Ok, this just started today. 14 Cruze LT, 91K miles. Fairly recently, new shocks, new struts, suspension links, etc all replaced. So, the noise is this--and honestly, I've been driving for over 40 years, and never heard this one:
On acceleration, or when giving it gas--but not every time--a rhythmic tapping at about 1 beat per second. Not related to engine or vehicle speed (doesn't speed up or slow down with engine or vehicle speed). Sounds kind of like a drummer tapping a wood block. About once per second for 3-10 beats, then it stops and will come back later. I'm wondering maybe fuel pump or an injector getting weird?
Some additional info about this....it seems to be coming and going. It almost sounds like a solenoid is clicking on and off when I'm giving it gas on a hill or speed up. This morning it barely did it at all, this evening, not at all. I hate intermittent problems. Which solenoids might activate when it's getting gas?
Notwithstanding your limitations above, this is my standing click, tick and rattle list:
1. Could be just the injectors
2. Could be the plastic ECOTEC cover rattling
3. Check that the spark plugs are properly torqued -- 18ft-lbs (might as well re-gap them - .028 for a 1.4) and make sure the springs are not stuck/bent etc.
4. Could be a failing EVAP purge solenoid/valve or possibly a vacuum leak causing the purge valve to stay open
5. Could be a lifter tick - try seafoam or valvemedic
6. Could be the timing chain tensioner
7. Could be a sloppy timing chain
8. Could be piston slap/wrist pin failure
9. Pinging caused by low octane fuel
10. Could possibly be an improperly torqued bolt on the flywheel/torque converter (noise from the trans side)
11. Might be a bad wheel bearing
12. Possibly the knock Sensor going off or bad and it can be exacerbated by any of the above.
Thanks. Eventually it will declare itself as something real and significant. It doesn't sound like a classic CV joint failure--but I wonder if that's where it's heading. At this mileage it's not unlikely. I'll try to record it next time I hear it and there isn't a lot of traffic around and post it.