boiling after head job

I have a 95 3.9, just had head gas replaced and now its boiling over in the overflow tank. done compression test on each cyl. all are the same. it does this after bought 30 min of driving. oh yea 138,000 on the clock. is there something I am missing?

yes

what caused the HGF?


If that wasnt fixed then thats what is causing it to overheat again.

air locks maybe. Either that or a failure on the water pump,or thermostat,blocked rad

I noticed coolant leaking from the front of the heads on both side just where they meet the block. that is why the head gas was replaced. it has never ran hot and still doesn't. there was no gushing sounds in the system so I can only assume it was bleed properly.

new water pump while it was down "just to be safe"

have you flushed the cooling system. Also do you get any pressure in the head tank straight away or does it pressure slowly

I have not flushed it, and it take bought 30 min "of driving" for this to happen, it can sit at idle for ever and doesn't boil.

cross your fingers block not cracked behind liner passenger side if non serpentine belt,but as said check rad hot all over core

heads scimed??

heads went to machine shop and tested, and milled. top of rad will cook a steak, as for the bottom I dont know.

serp belt, and like I said it has never ran hot.

as for flushing should I use a flush detergent or plain water.

i would get recored or replaced if hot at top and not hot going down core evenly

thank you all

i've never used a flushing agent, just removed the stat, and run a hose pipe through the coolant bottle with the top or bottom hose removed, until the water runs clear. However if your not getting even heat on the rad then as said above replace it or get it repaired. good luck thou matey

since my last post I have ran truck till it came up to normal temp shut it off and felt the rad all over from top to bottom and it was hot on top and the further down the cooler it got. with that as some of you stated it must be clogged, now my question is do I try to get it fixed or just buy a new one?

try using central heating flush on the radiator if it works its a cheap repair.

update it was a clogged radiator, bought 90% so says the rad shop. $60.00 and a new jug of coolant and all is well. I now assume this was the reason for the leaky heads to start wif. Many thanks to everyone. Have a beer on me.