Alright so it started when I had high oil temps and checked the oil. I was down a quart and had never had problems losing oil in any way. I filled it up and ever since the oil temp varies. It increases quickly to max out and falls to a steady temp, then keeps rising and falling as I drive. The heater also only works now when I'm driving on the highway. I had my oil changed and both these problems were resolved but about two weeks after there was a crack sound and the problems came back but I'm not leaking oil. I have no idea whats going on. Thanks for any help!

 

The factory gauge in the Instrument Cluster is Coolant Temp, if it is varying, first check coolant levels when cold in both radiator and overflow reservoir.

Fill the radiator and add to the reservoir up to the cold line. If the radiator was low, you will need to monitor the reservoir and top off for a week or two until the air is out of the system.

Your radiator cap is suspect if the radiator is always low but the reservoir is fine.

 

Great thanks a lot! I should've known that considering I changed the thermostat a couple years back.

 

Alright so it's most definitely the LIM gaskets. I know there are a ton of posts on here but I'm just wondering if there are any sort of specialized tools that are needed. I have a 2001 4x4 4-door 4.3 V6. Thanks!

 

The only "specialized" tool is an accurate inch pound torque wrench when installing the lower intake manifold bolts. It is mandatory that the bolts be torqued properly, and in the proper sequence.



Before installing the bolts, clean the threads on the bolts, and in the cylinder heads, with a tap and die. Then apply thread sealer to the bolts. The sealer will prevent the bolts from "walking out", (due to the low torque) from normal engine vibration.