Hello everyone!

I'm hoping what happened to my car is something someone here has experienced. I drive a 99 Grand am se 2.4. About a year ago I had coil pack housing fail to the point it caught the exhaust on fire. Compression was really low on 2 cylinders so I removed head it had very minor warp and valves were strong but bad carbon build up. Machine shop fixed it up for me. I put it back together with new coil packs and new housing it has ran beautifully until a week ago. I lost all acceleration and then car died. I did some research online and started diagnostics at the ICM plug and found that the crank sensor had no signal. I replaced sensor took car a while to start once it fired up I now have a very fast knock that increases with rpm's but here is the strange thing. If I bring rpm's up fast and let them drop fast there is a few second interval that the knocking stops. I need to mention that the engine isn't as peppy as before! Here is what I'm curious about. When I did the head funds were tight and I did not replace chain and guides. My understanding is the chain can slip maybe three teeth before valve damage occurs. Is it possible this has happened and it is lifter noise I am hearing? I did compression test I have 150 to 155 on all 4 cylinders. It's only been started a couple times so I won't damage anything further! Any ideas or comments would be greatly appreciated! Thank Heath

Did the old sensor look beat up?



"In Oldskool we trust"

Sounds like a classic #3 rod bearing on an ld9.



"In Oldskool we trust"

Sorry I did not reply things have been crazy! It turned out to be #1, #2, #3 rod bearings. Crazy thing is it never made a sound until I replaced the crank sensor. I tore it down and wow it was bad! I thought I had leaves in the oil pan but it was thin shreds of metal from the bearings. I had another 2.4 that I am replacing the crankshaft and all the bearings having trouble deciding how to put the new balance shaft gear on new crank. If any idea I would appreciate the advice. Thanks Heath