slow coolant leak from back of engine (passenger side)..appears to be coming from up high around head. Coolant lines to heater core not leaking. Anybody have a suggestion before I go ahead and assume its a leaking head gasket?

 

Clean that area thoroughly, perform a pressure test, and verify with inspection mirror.

 

already used inspection mirror..it appears to be coming from intake manifold side of the head..and its jammed up against firewall..going to be hard to tell exactly where its coming from.

 

Vigilantly monitor coolant expansion tank level and engine coolant temperature.

Keep coolant available in the vehicle to top-up as needed.

Have repair shop confirm head gasket failure using a pressure test.

If conditions worsen you may need to park the truck until repair can be made. Repeat overheating may cause the leak to worsen.

 

It could just be the valley pan gasket, I've heard this is a common gasket failure.

 

i've been checking expansion tank everyday, and keep a bottle of 50/50 mix in the back, looking for a pressure tester to borrow.

 

velley pan gasket just seals the intake manifold doesn't it?

 

Yes sounds like an intake gasket, they always leak.

 

Napa sells a dye kit that I used to find my leak. Put the dye in the expansion tank and use a black light to find the leak. I needed a mirror as well to get behind the engine, but I found the leak on the back of the heads.

x2 on the valley pan gasket, also a common leak area.

 

The lower manifold gasket seals the lower intake manifold to the engine block intake sides of the heads.

Attached is diagram from page 30-2-2 and 30-2-3 of the RAVE manual for reference.

Sorry for the size I am still learning.