I finally finished replacing the head gasket on my 91 300e and i remember reading somewhere that you start the engine and let it get to normal runing temp. with the coolant top off and the oil filler top off so that there is no pressure on the new gasket until it swells. is that true? if so what about the timing chain tensioner? after being re-installed, doesnt it need oil pressure to ratchet into place, and will leaving the oil filler top off effect that?

thanks in advance

off sounds like urban legend to me. the book should tell you what to do with the tensioner. the only other thing is to let it get good and hot and check coolant level after the thermostat has opened. this will get rid of air pockets.

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.

You must let the engine come to operation temperature for 10-15 minutes minmum before pressurizing the cooling system. The crankcase pressure is insignificant. The chain tensioer does not need oil pressure to provide tention. I replaced the head gasket on mine 70K miles ago with probs.

It's not a bad idea to set the climate control to maximum temperature as well. This will open the mono-valve and allow the entire cooling system, including the heater core to be bled completely.