lookin' for ideas... small block chevy with th350... goin' down the road bringing up the rpm's normal driving... when vacuum is high and load on motor is minimized, there is a pretty good rattle... when the motor is under a load bringing up the rpm's, no rattle...no rattle under load, back off throttle, good vacuum, it rattles... runs great, great oil pressure...valve train appears to be functioning properly... I am leaning towards lifter or valve spring problem... newer valve springs on motor that has about 30,000 miles on it... i cannot hear it when it idles, only goin' down the road... it is getting worse, i think i can actually feel it, but it is an off road rig that is pretty rough, lots of rattles and squeaks, hard to tell for sure...
engine rattle
- Thread starter breakit
- Start date
moldman05
Well-Known Member
- Joined
- Jan 27, 2006
- Location
- Rocky Mount NC
Maybe something loose inside exhaust such as heat riser valve or baffle in muffler.
rattlecanpaint
Well-Known Member
- Joined
- Apr 18, 2005
- Location
- Winston Salem
Check your accessories (Alternator, p/s pump etc.) I've seen slightly loose p/s pulley sound like a rod knock.
ncjeepers
Well-Known Member
- Joined
- Apr 13, 2005
- Location
- Locust, NC
A valve train problem should not be load dependant. You would most likely hear that all the time.
If you only hear it going down the road at light loads, the first that comes to mind is driveshaft vibration (u-joints, bad angles, etc).
If you only hear it going down the road at light loads, the first that comes to mind is driveshaft vibration (u-joints, bad angles, etc).
BUCKEYE PERFORMANCE INC.
BUCKEYE PERFORMANCE INC.
- Joined
- Dec 3, 2006
- Location
- swannanoa
does it rattle sitting still no load if u slowly bring rpms up and feather back off of it ? if so may be a piston or wrist pin.