Phil99vette

iTrader: (11)

We installed a H & C package a month or so ago with a set of used heads. When we initally started the car we noticed some coolant smell/smoke coming from the passenger side exhaust. Well a month or so goes by and the problem gets progressively worse to the point where coolant is puddling in the mufflers. The owner pulled the head off and all looks normal with the shortblock but the exhaust runner has signs of dexcool and a slight "hairline" mark. Has anyone seen a head crack letting coolant escape in the exhaust runner?
Phil

LOnSLO

iTrader: (15)

I've seen the material between the exhaust and intake runners split when new seats weren't installed properly. Is that where your crack is?

Ferocity02

iTrader: (60)

Blown head gasket?

Phil99vette

iTrader: (11)

I initally thought it was a blown head gasket but its a fresh cometic with copper spray and we've never had problems. The plug and piston look normal.
Phil

ArKay99

iTrader: (1)

A while ago I sold a set of used, but untouched LS6 heads to a porter. I cleaned them up before I sent them to him and he asked me if I saw any 'pinholes'. I asked what they were and he explained they were little holes that are sometimes in the casting left by the sand and any bubbles in the molten metal. He explained that sometimes the pinholes are close to the surface and when the heads are ported the pinholes can open a small hole to the water jacket. He told me it's happened on more than one set of heads he worked on. I guess at that point they have to be welded. Could this be the problem?

DaddySS

Of course I'm guessing but if it were head gasket, more often than not you'd oil in water or water in oil. The fact that you only see the system in the exhaust port and exhaust would lead me to conclude that it is the head and probably right where you say. I would put a new set of heads on before any further damage occurred if it were mine.

Beast96Z

iTrader: (21)

Pressure test the port/ports in question. That will give you a deffinate answer. If they hold pressure, it's probablly the gasket.

eallanboggs

iTrader: (1)

I've done sand castings and this pinhole theory doesn't hold water. The sand only touches the surface of the material being cast. If such a defect happened during casting it would be discovered when the casting halves were seperated. In order for a pinhole to find its' way all the way from the head surface to the water jacket is less likely than winning the Powerball.

n20stroker

iTrader: (11)

Dont know if this will help, but today at work a cust came in staying he had coolant on top of his intake. It was a 2004 chevy truck C body. I pressure tested the cooling system, in three different spots coolant was coming through the intake. You could se little bubbles coming to the top. The intake was defective bad cast. So the same could happen to a cast head.

GuitsBoy

iTrader: (4)

Ill agree here. No way a pinhole would go clear through. Look for cracks, as that has been known to heppen. Welding would be your best bet.

WKMCD

iTrader: (2)

This is my C5. It wasn't passing a little coolant. It was actually pumping it enough that it was leaking 2 quarts or so of coolant from the mufflers. No coolant in the oil. The car ran OK. I pulled the head after identifying things from a slightly discolored spark plug. It did not look fouled. The header pipe on the number 2 cylinder was wet and all the others were dry. I had the head checked it they couldn't find any problem. I'm still thinking they missed a crack in the exhaust port that opened up with a little heat. There is no way that this much coolant could pass through the combustion chamber without fouling the plug. Anyways, Phil's checking it out and I've got a set of PRC 2.5 hand finished heads on the way.

Phil will get it right I'm sure. BTW, the car ran great. Thanks, Phil.

Phil'sC5vette

iTrader: (4)

I feel for you bro.

I sold the AFRs Tuesday. WE could have thrown them on just to check if it was the heads

01ArcticSS

iTrader: (1)

I had coolant POURING out of an 84 Z28 (yeah, that LOVELY crossfire fuel injection).

I had cracked the original manifold and ordered a new one, and it was the new one causing the problem - there was no "wall" between the aiir passage and the coolant passage, so all the coolant I poured in was running straight through a cylinder and out the tailpipe.

ANOTHER new intake manifold and all was good.

WKMCD

iTrader: (2)

Similar symptoms but the C5 uses a dry intake. Same with the LS6 and LSX intake. We can rule that out.

Thanks