Tore engine apart kinda baffled???

[black95gts5.0]

Alright I bought a complete 5.0 engine out of a 95 mustang that was burning oil and pulled out at 107.000 kms or like 64,000miles for $150. It was supposed to have low compression on cyl #8 and I pulled the heads off last night kinda scared at what I would find, the cyl walls all look perfect but I havent pulled the pan and taken the piston out yet. It looks like the whole engine was burning really rich or something, lots of carbon buildup. I will pull the pan and pistons tonight and see what I can find but any other suggestions to what the problem could be???

 

[1105]

have you checked the valves to see if they are burnt or have carbon built up on them? Put some gas in the intake and exhaust port of the head and see if its leaking out from between the valve and seat if you're not sure. May not be the burning oil problem, but it could cause the low compression.

 

[WhiteDevil]

If the heads are old and the valve seals are ****ty that could cause buring oil. Mine used to go through a quart or more ever 3k miles, with the new head and new valve seals that problem went away. I check the valve seals on my E7s and they were like plastic.

 

[skylovia]

dont forget, carbon build-up would cause HIGH compression. The carbon would take up space in the cylinder and artificially raise compression.

 

[1105]

not if the carbon is holding the valve open a little bit. We had to do a valve job on a jeep that was like that.

 

[mo_dingo]

Have the heads checked out by a machine shop. If they find a problem with them, then you know that was your problem, and you shouldn't need to disassemble the rotating assembly.
Scott

 

[black95gts5.0]

I took the #8 + #4 pistons out and took them to a machine shop and he said that there is nothing wrong with the rings, but there is some copper showing on the bearings and I took two of the crank caps off and they were also showing very slightly a bit of copper. So I will re-bearing the rod, mains and the cam when I can get my hands on a used e, f-303 or the like for a good price. The shop figured that the # 8 has a bad stem seal and is letting oil in that way. I am going to GT 40 Explorer heads anyway so I will not worry about the E7"s. Will keep posted on the developments.

 

[ROLLIN5.0]

For future reference. You could have just filled each cylinder with oil (after you removed the heads), and let it sit for a couple days. If #8 has less oil left than the others, the ring is worn. If it didn't, you had a problem with valves. You might as well rebuild the whole thing while it's out though.
Brandon