I have a loud tapping noise on start up that goes away when warmed up. With a scope it sounds like it is either coming from the timing cover or fuel rail, but I am thinking it is more than likely a lifter. I am getting ready to do a motor flush to see if that clears my problem, but has anyone else experienced this problem and what did you find???? My Quest has only 80,000 on it and I feel that is very low mileage for a Nissan.
Loud tapping from the top end of the motor.
on 2007 Nissan Quest
Also sounds to me like lifter problem. After you do flush may want to up your oil weight to 10w-30 if not already. May want to also add some Lucas oil treatment too- if so though i've found synthetic one works much better but like $17 a quart at autoparts store.
Thanks for the reply. I have used Pennzoil full synthetic 5w30 and a K&N oil filter. I will try to use 10w30 if the flush does not work. I also added the Lucas motor treatment with my last oil change. Still tapping. Hopefully the flush does the job!