Engine/Transmission (1998.5 - 2002) Heater doesnt get hot!

[Ragain]

Here's a thought... how many of us have the OEM head gasket still on their block? I understand it's been a common problem for them to "wash out" on the front passenger side corner of the block (above the water pump). When I finally replaced my head gasket, the heat could run me out in 0° weather. If a leak is bad enough that no pressure would build on the coolant system, could that be a culprit? Tight radiator hose= heat? That seemed to be the case for me. I reused my t-stat that was a month old, because replacing it alone didn't give me cab heat. I replaced the head gasket and had plenty of heat.

Cummins rep told me purpose for the tiny coolant passage hole in heater hose fitting vertical out of the head was to purge air out of the coolant system.

Also, if there is no shut off at the heater core, (controlled at the dash), wouldn't heat blow through ducts year round? I am not sure on that one, because I haven't studied that section of the service manual yet.

 

[LDPetersen]

The thermostat fixed my no heat problem , but we noticed a tiny amount of leakage from the head gasket down to the water pump area. I do lose a small amount of anti-freeze but it is a very small amount . Must be that head gasket starting to go. It has been -30 deg. here for a week so i guess i will wait a while to dig into that. I did an oil sample test to be sure it is not going into oil.