I have a 99 Nissan Maxima with about 130k miles. I am having an
interesting engine problem. A few days ago, a few blocks from my home
at a stop sign, the engine sort of shook up and down a bit. The car's
front gently moved up/down, I let go of my break a bit, and it went
away. Didn't happen again for the rest of the drive. I didn't know
what it was and almost thought maybe it didn't happen. ;)
This morning, a few blocks from my home, it happened again. I saw the
rpm needle shoot up a bit (maybe it went down a bit before it shoot
up) and the front of the car shook gently up/down again...
What could be the cause of this kind of symptom? The Maxima is known
for its defective coils, and I had all 6 replaced (5 from nissan, 1
different-brand from mechanic) 2 years ago. I also replaced the spark
plugs at the time (6 Nissan OEM platinum plugs), at about 115k. Could
the non-Nissan coil acting up causing this problem? Could the spark
plugs causing this issue? The service engine light is not on.
When the coil did went bad last time, the engine was vibrating gently
up/down, but once the sympton happened, it never went away until the
coil was replaced.
Another symptom that may be related to this, and has been happening
for a while, In the morning, when I first start to drive the car.
During the 1st long acceleration on a local street, I noticed the
engine sort of vibrate a tiny bit (at a higher frequency compare to
the idle at stop vib). It's very very subtle, but I feel like there's
a slight lack of power compare to what the car was like before. After
the engine warms up a bit, it doesn't happen anymore. I've learned to
accelerate more gently initially.
I just changed the OIL, Mobile1 10w30. Been using mobile1 since 60k
and the engine's been performing great, until recently...
Any help/pointers will be appreciated. I am not a car person, so
unless it's something trival (like replacing the plugs/coils), I'll
probably have to take this to a mechanic.. but I want to know what
might the cause before I do.