I just bought a 96 T/A from a guy yesterday, and it had a cracked radiator. I drove it home, and even with the cracked radiator it wasn't overheating. I replaced the radiator yesterday afternoon, but now the car is overheating. I have noticed that my fans are not ever coming on, I plugged everything in right, I don't know what is going on. It doesn't overheat on the highway when it is getting airflow, just in the city because there is no airflow without the fans running. Can anybody help?

 

I just did the same exact thing that you did. After I got done replacing a new opti, I ran it and antifreeze was spraying everywhere from where you fill it up at. Turns out I had a cracked radiator, so the smart thing to do is replace it. Did that and now my car too is overheating unless on the highway. When its getting air its fine when going through town it heats up real bad. I seen that my fans also aren't turning on so today I'm gonna hook up a toggle switch straight to the fans so I can turn them on and off manually. I have to work the next 2 days so it may be alittle before I get back to you but I'll let you know how it turns out. Wouldn't be a bad suggestion so your fans stay on and cool everything at all times instead of periodically. Good luck

 

make sure that you bleed all the air out of the lines with the t-stat housing and the heater core line. next make sure your fans are working. stock LT-1 fans come on at almost the next line after the 210 line. its 226* and off at 221* i think

 

http://shbox.com/1/4th_gen_tech2.html#cooling

 

Ok, I have fixed the overheating problem, I replaced the temperature sensor that plugs into the water-pump and now the fans come on. But now, the car is running SO rich that it burns my eyes, and it stumbles and wants to die, when it dies I try to start it, and I have to give it some throttle to get it to start, then I put it into gear, start letting the cluctch out, and it starts jumping real bad, and I can be doing 30 to 40 mph in like 2nd or 3rd gear without my foot even on the pedal, and it will just start jumping like crazy. I am totally stumped. Anybody got any ideas?

 

I assume you replaced the ECT (Engine Coolant Temp sensor).

Test the IAT (intake air temp sensor). As I understand it, if the car thinks the air is really cold, it will increase one of the factors which is multiplied by the mass air sensor's reading of incoming air volume/velocity. In other words, if your IAT is bad, and the car thinks the intake air is like -40 degrees, it'll dump lots of gas in to compensate.

Also, you should check your O2 sensors, (assuming it still does this after it warms up), because the car uses the readings from those to adjust the Air/Fuel ratio (once the exhaust gas temperatures reach ~500 degrees.

If both of these are OK, the mass air could theoretically be bad.. but thats doubtful.

If all the electrical checks out, check your fuel pressure, ensure that your injectors are the correct size for your application, and make sure they aren't leaking.

That should be enough things to check for now.. Good luck!

Well.. one other simple thing I can think of to check.. are your cyls firing correctly? Do you have hesitation?

If you have an arcing plug wire, you might have wholly or partially uncombusted gas on a cyl or two, also, if you have incorrectly gapped or old plugs, you could have the same problem. You would probably have hesitation if this were the case. Oh, and speaking of ignition, don't ever let anyone scare you into buying a new opti until you are SURE thats what it is... Anyway.. again.. good luck, and let us know what you find out.

 

That sounds good, thanks for the help. I am going to try and get it to Autozone today and get it scanned and see what codes it is throwing because my SES light is on. I am guessing it is the 02's because the car didnt do this when the temp sensor was bad, so it was stuck in open loop. But now that it is going into closed loop, the 02's might be bad, and causing the computer to get false readings and run like crap. I will let you know what happens with the scan today.