Ford420
Registered User
Long time since I last posted. Searched and didn't find anything that matched what I'm finding.
The valve covers on my '86 6.9L haven't been off since the engine was rebuilt in 2010. Since then, the truck ran for a while without a turbo, then got the Banks Sidewinder system installed about 30k miles after the rebuild. I'm replacing all the injectors due to high EGTs and noise from several of them. I'm also replacing the injection pump. So, I decided to replace the valve cover gaskets to stop a couple small oil leaks. I took the cover off the driver's side and was disappointed to see deposits (black tar-like sludge) caked on the head, under the #4 and 6 cylinder rockers. The passenger side has none of this though. Is this common to only see buildup on one side? Does it indicate a problem, or is it pretty common?
Driver's side head:
Driver's head, wide shot:
Passenger side (clean, no deposits there!)
For the last several years, the truck only gets driven 2-3 thousand miles a year. It gets annual oil changes, but sometimes is only taken on short drives (not reaching full temp). I run Lucas oil stabilizer (one qt) and Delo 400. I don't have to add any oil between changes. It does run quite cold - think the thermostat is stuck open. Could running cold cause this buildup? I'm installing a new Motorcraft thermostat as part of this project. Crankcase vent is via oil filler neck Banks adapter and hose to the inlet of turbo.
No oil in coolant, no coolant in oil, have not yet completed compression test... re-installing injectors and pump and will get to that.
Should I just throw it back together and run it? Thanks for any advice you have. - Chris
The valve covers on my '86 6.9L haven't been off since the engine was rebuilt in 2010. Since then, the truck ran for a while without a turbo, then got the Banks Sidewinder system installed about 30k miles after the rebuild. I'm replacing all the injectors due to high EGTs and noise from several of them. I'm also replacing the injection pump. So, I decided to replace the valve cover gaskets to stop a couple small oil leaks. I took the cover off the driver's side and was disappointed to see deposits (black tar-like sludge) caked on the head, under the #4 and 6 cylinder rockers. The passenger side has none of this though. Is this common to only see buildup on one side? Does it indicate a problem, or is it pretty common?
Driver's side head:
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Driver's head, wide shot:
You must be registered for see images attach
Passenger side (clean, no deposits there!)
You must be registered for see images attach
For the last several years, the truck only gets driven 2-3 thousand miles a year. It gets annual oil changes, but sometimes is only taken on short drives (not reaching full temp). I run Lucas oil stabilizer (one qt) and Delo 400. I don't have to add any oil between changes. It does run quite cold - think the thermostat is stuck open. Could running cold cause this buildup? I'm installing a new Motorcraft thermostat as part of this project. Crankcase vent is via oil filler neck Banks adapter and hose to the inlet of turbo.
No oil in coolant, no coolant in oil, have not yet completed compression test... re-installing injectors and pump and will get to that.
Should I just throw it back together and run it? Thanks for any advice you have. - Chris