Car was over heating on me had a cheap autozone plastic radiator and the fan wasn’t to strong . Now has all aluminum 3 core radiator new hoses 3000cfm fan when engine was out in all the gaskets were new. The block is not cracked no leaks from anywhere. There is no coolant mixing with oil or anything . What can it be it internal in the engine ? I’m not a mechanic don’t know what to do. Also the gauges don’t work on car as it has a sbc 350 600 edelbrock carb in it now. I out an aftermarket cheap temp gauge from autozone it goes up to 240 . And I shut it off I didn’t let it actually boil over

 

So first thing first... Is the "overheating" real?

You put an aftermarket gauge on the car... did you simply hook it up to the factory sender? Or did it come with it's own sender? The sender has to be matched to the gauge or you'll get a false readng.

Assuming the gauge set up is correct, we need more information.

Is this issue new? I..e, was running fine with this setup earlier, but now it's not? Or did it start having issues after you changed something?

Does it overheat while driving at moderate speed or just at low speed and idling?

The Autozone radiator itself is most likely not the problem (assuming it's not plugged or clogged with gunk). I'm running an "Autozone" radiator and it's doing just fine with a ~400 hp engine with A/C on in traffic in ~100F weather.

Is your front air dam (under the front bumper) present and in good condition?

What kind of fan is this 3000 CFM fan? Electric or mechanical? Can you take a few photos of your fan setup?

Btw....other non cooling system related causes could be too lean a fuel mixture or too much ignition timing...

 

The car is running hot just sitting in drive way idling. The lower dam piece is in tact in the middle but not on the sides. The fan is electric fan that comes on as soon as engine comes on. I bought it on eBay it’s not a great fan but it says it pushes out 3000cfm . The gauge is going right into the block . I tried adding a thermostat to see if that would help it hasn’t. If you drive the car it gets hot within 4-5 blocks idling I’d say 7-8 minutes and it’s pushing 240 . The water pump is new took off the upper hose it’s flow strong out of it. With cap off you see radiator moving water thru .

 

Only one way to know for sure is to borrow/buy an infrared thermometer and verify it. Can be had for not a ton of $$

 

So it sounds like this is a mechanical water temperature gauge. Let's assume for the moment the temperature reading is accurate...

Some basics to verify...

1.) Polarity on the fan electrical connection is correct (i.e., it's not spinning backwards). Do you get a rush of hot air if you put your hand between the fan and the engine?

2.) Fan is right up to the radiator (i.e., there isn't some large gap between the fan and the radiator)

3.) You have a 50/50 mix of water and anti-freeze

4.) You didn't accidentally get a reverse rotation water pump (i.e., later model 3rd gens went to a reverse rotation pump with the serpentine system)

5.) What temperature thermostat did you get?

 

Yes fan is up against radiator and I can feel warm air between fan and engine block . The thermostat is a 185 . As far as the water pump I’m not sure .

 

Without utilizing the harness I can go back to the original factory fans and just wire them to fuse box to come on immediately or do the only work with the harness . I don’t have the original engine it’s a sbc 350 now

 

My earlier question about when this problem started...

Is this issue new? I..e, it was running fine with this setup earlier, but now it's not? Or did it start having issues after you changed something?

 

Check between the radiator and the a/c condenser for some dumb reason it gets filled with leaves

 

What I also did to my 91 z28 with the tpi on YouTube they have a video showing how to remove some of the plastic pieces it turns the car to ram air and frees up all that restricted air flow to the radiator