| Re: replacing driver's side head on a 455 [message #362734 is a reply to message #362723] |
Mon, 08 March 2021 17:51   |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma:
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Senior Member |
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If you throw out this “warped head” theory and go with just a bad head gasket you have a win. Now sell the headers (proven no gains) and bolt on 2 manifolds and done.
I had a similar “brain logic diagnosis” just a couple weeks ago. Follow me here. My XJ with 300K miles was weekly low on coolant in the overflow. Kept adding 50/50. It would also start in the morning with 1 dead cylinder more and more often. Reving it would clear it and it would not miss all day at any speed. Finally it started with the miss and would not clear. Cyl 2 missfire. Pulled plug expecting the worst. Head gasket. Hoped for carbon in gap, but no, LOOKED fine. Got the METER and Ohmed center to side. Had some value not open circuit. Also metered center to tip and that was 100k too high. So the plug was arcing internally and not visibly bad. 6 new correct plugs and under $20.
Aa for coolant loss, removed cap (fairly new) and cleaned plastic neck with cloth and rinsed cap off. Put a light film of grease under the cap hold down tabs. This earless type cap was now way easier to palm and turn. Turned back and forth several times to get a better seal on plastic neck. No more high speed coolant loss past outer gasket.
Moto is everything pointed to head gasket and it was totally two other issues and an easy fix. Don’t throw out baby with bath water.
John Lebetski
Woodstock, IL
77 Eleganza II
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