Chriskaw440

according to my 1990 SE pathfinder, the round "disk" on the dash top is a temperature control sensor.

Yank out all of that STOCK AIR FILTER box and junk and put a cone type (K&N) air filter on it. Made a NICE improvement on my 1990 SE 4x4....much more peppy now that the engine could actually BREATHE. Gas mileage improved a little bit too. Did mine years ago and still going strong. I have pictures if you would like to see. Its a piece of cake.

Thanks for the tips. For now I just removed the belt and drive it as little as possible until after the holidays. At least driving it to the gym now I get a pretty decent upper body workout with no power steering LOL.

my 1990 with 250,000+ miles on it ticks too from cold start to sometimes at normal operating temp....added Lucas oil treatment after flushing with seafoam and its getting a bit quieter finally....(was really loud after the flush job). I'm just planning on replacing the hydraulic lifters soon since it's not a difficult job. Engine still kicks ass so no plans to replace the entire engine.

Howdy all, Well my 1990 sprung a tiny leak in the power steering high pressure line, right up next to where the fuel filter sits next to it. I've never replaced anything power steering related (mechanic replaced the pump a few years back) and was just wondering if there was anything out of the ordinary I need to look out for when replacing it. I have found the assembly for about $55 to $60 bucks at Rock Auto. Looks pretty straight forward but just thought it couldn't hurt to ask. thanks! -Chris

Mine usually sits same place as ac92's post photo shows above and I drive a 1990 SE. Never goes any higher and I have great heat in the winter time. Only time mine ever went past the halfway mark was when I was hauling ass to to the beach here in SC and it was about 99 deg outside....I was doing about 85 mph. I have to check my temp sensor connection every now and then though because a few years ago it started running really rich and was blowing black smoke out the tailpipe and my mechanic fiddled with the electrical connection/plug on the sensor and found it to be loose, he got it to fit better and problem was solved. With age of my ride, the plastic on the connector is pretty brittle so the clip doesnt always hold it on in place very tightly. I doubt I could ever find a new connector so Im considering just cutting it off and splicing the wire and just solder it to the sensor permanently. But yeah, typically my temp gauge is always around 1/4 of the way up or slightly less in cold weather.

Thanks for the tips, yeah I was thinking about running a second flush through this weekend but now like you guys suggested....just let it idle for a few instead of driving it (like the seafoam directions say to do). Im not expecting miracles with 250,000+ miles but just a wee bit quieter (like it was) would be nice I'm tired now though so maybe after a good long nap.....

seafoam 'claims' it liquifies any gunk/carbon build up...but I do find that kind of hard to believe. I'm still banking on the possibility that the flushing just cleared out a lot of the build up (which was probably muffling a bit of engine noise) and now that its cleaner, its noisier as its revealing sounds of worn lifters....which after 250,000 + miles, I'm not all that surprised.

Thanks Beast....yeah I'm thinking it's time to replace them too. Doesn't look hard at all now that I have researched it in my repair manuals....at least for the passenger side of course since the plenum doesn't have to be removed. In the meantime all I can do is just keep some good oil in there and let it warm up a bit (especially now that its getting colder outside). Once its fully warmed up, the tapping is practically non existant. The passenger side set on mine is also the noisy side. I may just do one side for now, and the drivers side later on since it would be a tad expensive for me to purchase twelve new lifters at once.

I didnt want to go thinner and thought I would try syn to see if it made any noise difference. Just checked inside the valve covers while engine running....oil flows very well so the pump is not an issue. when I used 10w 30 in the past, it was noisier and others have said with high mileaage, go a little heavier for extra protection.

thanks. I've done the knock sensor job all by myself about 2 years ago and that wasn't too bad of a project, also replacing all the gaskets along the way. I may just dive into getting new lifters since I also want to replace the idle air control valve that keeps acting up (but the location of it is a pain...under the plenum....) I'm pretty sure the oil system is fine but going to do some more 'testing' soon. I did exactly that when I did the knock sensor...took photos of where every thing goes first, and labled connections and wires.

....85/90 gear oil should do the trick! ha! I don't know of anything between 10w/40 and 20w/50...... I've heard good things about Lucas heavy duty oil stabilizer and figured it was time to start using it. Definitly nothing thinner oil-wise. Love the engine, still strong as hell and will spin the tires even in 4x4. Just hate the friggin noise now.

thanks, not the manifold though. Been through the exhaust manifold replacements aready, it's definitly lifter ticking/tapping sounds. It always had a couple seconds of it at cold start up....then dissipated once the oil circulated fully. Now it last a lot longer and actually happens in "waves", like...gradual light tapping to louder tapping...then stops....then starts over again...then stops....etc etc..

10w40 synthetic Mobil 1 and Lucas additive.

My 1990 has 250,000+ miles on the original motor, finally made the took the initiative to flush the engine with Seafoam and followed instructions to the T, now the lifters sound like a metal can full of ball bearings banging away, even after fresh 10w40 synthetic Mobil 1 and Lucas additive. Engine still runs like a scalded dog like it always did, but damn it taps 10 times worse than it ever did....and for a lot longer. I should have skipped on the seafoam sh*t. what little sludge it may have had in the engine sure made it run quieter.....and it never did or does burn any oil. Any suggestions for quieting this thing down? Thanks to the design of the engine, probably best to just get new or rebuilt heads and such. (ps... I just did the oil system flush. Added the right amount of seafoam to the oil, drove it 35 to 50 miles like instructed, drained and added new oil.)

I want headers I had them on all of my RX-7's. always a sweet improvement. then i got married and bought a house and 3 dogs......etc etc. I wish Santa would bring me some headers for my '90 pathfinder. I hope to get under the hood this weekend to look for broken bolts or rattling heat sheilds.

thats one of my next 'inspections' to do....the passenger side manifold & bolts. The drivers side was already replaced a while back.

well when I said I could do it myself I more or less meant, with the help of my buddy up the road, and soforth.....and taking the time to do it for my first time ever. I also just figured they cost more than they apparantly do I don't think they are bad enough to warrant a tear down anyway since it runs so great and still gets great gas mileage and doesnt burn any oil. Just age is all with 246,000+ original miles. I've been considering changing to synthetic as I have used it before in my other vehicles with great results (although they were rotary RX-7's.....) Last I remember you can switch back to dyno oils...but its not the greatest thing in the world to keep changing brands and types everytime you change your oil due to the different chemistry make-ups and additives that different manufacturers put in their blends. Just find the brand you like and stick to it for the most part. Im certainly not going to fall for the junk like "Motor-Up" or "Dura-Lube" or "Slick-50" as those are all proven to be junk or just mineral oil with some coloring added.

Howdy all, Just a little question regarding the noisy lifters that go along with high mileage for these V-6's......I've noticed that mine are getting more noisy eventhough she runs perfectly and mileage is still awesome etc etc...no smoke and still great power. I don't think its any mainfold leaks since its noisey/rattley even after full warm up. I'm also going to check for loose exhaust stuff banging around. I was wondering if there are any recommended (or NOT recommended) lubricants/additives out there that anyone has had decent results with for just such a thing. I can't afford a valve job or new lifters/heads eventhough it would be nice and I could do it all myself.... I know some additives are just junk/snake oil stuff.....but I just thought I would ask around. I do use castrol 10w-40 oil and change every 3,000 miles. maybe go to a heavier weight? thanks. -chris

yeah thats a lot of miles ....but not quite a million and then some you will probably die of natural causes before the wonderful pathfinder breaks the million mile barrier. then again, only about 808,000.00 + miles to go!!! Hope you use darn good oil in it! long live the pathfinders!!!!!!

I just shove a few sticks of butter into the oil fill hole.

well on older ones like my 1990, that "snakeing" or unstable rear end was caused by the rear control arm bushings being shot or ruptured, allowing movement of the rear axle back and forth, mostly when a load is applied (getting on and off the gas.....). I replaced my bushings and been perfect ever since.....as has been the case with many others here.

Yeah those two highlighted in green look about right....they connect to the inlet and outlet heater hose lines for the most part I do believe. Hey I see the EGR hose on there shown at the bottom right ....(thought it goes to the PCV also....I could be wrong) and I couldnt replace mine at the time and I could use that one also if you have it. I think I will take a digital cam shot of my plenum and point out the premolded hoses I have trouble finding. thanks for the help! -Chris

The two small diameter (about the same as fuel line hose) coolant hoses that attach at the rear underside of the plenum (there are coolant lines on the bottom of the plenum....) Originally they are pre-molded at about 90 deg angles....so replacing them with standard straight hose that you have to bend so much usually results in a kink...and I couldnt find any of those anti-kink 'springs' or whatever they are called for hose that small....but I did manage to make them fit eventually without a bad kink. Yeah engineers need to pay more attention to ENGINE COMPARTMENT ACCESS ROOM to the commonly replaced parts instead of how fancy the stupid cup holders are on the interior or an extra two inches of leg room. Todays new cars have vast amounts of space on the inside (oh whoopie do unless you weigh 400 lbs or have a Brady Bunch sized family) and removed ANY access space under the hood so even the Nissan mechanics probably say to themselves "Oh sh*t, here comes another Murano for a friggin tune up....damn." thats just plain incredibly STUPID to have to lower or raise the entire engine just to get to ONE or a couple of the spark plugs. I know this is the case on other vehicles too but you would think that for it to be that much work just to change a spark plug....engineers would realize that "hey...this is stupid....there must be a better way around this"....I mean come on, they are ENGINEERS afterall....supposedly about the smartest people on the planet! If I was buying a new car and asked "can I change the spark plugs and oil filter myself? and they said "no, that requires our specialist/technicians...you'll have to make an appointment and plan to leave the vehicle with us for a few days because we have to actually partially remove the engine for the most part" I'd say fine, show me a car/truck/whatever that is NOT like that please. This is why I like older vehicles better! Besides, by the time they perfect an alternative energy vehicles and make the gas powered reciprocating engine obsolete....I'll be dead of old age anyway.

well my 1990 has 246,000+ miles and especially during warm up / the first few miles, the valves are kinda noisey and I am told its pretty typical, and my engine is the original, never rebuilt. The valves are hydraulic so with this kind of age, they can bleed down faster and once the oil fully circulates and engine is at normal operating temp...it runs considerably quieter. the noise doesnt effect the performance .... it still runs perfectly and doesnt smoke or consume oil. It's just a bit annoying to hear. -Chris