Overheating | Radiator fan issues | 1985 Feiro GT (Page 6/6) theogre FEB 07, 02:19 PM quote Originally posted by Mike in Sydney: Disagree. #6 - 7 quarts? That’s half the volume of the cooling system. when I drain my system after flushing, I open up the drain plugs in the coolant tubes and take the drain plugs out. Doing this, I get most of the water out and start with a relatively empty system. Even if you think that... The block, heater loop & even the Rad holds enough water after Flushing so Never Use 50/50 mix to refill the system. Even when find & use block drain hole(s) often those won't totally empty the block. Most can't find them or too hard to use them for various reasons so block drains out whatever hose is lowest have more water. Heater loop have the heater core & more parts that doesn't drain easy if drains @ all. In Fiero the loop can easily "trap" 1/2 gallon or more depending year & engine setup. Fiero Rad holds More Water then most others when drained because of the angle it's mounted tilted forward. So will have Weak coolant causing "Rust" ("" because contains Iron rust, AlOx etc.) & more problems using 50/50. Example: W/ duke Fiero you never get to drain the block because the plug is blocked by other things like exhaust "shield" w/ "Fire" recall done. Even if you can pull it, any coolant is electrically conductive & right over the starter & solenoid. Had to relocate the air cleaner "pipe" just to take this pic... Purple w/ heat guard tape goes to the solenoid. I'm not sure you can drain enough more w/ that because right hose is so low. So several reasons why I & most others never bother to try removing that. So draining what you can, I fit 7-8 quarts of 100% coolant then top of w/ water. If I can't get last couple Q of 100% in main system, then dump last in O-flow tank. Two Gallons tips above 50% coolant but 70% is allowed by most Brands & better to have a little more coolant that Anything < 50/50 mix. Isn't just freeze/boil protection but additives to lube W-pump seal, anti-rust, etc will also be weak. Worse, if you have Dexcool & some other "advance" coolant products will cause more problems if gets weak or polluted for any reason like many newer GM vehicles. Web search "dexcool gel problem." Cliff Pennock FEB 08, 05:19 AM quote Originally posted by 1985 Fiero GT: I think what is trying to be conveyed about number 4 is that if you start the car with the cap off, it will spray, if you start the car with the cap on, then remove it with engine running, it will not spray. Not my experience... If I remove the cap with the engine running, it will still spray...