what the idel spec is maybe 700. a lot are 700. yes your description of the hotness of all the gp seems to indicate other problems.

the compression checked cold is about 320 at sea level with a minimum of 220. tested hot it is higher i dont remember what exactly but over 400.

this problem doesnt sound compression related but never hurts to take it.

solve the algae first before doing any mechanical things, i think.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.