Postby smj999smj » Tue Dec 24, 2019 4:46 am
I never heard of "road noise" as an engine description, but Nissan engines don't run like like "sewing machines" as many Honda engines are described. That said, there have been some instances of bad fan clutches that will cause a constant "roar" from the engine compartment. Another noise that sometime occurs is a "whining" noise that can occur if the upper timing chains are cutting into the plastic tensioner faces, which doesn't happen to all but does happen to some.
Vibration is a common complaint at idle on these engines, which seems to be nature of the beast. If a scan tool or tuner is used to bump up the base idle, it does improve this. Vibration at highway speeds can occur with a failing driveshaft U-joint. There have also been a number of 05-10 Pathfinders that have or have had trans cooler failures inside the radiator which cause cross-contamination of engine coolant and transmission fluid. Signs of this can include white streaks in the trans fluid, strawberry custard-like goop in the trans fluid or oil in the coolant reservoir. Signs of previous repair can include a replacement radiator (although many have been replaced to prevent this problem and not necessarily as a repair) or evidence on a vehicle's history report, such as on a Nissan dealer's history or a CARFAX report.