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New Member
- Joined
- Aug 3, 2018
- Messages
- 9
- Reaction score
- 0
- Points
- 1
- Location
- UT
- Vehicle Year
- 1993
- Make / Model
- Ford
- Engine Size
- 4.0 V6
- Transmission
- Automatic
'93 4.0 V6
As the title suggests, I re-ringed the cylinders, replaced the head gasket, did the valve seals, and lapped the valves to the head after low compression in cylinder #6. After putting it all back together, the compression in 6 went back up, but the compression in another cylinder dropped to nil. I also lost vacuum. After trying to find the leak, I determined the vacuum leak must be coming from an intake valve not closing all the way. I opened the truck back up, monkeyed around some more, and now she has vacuum, but not a lot of power. Compression is pretty garbage in a few cylinders. I can mess around under the hood and get the compression to go up with shims on top of the valves, but then it loses power (maybe not breathing out well enough?). If I had to guess, I would think that this is a case of the lifters not doing what they are supposed to. In some cylinders the push rod is in constant contact with the rocker arm (even when the valve is fully closed). In other instances there is a noticeable gap when the valve is fully closed. In these cases I can wiggle the pushrod a little bit at BDC or TDC for that cylinder, respective to when the valve is fully closed. There is also lifter noise now when there wasn't before I took the heads off for the top end work. This is the first motor with lifters I have done, is there something I did wrong?
As the title suggests, I re-ringed the cylinders, replaced the head gasket, did the valve seals, and lapped the valves to the head after low compression in cylinder #6. After putting it all back together, the compression in 6 went back up, but the compression in another cylinder dropped to nil. I also lost vacuum. After trying to find the leak, I determined the vacuum leak must be coming from an intake valve not closing all the way. I opened the truck back up, monkeyed around some more, and now she has vacuum, but not a lot of power. Compression is pretty garbage in a few cylinders. I can mess around under the hood and get the compression to go up with shims on top of the valves, but then it loses power (maybe not breathing out well enough?). If I had to guess, I would think that this is a case of the lifters not doing what they are supposed to. In some cylinders the push rod is in constant contact with the rocker arm (even when the valve is fully closed). In other instances there is a noticeable gap when the valve is fully closed. In these cases I can wiggle the pushrod a little bit at BDC or TDC for that cylinder, respective to when the valve is fully closed. There is also lifter noise now when there wasn't before I took the heads off for the top end work. This is the first motor with lifters I have done, is there something I did wrong?
