Towncivilian

Instead of putting harsh solvents or hydraulic fluids in your crankcase, I'd try running a few short oil changes (3k to 3.75k miles) with a conventional motor oil high in detergency such as Pennzoil Yellow Bottle 5W-30 and any decent filter first. Look through the oil filler hole, do you see any significant nastiness or buildup? How long of trips do you usually take (time & miles)? If the trips are very short, the oil may not have a chance to reach operating temperature to boil off excess moisture, and since the engine is cold it will be running rich and allowing more fuel dilution of the oil.

I believe all R50s in whatever year range the recall applies to are eligible for the fuel filler tube recall. My PF has always been down south and its fuel filler tube was replaced under the recall.

Bosch filters are manufactured by Purolator. Bosch Premium are clones of Purolator PureONEs; Bosch DistancePlus filters are different filters completely. The lower end Frams are horrible value for the money. The ExtraGuards have nitrile combination anti drain-back valves and bypass valves (the nitrile can harden and become brittle over time/heat exposure, and the idea of a single nitrile chunk serving two purposes isn't appealing IMO), fiber end caps holding the filtering media together (which likely isn't ideal for a long oil change interval), and a pathetic amount of filtering media compared to similarly priced filters. Fram ToughGuards have silicone anti-drainback valves and more media, but still have fiber end caps. The Fram ExtendedGuards (recently renamed to "Ultra") are built like tanks and have a synthetic blend media, silicone ADBVs, and very thick cans; I wouldn't hesitate to run one. I would much rather purchase and use a Purolator/Bosch, Wix/NAPA Gold, or OEM filter for a similar price of a lower-tier Fram filter. Here are some informative diagrams: This is a Fram ExtraGuard filter cut open: http://i18.photobucket.com/albums/b150/bigdaddyII/Oil%20Filters/IMG-20111004-00215.jpg This is a Purolator PureONE PL14610 I cut open: http://i198.photobucket.com/albums/aa36/Towncivilian/oilfilter1/DSC09330.jpg http://i198.photobucket.com/albums/aa36/Towncivilian/oilfilter1/DSC09332.jpg (sorry for the lousy links, this new forum software seems to hate my BBCode)

There might be bits of charcoal remaining that are causing your P1444 code (and possibly P1447). P0325 (knock sensor) is likely a side effect. You can try adding a small in-line fuel filter to catch any charcoal - see this thread on NICO: http://forums.nicoclub.com/p1444-code-and-poor-man-fix-t441648.html

Faulty engine coolant temperature sensor? Measure its resistance (see page EC-157: http://www.nicoclub.com/FSM/pathfinder/1998_Pathfinder/ec.pdf ) and replace it if it's bad.

If it clears, it should do so within a few driving cycles. The cap is probably around $20 to $25.

P0325 is most likely unrelated and will go away when you solve the P1440 code. Tighten your gas cap; if it doesn't disappear within a few driving cycles, replace your gas cap with a new OEM one.

All the brown crud. I've never seen that before when wiping the transmission dipstick. I don't know if the dipstick is magnetized. Although that gray/greenish spot is suspect as well, now that you point it out. The fluid wiped on the paper towel is difficult to see; it's very clear red.

I checked my transmission fluid level today and as I wiped the dipstick on a paper towel a few times, this crap appeared: http://dl.dropbox.co...12/DSC09395.JPG Transmission details: 2001.5 Pathfinder, 131.8k miles RE4R01A-HD B&M 70268 transmission cooler (19k GVW IIRC) plumbed in-line with the stock cooler Magnefine in-line transmission filter, in use for around 13k miles Castrol Import Multi Vehicle ATF + 1 10oz. bottle of Lubegard Red Fluid was completely exchanged with Castrol Import Multi Vehicle on 10/31/2011 and a pan drop & filter change was done at the beginning of that year. The debris on the paper towel almost looks like it's from the sides of the transmission dipstick itself, based on the way it left debris on the towel. Why would there be a significant quantity of debris on the dipstick? The fluid is recent and still looks & smells fine, and the Magnefine should catch nearly all ferrous particles even if it were in bypass and much of the non-ferrous stuff assuming the filtering media isn't clogged or in bypass. Shifting feels fine, fluid level is spot on. Ideas?

Replacement OEM headliner is in the vicinity of $265 at Courtesy Parts. I don't know anything else about headliners, sorry. Unclog your sunroof's drain tubes to prevent further water damage. See BT-36 for a diagram: http://www.nicoclub....thfinder/bt.pdf

Try bleeding your clutch with some DOT4 brake fluid, it might help your cold weather performance. Brake fluid is hygroscopic, so the fluid probably contains some water especially if it's not been changed in a few years.

http://www.nicoclub.com/FSM/pathfinder/1997_Pathfinder/ To save a copy of the FSM, right click -> Save As on every PDF, save them into a single folder, then use fwd.pdf to navigate. It's gettin hotter down here, unfortunately.

P0136 is a rear oxygen sensor code and can be ignored indefinitely unless you have emissions inspection in your state. If there is an Advance Auto Parts near you, you can get a direct fit Bosch O2 sensor for $65 before tax if you order online using discount code VISA. http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product__18730020-P_291_R%7CGRPEMISAMS____ For P0335, see page EC-201 in the factory service manual for a diagnostic procedure: http://www.nicoclub.com/FSM/pathfinder/1997_Pathfinder/ec.pdf For P0500, see page EC-251.

Here's another interesting, in-depth oil filter study: http://www.gmtruckcentral.com/articles/oilfilterstudy.html

I'd use something like Amsoil Power Foam or Mopar Combustion Chamber Cleaner rather than Seafoam to clean the intake manifold.

With garbage $2 STP "injector cleaner" or what-have-you, yeah you're probably right that it ain't gonna do jack since all they contain is crap like kerosense and other solvents. PEA (poly-ether amine) based cleaners such as Chevron Techron, Redline SI-1, or Gumout Regane clean effectively without leaving behind their own deposits and are recommended by several OEMs (Chevron and BMW co-developed Techron which was the first product to contain PEA) for effective fuel system cleaning.

My R50's original O2 sensors are Bosch supplied, for what it's worth.

And you should check for water entry in the differentials/t-case if you haven't yet. What fuel additive did you use?

They have lousy construction for what you pay for them. Fiber end caps, relatively low amount of filtering media, combination nitrile anti-drainback valve and bypass valve... no way in hell I'm paying $5something for one of those. I wouldn't be opposed to running one if I got it for free, but it definitely isn't my first choice. A Purolator Classic for $3.27 at Wal-Mart is a better choice. The only Fram I'd run is an XtendedGuard which is built like a tank.

Go for it, I use Castrol IMV in my PF and I'm pleased with the shifting quality.

What grade M1? By "cheap NAPA filters" are you referring to the Pro-Selects? Those are made by Wix and are well built for the price; you can certainly do much worse (Fram ExtraGuard or e-core filters, which use a nylon cage instead of a steel center tube). I find it a little odd to pair a high-end oil like Mobil 1 with cheaper filters, but there's obviously no problem in doing so as evidenced by your engine's condition. A 4k change interval is a little low IMO for a top-tier synthetic, but I believe our VQ35s are fairly hard on oil and it can shear out of grade fairly quickly. I'm running Mobil 1 0W-40 & an M1 EP-110 filter right now out to 7,500 miles and will get a used oil analysis done to evaluate the condition of the oil. If it's all good, I'll probably continue running M1 or pretty much any other synthetic oil at 7.5k change intervals. Are you talking about the turbine revolution sensor? Looks like that's on top of the trans case

Wow, 250k is indeed a milestone. You're definitely doing things right. What oil & filter do you use and what's the change interval, out of curiosity? Is any oil consumed? Hope the poly bushings serve you well.

Got 18.6 MPG my last tank.

See this thread on NICO about P1444 (which is the same as your P1445): http://forums.nicoclub.com/p1444-code-and-poor-man-fix-t441648.html Although the OP had visible charcoal and you don't seem to, you might want to place a similar filter in-line after you fix the problem which may help prevent another valve from kicking the bucket. Just a thought.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2571353