Hey, I just bought an 86 with over heating problems for $80. i was outside looking at it and the hose to the heater core is just looped back to the heater return line. could this contribute to over heating? like creating a loop of coolant that doesn't pass through the radiator? especially if the radiator and fan are sub-par? the car has 201K miles, so i'm just assuming they are sub-par. there aren't any leaks and the exhaust does not smoke or smell like coolant, so i don't think the water seals are gone. going to see if i can rent a coolant pressure tester or borrow one from a shop in the near future.

ps. this car is hoping to be a track car someday, only if i can get my **** together, so the heater is coming out of it anyway. could i just cap off that coolant exit from the engine without any adverse affects?

 

Yeah. That's not rigged right. Cap both off. It's not helping things.

 

Hrm. If it were me, I would lead it back to the heater. Have you flushed the coolant and the system with a good flush product? I hear Purple Power degreaser works very well.

 

I am not going to put it back to the heater unless capping it off is going to mess something up. i have a daily driver and i can do whatever i want to this car. anybody have any suggestions for how to cap it off? i was thinking short piece of hose with a bolt in it and a hose clamp. any better ideas out there?

 

That's not the cause of the problem.

See http://www.aaroncake.net/rx-7/cooling.htm

 

i've read your cooling page, but it does create a loop of water that does not pass through the radiator. and i was thinking the water might follow the path of least resistance and just take that route the majority of the time.

i do suspect some pressure loss through old hoses is part of the problem as well, but it overheats under all conditions so i'm hoping this is the big part. i can feel a little water in the upper radiator hose after letting it warm up, so the water pump seems to be working. i have the belly pan and it gets hot on the freeway so it shouldn't be the fan. the radiator is extremely clear of debris and the thermostat is new.

 

after thinking for a minute i realize that without water going through the radiator there really wouldn't be any pressure to push the water through again... so some is going through the loop still, but probably not enough to cause it to run all the way up the guage...