engine knocks when started

[clizz3]

Just like what the title says, engine knocks when I start the car. Bad main bearing or rod?

 

[boost97gst]

Usually? Yes, a rod bearing is bad. Main is possible too and would make an even deeper "thumping" sound.
Post a video and that will help people to diagnose it better.

 

[97_4g63t]

When I spun a rod bearing I could pull the plug wire on that cylinder and the knock was drastically quieter.

 

[bryanwheat]

Impossible for any one on this broad to diagnose. Pull the pan and check it out.

 

[92AWDHX40]

When I spun a rod bearing thump and she stopped.

 

[clizz3]

Ill post a video in the morning. Seems to only knock on a cold start. Any other times it doesn't

 

[92AWDHX40]

A video would be great, I never had a engine knock before, and Ive had a few dsms, and plenty of vehicles.

 

[clizz3]

Everytime I go to start the car it doesn't knock anymore.

 

[92AWDHX40]

Oh well maybe its ok.

 

[boost97gst]

^, hey, i guess ya never know right? Sure would be nice for the OP. I know the gut wrenching feeling you get when you hear rod knock. Not fun. OP rev to 3k rpm in neutral and tell me if the sound is much louder or more noticeable. 3k is like the magic rpm for rod knock detection. When mine started knocking i never let it get to the point where i could hear it at idle, only at ~3k rpm was it noticeable. Then again, my bearing was not spun. A crank knock is a distinct "thumping", not a knocking. Never heard crank knock in a dsm but have heard in other 4cyl engines.