Its about one of my other cars, a Plymouth Neon.

About a month ago the engine overheated, found a bad radiator cap, replaced the cap, thermostat, and refilled with coolant. No leaks so I thought the prob was fixed.

However, I noticed that after shutting off the engine air bubbles would blow through the reservoir bottle.

One month later, car overheats again, sure enough the radiator is bone dry. This time I get an SES code 43 (cylinder misfire). Furthermore, I have always had a noticeable oil leak (at least 2 years). However the oil has never shown signs of coolant mixed with it and the exhaust smoke looks normal.

I'm going to check some other things first, but could this mean a bad head gasket or worse?

 

most likely a bad head gasket, yeah. possibly a cracked head depending on how hot it got, but i'd be betting on at least a bad gasket.

 

Aluminum heads aren't nearly as durable nor forgiving as cast iron. Aluminum castings generally aren't quite as stable as iron, just because of the material. Bore a couple of holes down the long axis to weaken it more, then slide a cam through the holes to add more stress to an already marginal part, and you have a recipe for warped aluminum castings. Push the little engine hard, then abuse it just a little with low coolant or lack of lubrication, and it will probably fail. Most of them do under those conditions.

On the bright side, I'll bet you can find any number of reman head assemblies at your local parts house. They usually stock them because of the good market created by the fairly common failures, such as yours. While you're there, ask how many reman SBC heads they have. You won't wonder why I'm not a big fan of small engines that are forced to be pushed hard just to move the car. Expect about six Franklins to get the replacement head, and don't forget the gaskets and a new timing belt.

 

Those engines are prone to head gasket problems. If youre lucky, thats all it will be. Make sure the cam turns ok without binding when you have it apart, thats usually where the real problem comes in on a warped aluminum head with a cam stuck on top.

 

Whats a sure fire way to diagnose a bad head gasket.

Compression test?