I have a 93 Z28 . My car loves to overheat at the worst of times , usually in heavy traffic and slow speeds. I must have flushed my engine at least 4 times . The fans are operating the way they should at the correct temp . I replaced the radiator , thermostat and temp switches , which did wonders for the car when on the freeway with lots of air flow but It still runs hot stuck in traffic . The air scoop under the car is still there and hasn't been removed . Not sure where to go from here . heater core ? I was even thinking about putting in a thermo switch for my fans or a regular toggle so I can turn them on when needed , but thats not a real fix to the problem ... Any suggestions ?

 

Forgot to mention ... Every time the coolant system was drained , I bled the system . :-p

 

it could be the steam pipe crossover in the rear of the heads is pluged. how bad dirty was the system whem you flushed it?

 

If its not those steam vent lines then try cleaning the AC condensor in front of the radiator, you may need to block up the front end , remove the radiator again , and get a pressure washer on it from the under side blowing towards the front, you will be surpised how much sand and small rocks are in it blocking the airflow. When i pulled my lt1 and cleaned it, i noticed this when some sand got into my eyes working on it, and where it was coming from because there was so much sand falling. If you can get a strong air gun on it , you may be able to blow it out without taking anything off !!


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

 

I'll give those two things a shot . How difficult is the cleaning of the steam vent lines ? The coolant was pretty damn dirty and I'm wondering if the heads are plugged up as well ...

 

I wish someone knew of a good flush that actually cleaned that sludge out, i cant find one either and i have tried every type at local parts stores with no luck. Even tried liquid laundry soap, alcohol, and removed a resorvor once and filled it with gasoline for two days, nothing would cut that sludge.

You will probably have to remove them to clean it.

Careful not to damage them, hard to find new ones.