4.0 with burnt valves
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Joined: Oct 2000
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4.0 with burnt valves
93 4.0 130k miles. It quit on me on a run from Pheonix to San Diego this June. I had it towed home and just recently opened it up.
Water in cylinders on both sides. Obviously head gasket was blown.
Also, both middle cylinder(2&5)exhaust valves were burnt through in an oblong pattern right up to the stem.
I also noticed that although the head and the block have a number of water passages in them that would match up, the gasket severly restricts the flow around the middle cylinders. Has anyone had this same problem with both exhaust valves being burnt in almost an identical pattern?
Bruce
Water in cylinders on both sides. Obviously head gasket was blown.
Also, both middle cylinder(2&5)exhaust valves were burnt through in an oblong pattern right up to the stem.
I also noticed that although the head and the block have a number of water passages in them that would match up, the gasket severly restricts the flow around the middle cylinders. Has anyone had this same problem with both exhaust valves being burnt in almost an identical pattern?
Bruce
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Joined: Apr 2000
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From: PNW
4.0 with burnt valves
I just replaced the heads on my '95 4.0 (built 11/94). #6 cylinder exhaust valve was recessed quite a bit into the head and #5 exhaust was recessed too, but not as much as #6. #5 showed only a little loss of compression compared to the other good cylinders but # 6 was off by 25%. This was with only about 78K on the motor. Also, when I had it apart, I noticed that the casting dates were different on the two heads ('94 and '96) so sometime before I bought it, the other head was replaced (prior to 56K). I didn't notice anything peculiar about #2 but then there wasn't that much time on it. I also noticed that the head gasket holes were smaller than the water passages in either the head or the block but didn't think much of it since my engine has never had any problems keeping cool.
