for damage to the intake itself. Kind sounds like damage to the cat converter to me. Being when you perform the reset and everything works fine for a few, something is telling the computer to do something it's not supposed to. No codes tells me something mechanically failed. You could pull the plugs and do a compression check to see of the rings are worn(May also need a leak down test). If they were low, you could put a small amount of ATF down the cylinders to help reseat the rings. Me? I'd pull the intak and check the screws myself, then pull the cats and inspect them to see if the are coming apart.

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The throttle flapping's long since solved, it just needed a new swirl control solenoid valve solenoid something or another. Are you suggesting the cats in relation to that or to the oil consumption? I've read about Maximas with the smaller VQ sucking bits of catalyst into the cylinders (some kind of passive EGR via the exhaust valve timing) and destroying the bores/rings, but I've never seen it mentioned in relation to Pathfinders. Doesn't mean it's not possible though.

 

We haven't checked the compression or valve screws on it, mostly because it looks like we'd have to remove an awful lot of stuff just to get to them, and it's Dad's daily driver so it can't be torn apart for long. However, the possibility of the rings sticking is interesting (and not unlikely of the PCV's been dumping oil into the intake). I found a post on a VW forum from a guy who said that filling his cylinders with carb cleaner, letting it sit a while, and then pumping it (out along with gobs of carbon) fully stopped his oil consumption. We'll have to look into that... it would be nice if the problem's that easy to solve.

 

In case it isn't, any pointers about how to find a good replacement?

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As far as the converters, what happens is that they begin to crumble, or a screw makes it through the cylinder and embeds itself into the cat, and it no longer works properly. In doing this, the o2 sensors read incorrectly. They tend to fatten up the mixture and wash the cylinders, loosing compression. Usually the giveaway is that the oil smells like fuel. Yes, I've have done hundreds of Altima and sentra motors for this same problem. I have also replaced several cats on G35's who collapsed and created the same issue( replacing the cats usually fixed it). On those, the PVC system is built into the valve cover gaskets and they would stick open and suck the oil down. Replaced the valves over gaskets, spark plugs and performed a induction service and got them to reseal the rings and stop oil consumption. I know it sucks, but ya gotta take some things apart and inspect.

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You don't have to remove too much crap to at least examine the power valve screws, just the upper intake manifold. If you are flexible enough maybe you can even apply threadlocker to all of them without removing the LIM; I knelt on the radiator core support to do so but I'm a small person.

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