In my previous post, I was questioning my own sanity for considering the purchase of 2 undrivable (mechanical problems) but otherwise nice, rust-free cars: a 1989 740 and a 1987 240, each with approx 160,000 miles. The 240 doesn't start (reason unknown) and the 740 has a bad transmission. I only really wanted to buy the 740 but the owner wasn't going to sell them separately. So I paid $1000 for both and had them towed home.

I plan on posting regular updates to this board, as I'm sure I'll need lots of help on the way to getting these cars road-worthy again. I don't need either of these cars for primary transportation, so I'll be taking my time during this process.

So tonight I do a compression test on each car. BTW, my compression tests are done with all 4 spark plugs removed, engine cold and foot off the gas (don't know if this is "proper" or not). The 740 measures 175 PSI in all 4. Upon closer inspection, I notice that the 740's block is painted black! It's a rebuild, and there is absolutely no crud under the oil filler cap or anywhere on the cam (rebuild must have been recent). So I think the 740's motor is in good shape.

But the 240 is another story. It's compression is 170, 170, 155, and 90 (from front to back). I squirt oil in the #4 spark plug hole and it goes up to 155. So my question is, how can there be such a disparity between compression in each cylinder? Does the squirt of oil absolutely confirm bad compression rings, or could there be something else wrong?

Thanks!