I've been fighting the temperature in the Malibu both driving and idling...…….Mostly idling. New Champion 3 core, 16 pound cap, two 12" electric fans, and a FlexOlite 418 flex fan. Usually when driving it would settle in at around 190F. When getting on it hard it would go up to about 195-200F and then return to normal. When idling in the driveway it would move up to 220F+ after a few minutes. A little driving and it would come back down.
I did a couple of things, but only one thing at a time.
The engine is a 519" Cadillac. These engines are known for running hot. The thermostat is an old Stant 332-180 high flow. The water pump is an enclosed back $35 remanufactured unit. There is a very large GVW trans cooler attached to the front of the radiator that measures 12" x 10-1/2" at the fins.
First I replaced my Champion 3 core aluminum radiator with an Engineered Cooling Products 2 core aluminum radiator. The Champion has three 5/8" rows and the ECP has two 1" cores and larger tanks. Inlet and outlet diameters are the same. Pulley remained the stock 6-1/2". I pulled the dual 12" electric fans off and only ran the FlexOlite 418 plastic flex fan. The temperature driving at about 55mph settled in around 185-187F. When a power run was made the temp would go to about 195F and slowly return to 185F after about 1/2 mile of normal 55mph driving. Pull in the driveway and let it idle and within two minutes it is well past 200F. After about five minute it's at 210F. That's better than the Champion radiator and no electric fans. Decent improvement. Outside temperature 42F.
Second I pulled the stock 6-1/2" pulley off and put on the L78/ZL1 5-7/8" pulley with no other changes. The temperature driving at about 55mph settled in around 175-177F. When a power run was made there was no change at all, still 175F. At no point whatsoever did the gauge go past 182F and that was when the thermostat first opened. Several power runs and slower back road driving yielded the same results. Pull in the driveway and let it idle and after at least five minutes it never got past 188F. I revved it up to 1500rpm and it came back down to 182F quickly and I shut it off. Very nice results. Outside temperature 45F.
So my water pump and flex fan are somewhat faster than before and I believe that it would have made a big difference with the Champion radiator. I believe that the thermostat is actually doing it's job now instead of just staying wide open all the time. I still have electric fans to try but I just don't know if I want to mess with it as I'm pretty happy as is. With the hood closed, I can feel the cool air rushing with my hand in front of the grille and hot air being forced out as I hold my hand behind the cowl induction hood openings. The cheap plastic fan moves a lot of air.
Anybody having cooling issues would be advised by me to try overdriving the water pump pulley a bit instead of upsizing the radiator. I don't know how much HP it costs, or how much HP the temperature reduction my gain.
I did a couple of things, but only one thing at a time.
The engine is a 519" Cadillac. These engines are known for running hot. The thermostat is an old Stant 332-180 high flow. The water pump is an enclosed back $35 remanufactured unit. There is a very large GVW trans cooler attached to the front of the radiator that measures 12" x 10-1/2" at the fins.
First I replaced my Champion 3 core aluminum radiator with an Engineered Cooling Products 2 core aluminum radiator. The Champion has three 5/8" rows and the ECP has two 1" cores and larger tanks. Inlet and outlet diameters are the same. Pulley remained the stock 6-1/2". I pulled the dual 12" electric fans off and only ran the FlexOlite 418 plastic flex fan. The temperature driving at about 55mph settled in around 185-187F. When a power run was made the temp would go to about 195F and slowly return to 185F after about 1/2 mile of normal 55mph driving. Pull in the driveway and let it idle and within two minutes it is well past 200F. After about five minute it's at 210F. That's better than the Champion radiator and no electric fans. Decent improvement. Outside temperature 42F.
Second I pulled the stock 6-1/2" pulley off and put on the L78/ZL1 5-7/8" pulley with no other changes. The temperature driving at about 55mph settled in around 175-177F. When a power run was made there was no change at all, still 175F. At no point whatsoever did the gauge go past 182F and that was when the thermostat first opened. Several power runs and slower back road driving yielded the same results. Pull in the driveway and let it idle and after at least five minutes it never got past 188F. I revved it up to 1500rpm and it came back down to 182F quickly and I shut it off. Very nice results. Outside temperature 45F.
So my water pump and flex fan are somewhat faster than before and I believe that it would have made a big difference with the Champion radiator. I believe that the thermostat is actually doing it's job now instead of just staying wide open all the time. I still have electric fans to try but I just don't know if I want to mess with it as I'm pretty happy as is. With the hood closed, I can feel the cool air rushing with my hand in front of the grille and hot air being forced out as I hold my hand behind the cowl induction hood openings. The cheap plastic fan moves a lot of air.
Anybody having cooling issues would be advised by me to try overdriving the water pump pulley a bit instead of upsizing the radiator. I don't know how much HP it costs, or how much HP the temperature reduction my gain.
