Quote:
Originally Posted by Kdawg550GT
I installed this exact system from a previous thread you posted. I have a couple questions. I used your idea of fabricating a spare oil cap and vacuum gauge. Im running roughly -8 psi vacuum at idle. Sure sucks the oil cap down at that reading. Have you found that vacuum increases with higher RPM? Ive also seen a service bulletin from BMW that says vacuum should be at 15 mBar which is .02 psi. This seems to conflict with the -8. Your thoughts?
Second. I found a set of JEGS One-Way Check Valves to replace the clunky PCV's and modified the flapper to just hang there. I like the look and have not burned a drop of oil in over 1k miles. All this concerns me a bit as sometimes I spool up nicely and other times the turbos dont spool at all. Just wondering if youve run into this. BTW turbos were completely rebuilt and when shes on she pummels asphalt.
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Vacuum will actually decrease with rpm as the throttle plates open and the turbos come on. Your strongest readings will be at idle and cruising with little throttle. Mine pulls -10psi and idle and around -6psi at highway speeds. It quickly drops to zero once you get on the throttle as there is no more vacuum in the lower intake manifolds and the slight vacuum made in front of the turbos for the secondary CCV connections are barely enough to keep the crankcase at zero pressure.
Yes the BMW engineers in charge of the CCV system need to dragged into the street and publicly humiliated for their incompetence. A new class action lawsuit was just won against BMW with the N63TU burning oil due to their poor engineering of the inadequate CCV system and valve stem seals. That's over a decade to fix the issue and they have not. BMW is made up of different engineering teams, some brilliant, some absolute incompetent idiots (or possible Mercedes saboteurs
). I personally believe the idiots in charge of the CCV system at BMW are the same idiots that still to this day say transmission fluid does not need to be changed and lasts a lifetime....
Less oil consumption, less oil leaks, better sealing of the piston rings are all benefits. There are zero downsides to running CC pressures at -10psi, other then the cost of the system. I'm at nearly 180k miles, burn less then half a liter every 5k oil change , and my rear main seal which was leaking like crazy before I installed the CCV system stopped and had not produced a drop of oil in 80k miles since I installed the system.
Perhaps that is just it, a proper CCV system would cost BMW to much money in terms of lost service fees and people trading in their "leaky oil burning" rides for the newest model.
When you say the turbos don't spool, do you mean they fail to generate boost and the truck is slow or do you mean you just don't hear them spool?
That's awesome news in the one way from jegs, I'll check them out.