would valves cause this?

[jasons_98gt]

long story short, i got everything in the car and it running finally. everything seemed good, all except white smoke!!!! i figured maybe from the car sitting so long. well it didnt stop.

so i pumped the cooling system with 16lbs of pressure and it would not hold at all. so i pulled the spark plugs, 5,6,7 were full of anitfreeze. i figured head gasket, so i pulled the heads, the head gaskets looked fine, and checked for warpage. Nothing!

so i took the heads to a machine shop to have pressure tested, well the guy called and said they were perfectly flat and didnt need milled. but when he pumped air into the heads he found that the valves in 5 6 7 were blowing air past. he said thats where my antifreeze was coming from?

does that sound right to you guys at all? who would of thought that a motor with 72 thousand miles would need a valve job!

anyways, since hes doing a 3 angle valve job i didnt stop there, im going to have them ported and polished, as well as bigger valves put in...

[somethingclever]

leaking valve seats do not cause a coolant leak into the combustion chamber

[Warrior1670]

Seems quite shady...last I heard, valves move air, fuel and exhaust, not coolant. Did you take your head to Shadytree Mechanic?

[jasons_98gt]

yeah thats what i figured...no i took em to a place in washington that i have dealt with before..and trust the shop. but like i said and he said, the heads were perfectly flat, im thinking even though the gasket looked good it was leaking... as the heads arent leaking internally. thats why i had them pressure checked.

[mgtf289]

SMO has a Delta Pressure Tester ( very good machine ), they also have a Serdi to do a much better than a 3 angle valve job ( old school ) Todays jobs would be 4 angle intake & radius exhaust. Bod valve seats will not leak coolant, but an internal crack at valve guides etc will leak into the valve area.

[jasons_98gt]

what would cause bad valve seats? just from the heat of the combustion chambers against the aluminum or?...

[mgtf289]

Jason, A lot of things cause bad seats. Heat, poor fuel, cam timing, carbon, but none of those cause coolant leaks.

[SAC81]

Still running the plastic intake manifold? It may be cracked and leaking- the intake valves on 5,6,7 may have been open when you pressure tested it, letting anti-freeze in.