Ever since I changed the water pump and antifreeze, my engine seems to be running about 5 degrees hotter. I used 70% Antifreeze and 30 % water as the maxlife container said to. Any ideas what would cause this?

did you check the thermostat?

what condition is it in?

replaced my 195 t-stat with a 180 t-stat last August, 2003

did you read the mix right? the ZEREX Red that i use has 33% Antifreeze and 67% H2O for the optimum mixture.

As Mark said antifreeze is not the best heat transfer liquid it only gives the water better heat and cold levels. Atleast that is how i understand it - in a non-scientific sense.

Yeah the max life said for maximum performance to use 70 % anti and 30% water.

50/50 is the best mix for cooling (actually 100 percent water is the best thermally but boilover and rust is bad as well as freezing in the winter).

50/50, Stant thermostat (drilled if possible with 1/16 inch holes.....2 of them so one doesn't get lonely), and burp the air out of the system. You didn't get any debris from the old gasket/seal into the lower intake when you cleaned it, did you?

I dont think I got any dirt in the system when I did the water pum. I will drain some antifreeze and replace it with water and see if that helps any.

Sorry, i had my numbers backwards.

But, here is the deal with antifreeze . . . as most of you know (and as Rogue said) water is the best for transfer of heat as it is "wetter" than the antifreeze. the primary purpose of the antifreeze is to increase the boil-over and freeze points. the 70/30 mixture gives you the best boil over and freeze capabilities (around 276f and -64f), BUT it does not give you the best heat transfer. the glycol does this by contaminating the water. it is much the same as if you try to heat plain water compared to salt water. the salt water because of the "contaminate" salt, will boil at a higher point and freeze at a lower degree. The second thing that antifreeze does for us is to aid in keeping the coolant systemfree of rust. if you ran pure water your engine would rust (of course the aluminum wouldn't but you get the idea). the cleaners in the antifreeze help keep unwanted contaminates off the radiator which aids in heat transfer.

With all of that said, why do they recommend 50/50? well, it gives you what the industry considers the best of both heat transfer and corrosion resisitance. by moving your percentages from there you can add more corrosion and boil over protection by increasing the antifreeze or you can increase the heat transfer by adding a higer percentage of the water.