M157 Crankcase Breather / PVC Replacement
Last edited by FireBall; Apr 4, 2025 at 03:09 PM.
Start with the immediate issue(s) at hand and simply replace everything in your line of sight and follow the yellow brick road until the problems are gone. You will ultimately end up replacing everything plastic underhood.
Last edited by chassis; Apr 4, 2025 at 04:13 PM.




> How to deal with that ??
- you can reduce crankcase pressure...
- replace PCV + plugged up duscharge hose Line
- decrease pistons blowby pressure leak
- replace only few hardened oil seals
- fix known leaks (CPS) & issues (stuck rings)
filter CAP + cooler + Tstat
Nos 170 +180
Nos 60 + 50
No 90 (+ O-rings)
The more you seal crankcase pressure by replacing new seals, the more it's going to stress your rear main seal and timing cover seals too. Either may become a terminal condition.
So reducing the source of blow-by pressure should be a top priority, not the dirty leaks.
Last edited by CaliBenzDriver; Apr 4, 2025 at 04:59 PM.





High blow-by leaks evolves with colaterals:
- misfire faults
- engine vivrations
- reduced output
- spongy throttle
- poor shifts
- extreme heat
- oil consumption
- carbon'ed valves
- Contaminated Lambda
- VacPmp check-valve
- CPS: "$10k-oil-in-harness!"
- .....
Stick with the root-cause else repairs too expensive!
Last edited by CaliBenzDriver; Apr 4, 2025 at 07:10 PM.





