Hey everyone, I have been chasing a cooling problem and I am looking for some help. Truck is 1993 K1500 TBI with vortec heads.

  1. What is considered the normal range for ECT?
  2. At what point would you stop the truck and wait for it to cool down?
  3. Could this be caused by me having the heater core hoses hooked up backwards? (I don't know for sure if they are - I just know that I guessed at what was correct when I put everything back together so I have a 50/50 shot that it is correct).


Any input/advice is appreciated.

AC

Some background.
  1. Cooling setup is stock (fans, radiator, etc.)
  2. New water pump
  3. Not running AC (broken)
  4. Thermostat is stock (190 or 195, can't remember but I do know I bought an OEM rated stat)
  5. I live in Atlanta, Ga. (it is hot here).
  6. Sometimes the truck will run in stop-and-go traffic and never crack over 210.
  7. Sometimes the truck will creep into the 220's but eventually it will cool back down into the 205-210 range. This usually happens in stop and go traffic. It is worse in the afternoons when it is hottest outside but still happens some mornings when it is cool (hot and cool are relative here and ranges from 70-90 degrees).
  8. Coolant overflow tank never seems to change level or even come into play.
  9. No steam/boiling/etc is seen or heard.
  10. No coolant smells.
  11. Coolant level in the radiator tank remains consistent (I check it some mornings when everything is cold)
  12. Engine was refilled with fresh 50/50 after the rebuild was finished in May.
  13. When I first started driving and tuning the truck it would slowly build heat until it could no longer cool (greater than 230). I would have to turn it off and wait for it to cool.
  14. I have since learned that the stock TBI timing tables are nowhere near advanced enough for the vortec heads.
  15. Changing the main timing table TREMENDOUSLY helped the drive-ability and mostly helped the overheating problem.
  16. Still, the ECT will randomly creep up. For example today the ECT hit 227 on the way home in stop-and-go. This was after about 35 minutes of stop-and-go
  17. The truck runs "rougher" when it is over 210. Not sure if this is fuel or timing related.