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'07 Type S
140k mi.
Purchased with 130k and currently use BG Full Synthetic.
Preparing for a valve adjustment in morning and pulled the valve covers. Quite surprised to see the front bank with substantially more carbon and discoloration. Normal? Potential cause?
Thank you in advance peeps !!
Last edited by Millwoodva; Sep 20, 2024 at 07:21 PM.
My valve covers didn't look as bad as yours but the color difference on the valvetrain looks almost exactly the same, and i change my oil every 3k miles with castrol full synthetic
Typical on dbw j series, front head has a pcv in the valve cover, the rear head has a large breather. Older j series were the opposite. Should change the PCV & maybe check the egr passages for buildup.
food for thought, the front valve cover face abuse more than the back. especially in hot weather state, the heat from the front cat goes up then either radiator fan and/or a/c fan blowing all of that hot air into the front valve cover. also the proximity of the front bank shit to another heat source and that is the radiator, meanwhile the rear bank doesn't experience as such extreme temp swing.
It's because the PCV valve draws all crankcase blowby gasses into the front head where they cook the oil into the surfaces. Meanwhile the rear head is getting fresh air as mentioned by the other user.
