I've noticed over the last few weeks my engine temp would get to about 210 when I stop and 190 when driving. I have a 3" body lift and I figured the problem was the fan was lower than the radiator. I ditched the fan and installed a new 16" electric fan. ( the auto temp switch is suppose to come on at 185 but it seems to be defective, I'm running it on a toggle switch right now). Now it averages about 190 at idle with the fan. I installed a new temp gauges also. But the temp gauge does not rise as the temp gets higher, it just jumps all at once to the current temp (about 185). The previous owner installed a motor out of a 93 z71. Sound like a regular operating range? I'm not sure if it has a tstat or if it's stuck. As soon as you start the engine water is flowing.

 

t stat is cheep and easy , never just take one out , try flushing the radiator with a good cleaner , if you get much dirty water you may need a new one . about $125 at autozone. I just did this and after 2 complete flushes it still ran out mud when it took it out .

 

I'm working behind the previous owner involving the tstat. I'm leaning toward it having one because I do not get any temp reading. It seems it opens around 180-190 and temp shoots up from 0 to that level. And water color is good. I tried it again today. It runs 190-200 driving without fan running and 210-215 sitting still with fan on. Getting to hot or sound like a decent range?

 

16" fan may not pull enough CFM of air to do a complete job of cooling at idle. you should have at least 2500 CFM. try moving the fan to the inlet side of the radiator. that might help. you didn't say if this full sized or little blazer... my son and i had to put a dual fan set on his full sized and a 383 stroker to keep it around 200 at all times. FWD engines kick the cooling fans on about 235. so 210-215 at idle should live..

 

Sorry bout that. It's a 84 full size with a 93 5.7 ( carbed). CFM's being moved is 2200. There is not enough room for 2 16" fans and when I removed the mech fan I was getting the same results. Everyone I talk to keep saying my max temp should be around 180.

 

Check the timing , if it's high it will run hot . Also could be lean at idle if you have modifications to intake or exhaust. Try closing the choke to see if it cools down .

 

we used a 16" and a 12", set one to come on around 200 the other at 210 with a 195 degree stat. Your carbureted so your not using the computer for fuel or timing management, CORRECT??? if so put a 160 stat in it and see what temp the engine seeks.
if it stays cool on the open road and not at stops, it either air flow across the radiator, mud outside the radiator or corrosion/crud built up inside the radiator.
my venture van didn't need a radiator, but i was putting a head gasket on the back side and a AC condenser in it. the AC condenser required removing the radiator/condenser as a unit and unbolting them. i decided a radiator was in store for a long term fix. it ran 10 degrees cooler after that. i was surprised at that, but when i removed the tanks of both ends i sure understood why...

 

I'm installing a new t-stat tomorrow. If that doesn't fix the problem I found a 4 row aluminum radiator that's decently priced. I'll post the results. Thanks for the help!

 

Ok here's the latest. It had a 160 tstat, I installed a new 180. Temp rises to 180, tstat opens up and averages about 180-190 with no fan. Parked and idling after a 10 min drive with fan running it average between 195-200. One thing I did notice, there was a bit of water spill on the intake and pooled between the intake runners. When I was looking for leaks I noticed at the #4 location ,water was boiling on the intake but no where else. Blockage? I'm going to to pull the spark plugs and see if #4 is buring hotter. Open to advice