440 antifreeze loss

Another coolant loss question....

I've read a few past posts, here and on other forums regarding coolant loss, but I thought I could narrow my symptoms with the Chrysler experts here. 440 full FWC-I am monitoring coolant loss from the resevoir after running. I marked a line on the external, plastic reservoir and the coolant is not returning, it's lower, each time. I don't have blocking plates btwn riser and manifold, just what I was given, solid gasket from Osco. I tried simplicity first-replaced expansion tank cap. No effect. Burped system (a few times). No effect. Risers, elbows, swivels are 1 yr old.

When warm, I'm not seeing discoloration of exhaust discharge water (rainbow) when it hits bay water. Diapers under engine are clean. Oil has good color. Plugs have normal mocha color.

What else to try?

Get your self a coolant system pressure tester and pressure it up. look and listen for leaks. do this both cold and hot.

will

...."I don't have blocking plates btwn riser and manifold"

Meaning your manifolds are NOT coolant cooled?

Jeff

Thanks for the replies. Jeff, they are coolant cooled. You had replied to someone else where you ask them if they had a plate sandwiched between that gaskets so I was tyring to answer that question straight off.

Thanks again

I'm finishing up pressure test and after 20 minutes I lost 1 lb of air. Oil still has nice brown color and I'm unable to hear any obvious air leaks. Any other suggestions?

Sounds like youve got a leak. Pull off your exhaust hoses and the Inlet and outlet of the Raw water side of the heat exchanger and re check for leaks.