I gotta flush mine too. The previous owner didnt do $#!^ taking care of the car so now the coolant is a rusty nasty color and it's really low..

 

you can use simple pool ph papers to test if theres hydrocarbons on the coolant... coolant is pretty basic around 10ph anything less than 7 would be exhaust gasses getting into the coolant and making it more acidic

 

Cool thanks. I was hoping to get a few miles out this car while I save for a crate engine.

 

Well, I took at break from this thing for a few days. I replaced the coolant sensor and 1 of the 3 fan relays (thats all that was in stock). I know have heat in the car but the fans aren't kicking on when there supposed to. I moved the 1 relay around to no avail could get 2 more but what are the odds all 3 relays are bad. I hot wired the fan and motors work good, I'm thinking of hot wiring and riding around to see if it over heats. Does the air pump effect cooling on these vehicles? It appears it's missing parts and I gotta couple loose connectors I traced to the air pump relay. I'm trying to do a diagram search to see what I'm missing.

 

Are you sure about this? One of the side effects of coolant sitting still and aging is it give off an acid. If the coolant sits in a non-running car for 2-3 years it can eat thru a aluminum intake. I have seen several 307 Olds motor with intakes eaten right thur. One I remember very clearly was a 87 Olds 442 with 8,000 miles on it. It was still under GM warranty. They got a whole new motor but the guy was pissed because his car was no longer numbers matching.