I recently picked up an 03 cobra that has a weird cooling issue. It will puke coolant out the radiator overflow reservoir (aftermarket canton or similar). However, the coolant it pukes is cold, almost like the thermostat is not opening. I removed the thermostat, it is an aftermarket "Motorad" one. Put it in a pot of boiling water and it seemed to open ok, reinstalled it, filled and burped according to the Reisch page, and it still puked cold coolant after 20 or so minutes of idling.
I rented a cooling system pressure tester and pressurized from the reservoir cap 15PSI. 20 minutes later pressure had not dropped at all so I assume tank and radiator are good. Fearing a head gasket issue I also bought one of those "block tester" kits that tests for exhaust gases in the coolant. I checked at both the coolant crossover and the expansion tank, no change in fluid color, so there does not appear to be any exhaust in the coolant.
I also did a compression test and all readings were healthy ~160PSI all within 10PSI of each other.
Kind of stumped at this point. Im going to try a stock reservoir and probably throw in a new OEM thermostat and try burping again. Should I possibly try running with no thermostat to see if that helps? Just seems to me that if it is puking cold coolant, I dont have any flow through the radiator. Anything else anyone can think of? Maybe a stubborn air pocket somewhere?
I rented a cooling system pressure tester and pressurized from the reservoir cap 15PSI. 20 minutes later pressure had not dropped at all so I assume tank and radiator are good. Fearing a head gasket issue I also bought one of those "block tester" kits that tests for exhaust gases in the coolant. I checked at both the coolant crossover and the expansion tank, no change in fluid color, so there does not appear to be any exhaust in the coolant.
I also did a compression test and all readings were healthy ~160PSI all within 10PSI of each other.
Kind of stumped at this point. Im going to try a stock reservoir and probably throw in a new OEM thermostat and try burping again. Should I possibly try running with no thermostat to see if that helps? Just seems to me that if it is puking cold coolant, I dont have any flow through the radiator. Anything else anyone can think of? Maybe a stubborn air pocket somewhere?