I recently bought a 2001 Dakota 4x4 quad cab with the 4.7 V8 and auto trans, I got it for $700 cash and drove it home. It has a knock that can be best heard in the driver side fender well, the thing that puzzles me is it goes away after the motor is completely warm or is revved above 2000 RPM's give or take. My question is if it is a rod then why does it stop knocking when warmed up or above 2000 RPM's, and if not a rod what could it possibly be? I have read a lot of the post about this issue and the numerous things it might be but was just checking to see if anyone had any other opinions. I haven't had time to crawl around under it yet due to work but plan on going over it with a fine tooth comb after the 1st of the year. Thanks for any help.

 

Get a mechanics stethoscope, and see if you can localize where the noise is coming from. You might get lucky, and it's just a lazy lifter.

 

That would be nice. I'll have to pick one up and have a listen.

 

Broken exhaust manifold bolts??? maybe

 

Did some checking when I got home from the deer camp and I'm 95% sure the knock is coming from the catalytic converter on the driver's side. I can grab it and hold pressure on the shield and the knock gets quieter. It's like it has come loose on the inside and while the truck is idling it is falling to the bottom, and when you rev it up it has enough pressure to hold it up and it quits knocking.

 

If that's the case, get under there and bang on it with the side of your fist (while cold of course). Should rattle pretty good if the substrate has crumbled. I've used Walker cats for other cars, which came with 5 year warranty.

 

I am assuming that sense you can get the complete exhaust system from the manifolds to the outlet of the big cat including both small cats for around $250 it would be best to install new instead of deleting the cats and causing issues, would this be a correct assumption?

 

Legally, you need to have the cats on there.....

If you have emissions testing, or visual inspection, you will have to have the cats on there.

I don't know of anyone that has gotten busted for NOT having cats on their vehicle...... (provided where it was registered, they don't do testing/inspection.)

Granted, I don't think you would save much money getting an 'off-road' y-pipe.....