After breaking a timing belt due to a bad water pump I couldn't start the engine. I performed a compression test and had almost nothing on 5 out of 6 holes. Knowing I had installed the belt correctly I removed all timing components and began to test compression by rotating cam lobes upward and testing every hole. Same thing. almost no compression. So at this point I'm pretty sure I bent the valves. So after getting over about 3 weeks of bad attitude I pulled the heads and what did I find? nothing! All valves are straight as can be. I had the valves checked at the machine shop and everything is good. Anybody have any ideas as to why I lost compression? My thoughts are I let the engine sit too long and the valve carbon may have solidified. I know the air was escaping past the valves because I poured alcohol down the head at the intake valves and I could blow through the sparkplug hole and watch lots of bubbles come out of the valves.

 

You didn't do the compression check properly. Even leaking valves would have given you something.

Sorry,

Bob

 

Something sounds strange. Can you confirm whether you did a leak down test or a compression test?