Cracked head or failed gasket?
01-27-2017, 06:02 PM
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Car: 86 trans am
Engine: 305
Transmission: 700r4
Cracked head or failed gasket?
I have an 86 trans am with a 305. When I bought it it had a slow exhaust into coolant leak (a half hour of hard summer driving before it spewed into the overflow). I never had found any coolant in the oil. When I removed the head I noticed the front 2 passenger cylinders were clean but the steel gasket wasn't broken. 416 castings.
1. Is it super likely that the head is cracked....besides the real cracked head that spent money on a 305 smogger?
2. Is there any way to test that doesn't involve sending the head to a shop?
1. Is it super likely that the head is cracked....besides the real cracked head that spent money on a 305 smogger?
2. Is there any way to test that doesn't involve sending the head to a shop?
01-27-2017, 06:44 PM
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Re: Cracked head or failed gasket?
A cracked head is possible; not particularly likely though.
No way I know of to check that once it's tore down other than have a shop pressure-check it; short of, rigging up a good pressure-test setup yerself. All you'd need is a big flat plate with some GOOD O-rings to seal around the chambers and some holes to bolt it to the head; and acoupla smaller plates to cover water outlet ports, with one of em with a Schrader valve in it to pressurize with. Not really rocket surgery or brain science or anything, just, takes some stuff most people won't have laying around.
If it was me, I'd clean all that stuff up real good, get a set of GOOD composition head gaskets (HS-7733-PTx), a GOOD radiator cap which is likely all that was wrong with it before it was taken apart, and put it all back together. Maybe get the valves ground and replace the valve springs while I was at it.
No way I know of to check that once it's tore down other than have a shop pressure-check it; short of, rigging up a good pressure-test setup yerself. All you'd need is a big flat plate with some GOOD O-rings to seal around the chambers and some holes to bolt it to the head; and acoupla smaller plates to cover water outlet ports, with one of em with a Schrader valve in it to pressurize with. Not really rocket surgery or brain science or anything, just, takes some stuff most people won't have laying around.
If it was me, I'd clean all that stuff up real good, get a set of GOOD composition head gaskets (HS-7733-PTx), a GOOD radiator cap which is likely all that was wrong with it before it was taken apart, and put it all back together. Maybe get the valves ground and replace the valve springs while I was at it.
