Hello All-

After adjusting the valves to spec (1977 300d non-turbo) and doing a compression test, I received the following results:

1- 260
2- 260
3- zero
4- zero
5- 220

I was pretty disappointed in the results. I did this compression test cold, as the car would not start. The last time the car ran was about 3 months ago. During this time, I experienced a significant decrease in power. The next day, the glow plugs did not work, and I have been diagnosing problems since. I decided that the go/no go decision on fixing this car would be the results of the compression test. I know people usually do this test with a warm engine, but I did not have the luxury.

I am thinking that it may be:
1. Rings going bad, and thus losing compression.
2. Stuck Valves.
3. Bad head gasket (I would like to put my money on this, as the performance issue was more abrupt, and there are two cylinders affected, and not just one.

Is there anything else that may have caused this?

To fixing any one of these problems, I am obligated to pull the head off correct?

BTW, I used a compression tester from Harbor Freight. This was done through the injector holes, with head shields removed. (Injectors, BTW, overall, are covered with carbon, however the cleanest of the five were from the cylinders with zero compression...) I would love any input you might have.