Running hot, what's normal?
 

I have a 95 z28 6-speed. It ran hot to start with, but upon inspection the coolant was like 10% antifreeze. So I did a back flush, and replaced the thermostat with the stock 180deg, then refilled with a 50/50 mix ( ok maybe 55% antifreeze). It still runs hot, but not as bad as before. As long as I keep moving it sits just above 185, but in light to light traffic it can get up to 235 and sometimes a little higher. I have the factory maintenance manual, and I followed it when I filled the motor with coolant so I am pretty sure there is no air pockets.

My concern is, is this normal ( I imagine it's not). What temp should it stay at. What should I check for next? Would a set of FAL fans and lower temp fan sensor solve this?


Thanks for the help.

RE: Running hot, what's normal?
 

These cars run normally hot in traffic. The thermostat opens at 185; however, if the car is moving slowly the temperature will continue to rise until the fans are turned on by the PCM. Low speed comes on at 225 and high speed is set to come on at 232.

RE: Running hot, what's normal?
 

so then it's acting normal? I just got backing from running errands and I had stop and go traffic. I got just above 210 at the hottest, then cooled down once I got moving. No coolant boiled over from the resivoir bottle though, so it's better than it was.

If this is normal, then I am good for now, but I will have to look into upgrading the radiator to an all aluminum, with FAL fans, lower temp fan switch, Oil cooler (if it doesn't already have one, I haven't looked yet). I am used to cars that warm up and stay at or close to the same temp unless something is wrong......camaros are a different ballgame......but of course I love driving this thing around.

RE: Running hot, what's normal?
 

The fans are computer controlled, the elegant way to turn them on sooner is to reprogram the PCM.

RE: Running hot, what's normal?
 

or you can install a swich for the fans.

RE: Running hot, what's normal?
 

I would like to keep it controlled by the pcm, doesn't lt1 edit do this?

RE: Running hot, what's normal?
 

LT1 Edit can do it, and so can any of the hand held programmers, such as Hypertech.

RE: Running hot, what's normal?
 

Yeah, I saw that hypertech and some others could, but the handhelds won't delete the air pump or egr or vats......So rather than buy 2 units for a few hundred $$$ a piece I would rather just buy one.

RE: Running hot, what's normal?
 

Don't delete the EGR or the air pump if you intend to have the car pass inspection. The AIR pump only works during engine warm up to light off the cats faster, and the EGR only works at part throttle and you will not gain any power by deleting it.

RE: Running hot, what's normal?
 

I don't have emissions inspection where I live so I don't have to worry about that. I plan on removing the cats when I do the exhaust. Also when I do the exhaust I will do the headers, and having to not get headers that have the connections for emissions will open up a larger choice in headers. Then of course there is the slight bit of space that those parts clear up.