Hello everyone, I just signed up to the forum.

I have a '99 LHS (3.5 v6). About 2 years ago, my water pump locked up causing my timing belt to melt over time until it snapped. It was pretty bad damage. I had to replace the starter, tensioner pulley, crank sprocket, water pump, thermostat, all belts, 3 exhaust valves on the left head and have it shaved off since it was warped. The car was running great, getting great gas mileage however i was experiencing some cooling/heating issues.

During winter, it would never get hot unless I came to a stop and let the car idle for a while. During summer (now), the car has been running hot. Finally it gave out on me last wk, overheated and started "clicking". Before taking the engine apart, I did some tests: good compression on each cylinder 150psi+, max of 13% loss on the leak test, oil on most of the plugs.

I took the heads to a shop to get them checked. They did a compression and a vacuum check; found out that some of the valve seats were leaking. Afterwards, they saw a few chips on the lobes of the right cam so replaced it. They also put all new valve seats and fixed 4 of the guides that were loose. I replaced the water pump and tested the thermostat, which seemed to be working fine. I also saw that 1/8" of the timing belt was literally shaved off on the outside perimeter; I have no idea what caused it.

Anyways, before I start putting the car back together, I'm trying to figure out the cooling/heating problem. I'd hate to put it back together and break down again. I'd appreciate any help.