- Location
- Near Rochester NY
2000 XJ, 4.0L, 120,000 miles Everything stock...
I'm a little rusty at diagnosing piston slap. Not to date myself, but the only engine where I have heard it was the 292 cuin 6 in my 1955 Chevy Sedan Delivery... Gee I wish I still had that truck.
I have been chasing this noise for a couple of months that I thought was a sticky lifter. I fed it Lucas oil additive, Marvel Mystery Oil and some other stuff too. The sound has gradually gotten worse, not better. Then after reading several posts here, I thought it could be a cracked flex plate or loose TC bolt. I verified the TC bolts and bellhousing to engine bolts are all tight, and there are no cracks in the flex plate.
Symptoms:
I get a rather loud knocking noise when the engine is cold and under load. It is hardly noticible if the engine is idling cold without any load. I went over the engine this morning with a stethascope while a friend held the throttle at 1200 RPM in drive, with his feet on the brakes. This is what I observed:
Is this a typical set of symptoms for piston slap?
Would a piston slap be louder on the drivers side, since that is the side where the piston is traveling down after ignition?
Is 2000 one of the years that Chrysler had trouble matching their engine bores to piston size?
TIA,
MoFo
I'm a little rusty at diagnosing piston slap. Not to date myself, but the only engine where I have heard it was the 292 cuin 6 in my 1955 Chevy Sedan Delivery... Gee I wish I still had that truck.
I have been chasing this noise for a couple of months that I thought was a sticky lifter. I fed it Lucas oil additive, Marvel Mystery Oil and some other stuff too. The sound has gradually gotten worse, not better. Then after reading several posts here, I thought it could be a cracked flex plate or loose TC bolt. I verified the TC bolts and bellhousing to engine bolts are all tight, and there are no cracks in the flex plate.
Symptoms:
I get a rather loud knocking noise when the engine is cold and under load. It is hardly noticible if the engine is idling cold without any load. I went over the engine this morning with a stethascope while a friend held the throttle at 1200 RPM in drive, with his feet on the brakes. This is what I observed:
- Timing chain and water pump were quiet
- Noise was most evident about 2" to 3" below the head gasket on the passenger side
- The only noise on the driver side of the head was the valve and injector clatter. I can't get the probe into the drivers side below the manifold.
- After about 3 minutes of running (30*F ambient), the thermostat housing was 140*F (with IR gun) the noise was barely noticable under load.
- In 5 minutes the noise was completly undectable
Is this a typical set of symptoms for piston slap?
Would a piston slap be louder on the drivers side, since that is the side where the piston is traveling down after ignition?
Is 2000 one of the years that Chrysler had trouble matching their engine bores to piston size?
TIA,
MoFo