I just finished replacing the radiator and waterpump in my IROC. Now I am wondering if I should flush out the engine block so the old coolant (3 years old) does not contaminate the new longer life stuff. Is there much coolant in the block itself and if so is there a way to flush it without flushing the whole radiator?



------------------
'87 IROC, 305TPI, 5Sp, , 170K miles, all original except for K&N filter, Vin F

 

Well, if the antifreeze is 3 years old, it wouldnt hurt to be changed, since it becomes acidic over time. I dont know any way to change the antifreeze in the block without changing all of it though.

------------------
1983 Pontiac Firebird SE
LG4-Based Chevy 400
700R4 Tansmission
Modified 4 Barrel Q-Jet Carb
Accel Super Stock 8mm Wires
Edelbrock Pro-Flo Air Cleaner
3.23 Posi Rear
14X7" Cragar SS/T Wheels
35X4 CD/AM/FM Head Unit
100WX2 Amp
2 Pioneer 12" Subs in Custom Box
Third Gen Performance

 

The block itself holds about 1½ gallons. After pulling booth rad hoses, there's about 2 gal total left in everything. The block and radiator are all one closed system so you can't flush one without doing the other.

It's not essential to flush it; but it's a good idea, and now would be the perfect time. There's always a bunch of rust and sediment in the bottom of the water jackets. It is necessary to drain the whole thing including the block. There are 2 drain plugs in the block, one on each side about ½" above the oil pan flange. The pass side one is the knock sensor. I would strongly recommend getting a new one when you disturb it, as they become hyper sensitive if overtorqued or otherwise abused which will probably happen from the removal process.

------------------
"So many Mustangs, so little time..."