bearing knock

[speed1972]

Ok I need some diagnosis help. When the vehicle is cold and cranked up, it makes no noise. After about 15 minutes, once everything warms up, it starts knocking at idle. Wouldn't that be main bearings? or is there something else causing this knock?

thanks, Larry

 

[NKau]

I'm positive it's either rod or main; can't remember which one specifically does it just after warming up. Once it starts knocking it loses all power too right? Either way, that engine needs to come apart.

 

[speed1972]

I'm not sure either but I was hoping I could figure it out so I could know where to look when I take it apart... Anyone else?

 

[hllon4whls]

In my experience this is a cam bearing or possibly a spun main bearing. I spun a cam bearing. When the car was cold, it would not make a sound, when it warmed up, it couldnt have been louder.

 

[NKau]

What happens if you try to drive it when it's warm? If it's a main, it will be a total dog; might even stall when put in gear.

 

[hllon4whls]

What happens if you try to drive it when it's warm? If it's a main, it will be a total dog; might even stall when put in gear.

Dont think so. If a main is gone, it would still have power until it beats itself to pieces. Unless it starts to sieze. If it starts to sieze, then it wont last more than a few minutes.

Further explanation on my cam bearing issue. The cam bearing was causing an overall loss of oil pressure. Not that the bearing itself was making noise.

What ever it is, if you drove it, the damage is done. The more it runs, the worse it is going to be. Park it and get it fixed asap.

 

[NKau]

Dont think so. If a main is gone, it would still have power until it beats itself to pieces. Unless it starts to sieze. If it starts to sieze, then it wont last more than a few minutes.

Further explanation on my cam bearing issue. The cam bearing was causing an overall loss of oil pressure. Not that the bearing itself was making noise.

What ever it is, if you drove it, the damage is done. The more it runs, the worse it is going to be. Park it and get it fixed asap.

Must have been the rod bearing in my dad's case then; couldn't remember.

 

[speed1972]

i will check it out and let you know.. thanks