Mine puffs out quite a bit of blowby with the cap off (makes it dance if you loosen it) and yet it starts within 6-7 cranks at 0F, so I wonder how much of a problem it really is, it probably has to get reeeeal bad before major problems occur from it. It doesn't puff out any more now than it did 30,000 miles ago, so who knows......our '83 has essentially no blowby (nothing out of filler-hole with the cap off) and yet it doesn't start any better in the dead of winter than mine does.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)