97 4.0L sohc no compression

[jmayo]

just aquired a 97 explorer witha 4.0 sohc with no compression is this gonna need timeg chains and valves?

 

[fordnut71]

if the chains have broken an the valves are open your not going to have compression. or it could be head gaskets.
is all the cyls have a lost of compression?

 

[zogg]

How do you know it has no compression???

Did you do a compression check yourself? If so, did you do it dry and also wet?? That would tell you if the valves or rings are shot....

 

[jmayo]

no i did not do a compression test it spins over as if you pulled all the plugs out and cranked it.
John

 

[fordnut71]

well you need to check to see if its the lack of compression you have. it could be something else thats cause a no start.

 

[jmayo]

i will check but it is extremely obvious that there is no compression you know how easy an engine with no plugs turns over well thats this one!!!

 

[2000StreetRod]

possible causes

There are lots of reasons for low compression resulting in higher than normal rpm when cranking. Holes in pistons from detonation, burned exhaust valves, worn piston rings, blown head gaskets, stuck open valves are some of them. As zogg suggested, I would perform a dry and wet compression check. Remember to do it with wide open throttle. I would also disable the ignition, remove the valve covers and crank the engine and observe what happens.