my truck is a 89 silverado 350 with a fresh rebuild.

hey everyone im having a problem with what i think is my radiator but im not 100% sure if thats where my problem really is.

so i went and rented a coolant pressure tester from autozone the other day and hooked it up to my radiator and pumped it up to 15psi, i crimped off the overflow line so it wouldn't leak out the overflow. now i got it to 15psi and it would take about 30 mins for it to all bleed out, im not sure where it is leaking though. i sprayed so soapy water all over the radiator to see if it was leaking but it couldn't find any spots bubbling.

now about a year ago i blew a freeze plug on the drivers side of the block and replaced head gaskets to be safe.

im not worried that when i blew the freeze plug that it wasn't the only damage done. im worried that i might have cracked a head when this all happened.

so basically how likely is it that i would have cracked a head?

or what els do you think could be the problem?

 

I doubt it. What caused the plug to blow? If it where cracked, and you are thinking the pressure to bleed off, that would mean coolent in the combustion chamber(s). Even pinching off the overflow that is a pretty "open" system. Thirty minutes to bleed off, to me isn't bad. However you can run this test a few times, and pull plugs to see if there is anything in the cylinders. The pressure tester itself could be the bleed off problem.

 

thanks kevin, well the plug blew in the middle of winter from what i beleave was caused by to much water in the antifreeze/water mix.

ok well tomorrow i will try again with the pressure tester a couple times and pull the plugs to see if there is any coolant in the cylinders or on the plugs, ill repost tomorrow with an update.

ive been working myself up for a little while the it was a cracked head, it was the first engine i rebuilt.

 

ok so i pressure tested it some more and im not getting coolant in the cylinders but my coolant is getting into the oil pan somewhere. i pulled the radiator to see if the oil cooler lines were busted inside but the radiator is as solid as ever no bubble under water with pressure.

my next guess would be intake gasket. but how would i figure that out?

when i rebuilt the engine i got some new bolts for the intake, some grade 8's but they feel like they stretch quite a bit when they get torqued down.

edit: i pulled all the plugs to check for coolant on them under pressure but they were dry as ever.