1998 Jeep Grand Cherokee Laredo SE Straight V6 4.0L 4x4

I've heard on this NG about being careful when replacing water-pumps as the 4.0L has a reverse-spinning pump..? Can someone else confirm this?

If you had overheating problems, maybe you've warped the head, and have a gasket leak? Are the oil & coolant still their natural colors?

I'm no mechanic but it sounds like maybe your heater core could be clogged.

It sounds like your heater core or the line going to it may be blocked for one thing. This could explain why the car is running hot and the vents are blowing cold air when the controls are set for hot. I don't know if that could be causing the engine to run rough and vibrate though. When was the last time you flushed the system?

Nat Man

Check the plug wires and firing order... you might have two reversed.

Exorcism? __ Steve .

The spark plugs are all fine. We still can't figure it out. Thanks

We flushed the system before we did the work, the line is not blocked, we are going to check the heater core tomorrow.

We plan to check the heater core.

We have the water pump that says "R". We also have noticed air coming from a certain part of the heads, and I do see some oil leakage, I will try that as well (change the head gaskets), but the heads are fine, no clanking noise (Pistons) while we let it run for 1/2 hour.

Thanks

The water pump we installed has an "R" stamped on it, the coolant is the color that came from the container we purchased. The oil however we plan to chang tomorrow.

Thanks

We have installed the water pump with "R" the coolant is the same color from the container we purchased, however we are going to change the oil tomorrow.

Thanks