Postby smj999smj » Fri Mar 22, 2013 8:44 pm
If it isn't making noise, I wouldn't bother with the serpentine belt. Belts made with EDPM can last up to 100,000 miles and sometimes more. That said, there were some noise issues with the belt on the early R51's and a TSB issued for it. The "fix" was a different length belt and a new tensioner. I would use the genuine Nissan parts, but if you go aftermarket, it's usually referred to as an "enhanced performance" kit by companies like Gates, Dayco, etc.
My preferance is to replace the radiator rather than the bypass as you can get a good aftermarket radiator for around $100-$160, but I agree the bypass is better than doing nothing at all. Also, keep an ear out for the timing chain "whine" as the upper chain tensioner "feet" have a problem with wearing out. There is also a TSB for this issues with countermeasure chains and tensioner "feet" and there are YouTube videos that demonstrate the timing chain noise.
Also check the front sway bar mount bushings as they tend to wear and spread, causing the bar to contact the crossmember. Countermeasure bushings are available for this concern. Check your engine mounts for splits or leaking hydraulic fluid and check for bad U-joints, both common problems.
Some good upgrades include replacing the rear shocks with Bilstein HD's and installing Airlift 1000 air bags to improve the ride of the vehicle.