I'm in need of some ideas, advice, etc... I have a 91 Pickup with the 3.0 V6. It has just recently developed a knock at idle that grows louder as the truck warms up. I have ruled out any of the belt driven accessories. I listened wih my stethoscope to all parts top and bottom and the noise is definitely in the front of the engine and seems to come from under the timing belt cover (more on the pass. side) I've got lots of experience w/22R's, but not so much with the 6. I'm not afraid to tear into it, but I don't want to spend all weekend working on the timing belt if the engine needs to come out and be built. Has anyone else ever dealt with this?
Thanks, Wheelman55

 

From what I have come across, a knock in a 3.0 only spells bad news. Usually a wrist pin or a lower end bearing. When they let go, they can really let go big time.
It isn't an interference head engine so even if the timing belt was messed up, I don't there is anything that could "knock".
Keep in mind, I'm not a mechanic, just an obsessive info junkie that spent the last few months gathering info from the net on 2nd gen 4Runner and the 3.0 engine. The result of all my studying up; I bought a 4Runner with a 22re
Hope it turns out to be something simple.

 

If it seems to be coming from under the T.C. I would lean towards a bad water pump.

 

Ding- Ding- Ding---- We have a winner! Shaft bearing in the water pump is totally shot. Only had to tear about an hours worth of parts off to figure it out. Whole lot cheaper than a rod, though.
Thanks for the help.