if there's no water in the oil, and if the smoke isn't too bad, could be just an intake leak... check your plugs to see which one it's burning coolant in, and look to see if it's near a coolant passage...
307 bad head gasket
- Thread starter lkovacs
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I second the intake leak possibility. I'd pull the spark plugs and look at them, like fleming442 said.
The good ole valley pan! Nothing like sandwiching steel between iron and aluminum and then running coolant through all three. Great idea.
Dont be afraid to travel if you have the time. I drove from DSM, IA to basically madison, WI in my regal for fenders as well as omaha for my wheels.
i have a truck now but ive hauled engines in cars before. 350 olds drops right in.
i have a truck now but ive hauled engines in cars before. 350 olds drops right in.
The aluminum intake and iron head issue does spring up but that would dump coolant in the oil. Were the 307 steel shim head gaskets from the factory? The few I tore down were Felpro head gaskets. How did the coolant look? I saw nasty coolant eat shim head gaskets, they were starting to dump brown antifreeze into the cylinders on an Olds 350. When these cars were numerous on the road, we never had to pull the 307's down that far. What year is this car? Fixing it depends on compression and oil pressure. Hopefully the gasket is obviously blown as well or heads will also need checked. Other than 3A heads, Olds heads don't usually crack but it does happen. Usually a blown head gasket or cracked head will pressurize the cooling system big time. I blew a Corteco head gasket with Olds 307 5A heads on an Olds 350, did that. My 5.9 Dodge Magnum V8 also did it when a head cracked.
Felpro made the intake gaskets for GM. Probably many others as well. Even their NOS over the counter GM intake gaskets have Felpro stamped on them.
Since the pH of a "clean" ethylene glycol system with Deionized water is normally neutral to a bit acidic, it does seem like a strange marriage of iron/steel/aluminum which seems ripe for galvanic corrosion potential.
I've used Felpro in every Olds engine I've ever rebuilt, and never had an issue with their quality. The GM packaged head gaskets I'm guessing may also be Felpro. I've never yanked the head off of a 307, so I'm not sure what's under there originally. The replacement GM head gaskets are of a sandwiched steel something or other, but I cannot determine any markings at all on the head gaskets themselves. They are blue. Still, suspicions are Felpro manufactured.
GM edition:
Felpro blue stripe edition:
Since the pH of a "clean" ethylene glycol system with Deionized water is normally neutral to a bit acidic, it does seem like a strange marriage of iron/steel/aluminum which seems ripe for galvanic corrosion potential.
I've used Felpro in every Olds engine I've ever rebuilt, and never had an issue with their quality. The GM packaged head gaskets I'm guessing may also be Felpro. I've never yanked the head off of a 307, so I'm not sure what's under there originally. The replacement GM head gaskets are of a sandwiched steel something or other, but I cannot determine any markings at all on the head gaskets themselves. They are blue. Still, suspicions are Felpro manufactured.
GM edition:
Felpro blue stripe edition:
This is a reason to be very careful and alert during disassembly. Keep looking for the coolant path. I'm not an Olds guy, but coolant coming out of the exhaust without pressurizing the cooling system can be a chore to find.
The OP said it's running badly - compression or leakdown check before disassembly. And that is a good time to look closely at the plugs as they are removed - I believe Fleming has already mentioned this once or twice as well.
Is any car "worth" fixing is in the eyes of the owner. Sounds like you are not a wrench turner so it will still cost you no matter which way you go. Is a Cutty with a matching engine worth anything, probably not. Sometimes a divorce is a good thing in the end.
I can't believe the head gasket blew at only 60M, My 83 H/O has 325M with the original, but I've replaced the intake gaskets three times, and replaced timing chain with a Cloyes dbl roller, and my 86 442 had 265M with original head gaskets, but intake gasket replaced twice, as well replaced timing chain with a Cloyes dbl roller. They both were drove hard everyday with only regular oil changes, and good tune up's.
When I was very young the 1st thing in the trash was the instructions, now its the 1st thing I pull out and read. Well actually it was the OEM parts to be replaced by aftermarket stuff. I wish I would have kept those "snowflake" intakes! There is a lot of interesting things on those papers.
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