I just got done doing my timing chain and installing a new radiator. Nothing is leaking, all the hoses are connected. Why is it running hot? I installed an unorthodox lightened underdrive crank pulley so my water pump is spinning slightly slower- could this be the culprit? the car doesn't overheat, it just runs really hot. when i turn on the heater full blast, the temperature gauge levels out. any ideas?

I just got done doing my timing chain and installing a new radiator. Nothing is leaking, all the hoses are connected. Why is it running hot? I installed an unorthodox lightened underdrive crank pulley so my water pump is spinning slightly slower- could this be the culprit? the car doesn't overheat, it just runs really hot. when i turn on the heater full blast, the temperature gauge levels out. any ideas?

well, underdrive pulleys make the rest of the belt driven parts on ur engine spin slower, allowing the crankshaft to spin more freely, loosening up some unsung horsies. so yeah, that could very well be the problem.

but there are always others.

would putting a lower than stock temp thermostat on fix the problem?

would putting a lower than stock temp thermostat on fix the problem?

actually, that would probably be a good idea.. cause the thermostat is spring loaded to open once it gets to a certain temp, so if ur car is running HOT but not OVERHEATING, then it can be because the thermostat isnt opening as the engine is getting hot, but only opens once it is near overheating, so having the engine run cooler, and earlier, could be the fix to ur problem.

i don't think a lower temp thermostat is going to do it. yeah, it will open sooner and let coolant circulate sooner, but it will only make the system run cooler than normal until the engine heats up to the temp that a stock thermostat would be open anyway.

maybe a higher pressure rad. cap would be enough to do the trick? that is, if the problem is the underdriving of the waterpump.

i don't think a lower temp thermostat is going to do it. yeah, it will open sooner and let coolant circulate sooner, but it will only make the system run cooler than normal until the engine heats up to the temp that a stock thermostat would be open anyway.

maybe a higher pressure rad. cap would be enough to do the trick? that is, if the problem is the underdriving of the waterpump.

my friend has a nismo cap that makes 1.3 kg/cm2 pressure.

the greddy one is rated at 1.0 i believe

and he told me stock is 0.9 or 0.7 i cant remember worth a shit.

I just got done doing my timing chain and installing a new radiator. Nothing is leaking, all the hoses are connected. Why is it running hot? I installed an unorthodox lightened underdrive crank pulley so my water pump is spinning slightly slower- could this be the culprit? the car doesn't overheat, it just runs really hot. when i turn on the heater full blast, the temperature gauge levels out. any ideas?

You didn't state whether it is running hot at idle or on the road. I'll assume by the heater fan statement that the problem is at idle.

Most of the modern waterpumps have turbine style blades in liu of the old paddle wheel style, so the flow volume is cubed law with respect to rotational velocity. In other words, a reduction in rotational speed of 10 % results in a 27 % reduction in flow. (.9^3=.729). You can aid this flow by inducing a convection flow by running the/an electric fan at a slow speed at idle. (a piece of useless trivia: the original design for the 1932 ford V8 used no waterpump, but relied on convection flow for cooling) I have more on a FAQ at my site:

www.dccontrol.com

the car would run hot all the time, idle or driving. i fixed it, though. the liquid gasket i used (brown permatex) sucked and didn't seal tightly. i took it off and used nissan silicone and it works beautifully.