Originally Posted by barry123400

Yes it could. I do not know your capabilities. Injecting air into cylinders sometimes indicates where problems are. You could fill the cooling system run the engine and look for bubbles in the coolant.

Bubbles are headgasket or cracked head usually. All I know is you have to address the serious issue first. Untill then playing with the lesser items is just wasted effort. You have indications of a real underlying problem.

The last owner indicated it to you as well. If you do pull the head it must be checked for flatness if it seems to be a headgasket and cracks in the head are not found.

The new rad might be an indication of a headgasket leaking or crack causing the car to run too warm for quite awhile before it got too serious to drive. The owner possibly thought it was just an old tired rad not cooling properly. So it was replaced. One way or another at present it really looks like the head will have to come off. Doing a compression check first is preffereable. I expect there will be a piston top in that engine well washed off anyways.

Pull that number one injector and roll the engine over as well if you have not yet. You want to localise the majority of the issue. Once an engine is apart is usually harder to accomplish. At least for a person like me.