Hello Brain Trust, give me your thoughts on this.
My '85 Turbo Esprit is spitting out coolant, and I'm not sure why. I added a pressurized header tank and a recovery tank, but every time I run the car the full header tank empties maybe halfway, seemingly through the recovery tank, but does not draw the coolant back from the tank. I've tried different header tank caps, and the coolant in the recovery tank flows back to the tank if I raise the recovery tank above the (open) header, so that hose is clear, and does not seem to be collapsing with suction. The recovery tank is down by the battery, hopefully not to low to function as I think Lotus put it there on later cars.
I filled the car on a pretty good nose down slant, and ran it for a bit to try to circulate out any trapped air, allowing the coolant to warm enough for the thermostat to open. I puzzled by it's behavior- With a funnel sealed to the header tank fill, the car at idle will fill the funnel partway (~24oz?) as the car warms up at idle, and the tank contents are pulsing with the flow. The strange part is when I rev the engine a bit, it sucks the coolant back down out of the funnel, and when I let off it rushes back into the funnel. after the engine is off and it starts to cool it SLOWly draws the coolant out of the funnel and back into the header tank.
I wonder if I have a slug of air that expanding when heated and forcing out the coolant. My car does not have the radiator bleed in the top of the radiator, so I'm contemplating raising the right front corner as high as possible and loosening the upper radiator hose to try to get some trapped air out that way. I'm kicking myself for not adding a bleed fitting when I had the radiator out.
I've since raised the header tank 45mm to ensure all the air can bleed from the J pipe, but doubt it will help.
I considered a blown head gasket, and have a block checking kit on hand, but can't use it yet as the coolant level rising in the tank leaves no air to draw through the checker fluid.