MaGzz28

Hey guys, I own a 94 z28. Well, its seems to have a problem.... my motor seems to be running hot. Everytime i hit a stop light the temp gaugue just sikes nearly all the way up and as soon i hit an open road it just goes back down... so I flushed my radiator and then put in a new 180 temp thermostat... And im still having prblems... (but since i change my thermostat to a 180. it runs alot cooler than it used to should i just try a 160?)

ss.slp.ls1

iTrader: (36)

The stock thermostat is 180.
Are you sure you bleed your system properly?
I would verify that your fans are coming on when they are supposed to; 226*F for the slow speed fan and 235*F for the high speed fan.
With factory fan settings, it's normal for these cars to sit at ~210-230*.

latindragons

Yeah, it seems like your fans aren't turning on. Check the relays if you notice they aren't turning on.

MaGzz28

well, is it normal to have this type of inconsistency? (going up and then spiking back down)

ss.slp.ls1

iTrader: (36)

Before I got my new stat and reprogrammed fans, my car would sit at about a quarter of the temp gauge on the freeway. If I sat idling, the temp would rise (not spike) and the temp would teeter at around 210-230 degress. Then once I go moving again and stayed moving consistantly, it would drop back down to around the quarter mark.

MaGzz28

The Fans do turn on.

Dadic 78

If your fans are coming on, and your temp is spiking, you should check for air in your system. When doing a coolant flush on these motors, it's important to bleed the air out of the system after the new coolant is added.

Let your car sit at idle, and when the temp guage spikes again, open the upper rad-hose bleeder screw slightly. This will allow the air in the system to escape, and drop your temps. You might have to repeat this a couple times to get all the air out of the system.

ss.slp.ls1

iTrader: (36)

What I would do is let the car cool down completely. Open up the radiator cap, open up the two bleeder screws. Put a towel over the opti as to not get any coolant on it. Fill at the radiator, once you see coolant coming out of either of the bleeder screws, close them. When you reach the top of the radiator, cap it off. Start the car, let it sit and reach operating temperature ~210 degrees. Then shut it off and let it cool down completely again. Repeat the process until the point when you open up your radiator after cooling down completely, it's full every time. If it never reaches that point, you likely have a leak some where. If so you'll need to get a pressure tester and find your leak.