combustion gas in coolant

[bwgarrett56]

Without going into a long story about this engine I had combustion gasses in my cooling system and loosing a fair amount of coolant. Pulled head, #1 cyl and piston scored.
Honed cyl, replaced piston and rings, replaced main and rod bearings, replaced head (small cracks at injector bore)
After all was done, it is doing the exact same thing. Exhaust gas into cooling system (bubbles in radiator), loosing a fair amount of coolant.
I don't know what to think or do at this point. What did I miss ??

[dazedandconfused]

The deck of the block could be warped along with the head. You could also have a crack you didnt notice.

[bwgarrett56]

The head that I installed was decked and checked. Since I did a in frame repair job, The block surface was pretty much ignored. Just ran a straight across it, looked ok. Any chance of the block problem comming from anywhere else ?? cylinder wall ??

[dazedandconfused]

Yeah it could be a hairline crack in the block.

[142autox]

Are losing coolant externally? What does the exhaust look/smell like and how does it run?

[bwgarrett56]

Are losing coolant externally? What does the exhaust look/smell like and how does it run?

Nothing external, the exhaust doesn't smell like a/f and the engine runs great.

[PToombs]

Put a radiator pressure tester on the radiator, then start the truck. Watch the gauge on the tester, if it goes right up, you have a big problem. You didn't really say if there are lots of bubbles or just a few. If the pressure doesn't go up, I'd look for a non pressurized leak to an oil passage, external, or maybe the heater.
Might be a good idea to have an oil sample tested too. That will also tell you if the AF is ending up in the base.

[bwgarrett56]

Put a radiator pressure tester on the radiator, then start the truck. Watch the gauge on the tester, if it goes right up, you have a big problem. You didn't really say if there are lots of bubbles or just a few. If the pressure doesn't go up, I'd look for a non pressurized leak to an oil passage, external, or maybe the heater.
Might be a good idea to have an oil sample tested too. That will also tell you if the AF is ending up in the base.

That's funny you asked this. Today I got my hands on a pressure tester and pumped it up on a cold engine. No problem, held the pressure. Then I took off on a 20 mile test drive, got home released the pressure from the radiator cap, screwed on the tester, pumped it up. Again no problems, held the pressure fine. Then I started the engine, again the gauge stayed the same, No spikes or anything . Just steady pressure
So ya ask, what is going on here.
This is what I am thinking now. I might of jumped the gun on the combustion in the coolant. Because it was doing the same thing when I was having the big problem at the begining. I got real nervous when I saw the reservior loosing all of that coolant, and the blowby looked kinda steamy like it did before. I think that the bubbles that I was seeing was some of the trapped air escaping from the cooling system refill.
I marked the reservior level when I started the engine and did my little test drive and yes it's going a little below that mark here tonight. I wonder if it will keep on drawing it out like it did after the initial cooing system fill.
Anyway thats whats going on.

[PToombs]

After 4 or 5 engine run cycles it should be all done purging air and sucking in AF to make it up. So after a week of driving, when you check it cold it shouldn't change much.
Sounds like it may be ok, just a case of nerves. Been there myself, not a biggie!

[bwgarrett56]

After 4 or 5 engine run cycles it should be all done purging air and sucking in AF to make it up. So after a week of driving, when you check it cold it shouldn't change much.
Sounds like it may be ok, just a case of nerves. Been there myself, not a biggie!

Yea,
I will run it a little this week and see what happens.
Hope for the best
Thank you for your help !!