So I pulled the plugs out on the tired 305 and lo and behold there were maaaajor ash deposits not to mention they were oil soaked. The car wouldn't stay running because they were so bad. Had to replace the ignition rotor as well. Strangely the wires are still in good shape. What would cause all that oil blow by? Valve stem seals? This thing needs some TLC but I definately think its worth saving. Just neglect.

 

seals, or valve cover gaskets that leak and the oil runs down on the outside as well.

 

Ash could be running rich, burning oil, weak ignition or wrong plugs.

How did you check the wires? Just because they look ok doesn't mean they are. Check the resistance.

How do you know you've got blowby? Is it smoking all the time or only on startup? Blowby is not a term for buring oil. It means that compression is getting past the rings. Do a leakdown test to see if the rings are still sealing. If you're losing compression past the rings that would account for any external leaks you've got because pressure will build in the crankcase and push oil past the gaskets.

 

yea compression test is next on my list, if the rings aren't sealing Im gonna recommend her pulling the engine and trans, getting a rebuild, and junking the body. I dont think the body is worth saving if the engine needs new rings. Too much work, IMO. It does need new valve cover gaskets too thats a given. Also a front seal. The external leaks aren't a concern to me. Neither is too big of a job.

When the car wouldn't start before I changed the plugs, upon cranking black ash was coming out of the tail pipe. Made me think the cat was fried, but once I changed the plugs it started fine and ran pretty clean. Except the white smoke in sub zero temps, lol.

What would cause it to run so rich? Choke stuck open or does the carb need an overhaul. I think the choke is bad because I pulled off the vacuum hose for the choke and the diaphragm didn't seem to hold vacuum. In this case what exactly needs to be replaced? The car does NOT like starting in the cold. When it was -10 I discharged the battery trying to start it. Once I got a jump it started but i had to keep it alive with the throttle until it warmed up some.

Thanks for the help guys!

 

Compression won't tell you everything. You'll need to do a leakdown to see where the compression is going. Could be the rings, bent valves, guides or valve seals.

 

I always thought they were the same. Thanks, I'm sem-new to engine diagnosing. So a compression test shows cylinder pressure, leakdown testing shows cylinder pressure loss, right?

 

You got it. Make sure to do the test with the engine warm and keep the temperature constant through the whole test to get accurate results.