Postby smj999smj » Tue Jun 02, 2015 9:30 pm
The timing chain issue is pretty noticeable by the "whining" noise that occurs when it happens. Not all Pathfinders had the issue, but a lot of them did. The reason I heard as to why it happens has to do with the stamping of the chain links. When you got near the end of the life of the stamp, the link edges might not be as clean as when the stamp was new, thus the sharp edges would gradually cut into the plastic "foot" (or, "tensioner face," depending what source you reference) of the tensioner until it contacted the metal tensioner plunger, which is when the "whine" would occur and gradually get louder. It occurs on 05-10 V6 Pathfinders/Xterras/Frontiers. Nissan released a TSB with the updated upper chains and beefier tensioner "foot." Some ways of telling if the job has been done is by checking for RTV sealant other than the color gray at the seam between the front and rear timing covers. If you see black or red RTV, it's a sign that the cover has been off (of course, the repair could have been made with gray RTV, so it's not full-proof method). A CARFAX report could be another way of finding out if it has been done in the past, as well as info on the radiator issue, if that's in it's history.
If you have a Calsonic sticker with a part # ending in -EA215 or -EA265, you have the original radiator that has been prone to cooler failure. No sticker would likely mean it's an aftermarket replacement. If you have the original radiator, I would recommend replacing it with an aftermarket part or doing the bypass method.
The cooler issue is due to a failed seal in the cooler, which starts out slow and gets worse. The contamination will ruin the transmission, especially the solenoids on the valve body. Preventative maintenance by replacing or bypassing the radiator is your best defense.
Some other common problems include bad U-joints, serpentine tensioners, bolts seizing to the bushings in the front and rear control arms, and fuel sending units. If your TPMS sensors are original, plan on replacing the set of them in the not so far off future.