1994 dodge ram 1500 5.2 204,500miles (rebuilt with 100,000 on rebuild?)

alright.. i bought a 1994 ram. put in a transmission run it for a couple hundred miles and figure out this...

no oil or coolent leaks. but both seem to get low, coolent runs low quickly. i idled the truck for a few mins and noticed the upper hose looking like it was collapesing. i pulled the rad cap and it sucked in air and hose returned to it's round shape.

my question is.. could this be the result of the plenum gasket leak? i read where the gasket will allow oil to burn. i was thinking with the collapsing hose the engine is sucking coolent in and going out the tail pipe. but after reading i dont know it this is the case... i did'nt find anyone else with a related problem.

the engine performance seems to be alright. idles fines, so it seems. i'm going to check each cyl tomarrow for compression.

any ideas are great.. i hate to just throw parts at it.

 

i don't think the disappearing coolant would be caused by plenum, because the plenum belly pan seperates the oily lifter valley from the low pressure air intake.

to lose coolant into the cylinder would have to be an intake gasket or head gasket, or a crack in a thick part of the head (unlikely).

you could be losing coolant out the water pump or freeze plug.

compression test and/or coolant pressure test is a good start.