RPMs will fluctuate slightly and cause the lights to dim along with it?

ROHAN BHATT

MEMBER
2014 NISSAN MAXIMA
3.5L
V6
2WD
AUTOMATIC
82,400 MILES

My problems started with a lean code that went away once the MAF was replaced. Also replaced alternator simultaneously. Since then, I've been having this issue with a sort of engine surge where the RPM's will fluctuate slightly and cause the lights to dim along with it. This happens intermittently and occurs when the car is in park or while in drive at a stop. Recently replaced battery, alternator twice (issue persisted with both rebuilt alternators), serpentine belt, ground wiring, MAF sensor, ignition coils, spark plugs, and PCM. There was also oil found in one of the coils, but the surging problem still persists with new ones installed. The valve cover was replaced. No vacuum leaks were found and the charging system checked out fine. Have been chasing this issue for over a year with no luck.

3 Replies

MIKE H R

MECHANIC
3,094 POSTS

Try cleaning the intake with throttle body cleaner, a little dirt or carbon build up can cause the engine RPM to fluctuate. How is the fuel filter? Has it been checked?

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Tuesday, September 13th, 2022 AT 10:52 AM

ROHAN BHATT

MEMBER
2 POSTS

I had it checked/cleaned and still the same. Fuel filter on this car is not serviceable as it is in the tank so I don't believe it can be changed. I do hear a squeal sound as the RPM's go up and down in the rear of the vehicle though. These issues all stop when I rev the engine a bit.