94 dodge ram b250 v6 3.9l

so iv had this problem for about 2 months now, ever since i got my 94 back on the road. I changed the water pump because the pulley was bad. i thought that was like knocking sound...but it wasnt.

here how it is..its a deep knocking sounds. nothing high pitch. its a slow knock. when im ideling its pretty bad. when i pull off it sometimes acts like the engine wants to cut off. only had it stall 2 times on me in 2 months. i was wondering if anyone can tell me what my problem is. thanks alot

 

Welcome to DF
I'm going to move your post to the Ram Van section.

 

How is the noise affected when you drive?
Is the noise different when the engine is cold versus hot?

 

Is this a daily driver around town or do you get it out on the highway at freeway speeds for extended times? Could it be a pre-ignition knock?

 

I drive it to work and back about 3 miles one way. I drive it on the freeway about 2 times every 2 weeks. Someone told me i might have bad lifters or push rods. I have a rebuild book for this van and they seem pretty easy to replace. i dont think its a bad lifter tho or i would feel it when i put my hand on the value cover..

 

The noise is effecting the drive by poor acceleration. it knocks the most in idel and when i take off. once i get to speed of 35 to 45 mph the knocking isnt as bad. the engine was over heating when my water pump went bad. maybe it heated up the push rods and bent them?

 

and the temp of the van does not effect the noise.

 

Sounds like you spun the rear main bearing.

 

How do I go about checking the rear main bearing and where is it located.

 

You have to drop the oil pan and remove the rear main bearing cap. It's the rearmost bearing holding the crankshaft in place.