So looking for some feedback, wondering if anyone else has encountered this issue. Car is the 02 GTP coupe.
Cold start, engine fires right up and idles great. Quiet as a mouse. Accelerating away from the curb at minimal throttle, you get to about 2k RPMs with a light load on the engine, and I get a noise that sounds like a bunch of rocks being shook up in a plastic tupperware container. If you put your foot in it to get over 3k RPMs and increase the load on the engine, the noise goes away completely. As you decelerate and the engine passes back through that 2k RPM band, you again get the noise that sounds like rocks being shook up in a tupperware container. Once back at idle the noise is gone.
Definitely not a knock, but has more rattle to it than straight up lifter tick. Sounds like the piston slap I get on my 8.1L, but the 3.8 is not known for piston slap.
After driving about 2-3 mins, the noise disappears completely and the engine is smooth and quiet at all RPMs.
Cannot duplicate the noise in the driveway just by revving the engine, it has to be under part load while driving.
No noise at all on a hot start, once warmed up even a little there is no noise.
I've been doing a bunch of reading on this, and suspects include:
- Worn Harmonic Balancer
- Lifter noise caused by oil drainback over night
- Worn Supercharger coupler
- Incorrectly installed flex plate cover
Right now running Mobil 1 5W30, about 4k miles on the oil, and I forget what kind of filter, probably a Napa Gold.
Anybody have anything similar?
