Looking for advice-94 Nissan Pathfinder V6 noise

[jejm1975]

I have a 1994 Nissan Pathfinder SE, V6, manual transmission with 164K plus miles. She doesn't use oil, but she has developed a bit of noise under the hood. I am thinking that it may be some sticking lifters or pistons and I would like to know what type of oil or additive that I could use to clean her out. I have already ran some Gumout ® Regane ® in the fuel system. I was thinking of using some MMO for the lat 1K miles before the next OCI. So is there anyone will to offer some suggestions with some data that I can research to back it up. I do have reservations on using any type of strong solvent, because I do not want to risk damaging her motor. Thanks in advance for anyone willing to contribute.

 

[Merkava_4]

Maybe it's time for a valve lash adjustment.

 

[spasm3]

If you are not sure what the noise is, i would find a good independent mechanic. You don't want to be trying additives and different weights oils etc, if your problem is a serpentine belt idler or a worn water pump.

 

[lugNutz]

Originally Posted By: spasm3

If you are not sure what the noise is, i would find a good independent mechanic.

This!

 

[Revving2Redline]

Have a garage look and listen before adding liquid fixes. It could be age too. If a additive is recommended find the problem and use a quality product from LiquiMoly or other high quality carrier.

 

[Triton_330]

MMO is a fine product. I'm not saying anything against the others, just saying that what you intended to do sounds just fine. Like others have said, have a mechanic listen to it beforehand if you want.

 

[901Memphis]

Try some liqui moly Mos 2 http://www.amazon.com/gp/aw/d/B003U4O414?pc_redir=1405053418&robot_redir=1

 

[wrcsixeight]

Probably the exhaust manifold peeling off the head and ticking. That vintage Nissan V6 loved to do that, over and over again. Usually louder when cold though. I'd investigate that, and anything else, before any throwing any more tune up in a can at it.

 

[Zaedock]

Internet troubleshooting seldom helps with such a vague description. "Noise under the hood" could mean 100's of different things. As a mechanic, I recommend taking it in and having it looked at before you start throwing fixes at the engine without truly knowing the problem.

 

[artificialist]

You can buy an automotive stethoscope for very little, and probe the engine in various locations to find a noise. I do recommend using a good gasoline additive regularly, but I never recommend using any engine oil additives in an engine that still functions well.

 

[jejm1975]

My apologies, I forgot to mention that I recently changed the timing belt , radiator (damaged it while changing the timing belt), spark plugs, rotor, rotor button, fan belt, alternator belt, alternator, power steering belt, started, timing belt tensioner idler, fuel filter, oil filter, air filter, water pump and I think that is about it. Also she did sit up for about 36 months while I was incarcerated, with the monthly occasions where my dad would crank her up and let her idle for fifteen minutes or so. The noise could be in the catalytic converter, but I am pretty darn sure that it is the lifters since the noise frequency increases when I depress the accelerator. Indeed the noise quietens after she warms up, and even appears to subside at times, until she cold starts, then the cycle starts all over. I confess that I am not a certified or salty mechanic, but I do all my own work except the internals of an automatic tranny, and that is mostly due to not having adequate work area to do it correctly, hence my reasoning behind sticking with manual trannys now. And thank you to everyone for your contributions.

 

[Greasymechtech]

Change the oil and filter and add a pint of marvel or rislone for a 3k cleaning interval. Pull a valve cover off for sludge inspection. Check oil pressure. Stethoscope time.

 

[jejm1975]

Thanks for the assistance. I'll try that at the next OCI which will be soon.

 

[spasm3]

I have had new aftermarket tensioners make a heck of a racket. Also an exhaust manifold bolt thats broken can make noise too.

 

[jejm1975]

I think the noise is actually coming from the exhaust and there is something weird going on with the ignition system that is causing some internal backfiring. Oh, I did change the oil. I used a MicroGuard filter from O'Reilly's and Castrol GTX High Mileage 5W-30 plus one qt of MMO. NOT GOOD!!!!! Poor Pathfinder started leaking oil at the oil filter! NEVER again. I had to put the old Fram TG back on and added some straight 40 plus more of the 5W-30. Will have to change oil again, now that I have a new Fram TG3682 and some Castrol GTX high mileage 10W-40. Almost cost me my engine!

 

[Zaedock]

Your leak was either a defective filter or incorrect installation. It has absolutely nothing to do with running 5W30.

 

[aquariuscsm]

If you`re using a synth oil,try a good dino like GTX or PYB 10W30 w/OEM Nissan oil filter.

 

[Triton_330]

Originally Posted By: jejm1975

Oh, I did change the oil. I used a MicroGuard filter from O'Reilly's and Castrol GTX High Mileage 5W-30 plus one qt of MMO. NOT GOOD!!!!! Poor Pathfinder started leaking oil at the oil filter! NEVER again. I had to put the old Fram TG back on and added some straight 40 plus more of the 5W-30. Will have to change oil again, now that I have a new Fram TG3682 and some Castrol GTX high mileage 10W-40. Almost cost me my engine!

Hmmm... that's odd. I thought the microguards were currently made by wix/napa? Are you sure you got the correct filter?

 

[jejm1975]

No more leaks after I put the old Fram TG3682 back on. She's holding steady. Is it possible that the MMO loosened up enough gunk to clog up that MicroGuard filter and the oil had no way to cycle so it blew past the gasket?

Originally Posted By: Zaedock

Your leak was either a defective filter or incorrect installation. It has absolutely nothing to do with running 5W30.

As far as incorrectly installing the oil filter, I don't know what type of filters you use, but there isn't a wrong way to install mine. I lubed the seal with oil, lined it up and screwed it on and tightened it down... not much to mess up there. Been changing my own oil for twenty-two plus years now. The filter and the gasket look fine, although I did save the filter and mat, if I get bored, dissect it to see what's going on in there, as it does feel awfully heavy for a drained filter.

 

[jejm1975]

Originally Posted By: Triton_330

Hmmm... that's odd. I thought the microguards were currently made by wix/napa? Are you sure you got the correct filter?

I used the one that the O'Reilly employee looked up and said was the correct one.