No engine Compression?
 

Hello,

What would cause an engine to have virtually no compression; 1980 300SD, car can do a maximum of 10mph, head gasket has been replaced.

Thank you!
Alex

Edit: TO all those who have replied, I thank you for the input, turned out to be a broken part: follow this thread for more info: http://www.peachparts.com/shopforum/diesel-discussion/357371-parts-identification.html#post3358396

Undertightened head? Screwed-up valves?

If it had "virtually no compression" it wouldn't start. By the way, what is the compression on each cylinder?

I'd be looking at throttle linkage first.

Are the valves waaaaay too tight?

If the head was removed and it had reasonable power before (did it?) check:
1. Valve timing,
2. Valve clearance,
3. Injection pump timing,
4. Air intake restrictions (e.g., a rag getting sucked in the air cleaner),
5. Linkages e.g., when depressing the accelerator does the linkage at the pump move accordingly, and
5. Vacuum hoses.
Good luck!

Yeah, "no compression" would mean its sitting quietly and not running. :)

If it runs (does it idle normally?) but is slow, I would suspect throttle linkage adjustments, fuel restrictions....etc Does it rev freely if you move the linkage under the hood?

If the problem is only since the head job the most likely candidate is the injection pump is out of the proper phase. With both intake and exhaust cam lobes on the first cylinder pointing generally upward. The damper mark where it should be.

The number one fuel element of the injection pump should drip test properly. They can run poorly with the pump way off and usually harder to start as well mind the poor performance.

If that is not the issue. Maybe someone left a rag in the system for example when putting it back together.

What are the compression readings for all cylinders? If you have not done an actual compression test, you are guessing.

X2 ^^

Help us help you by posting your compression numbers.