ccv bypass piped with metal?

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
There is no way for the tubing to freeze up. The reason is there is always warm gasses flowing out of the engine. If you use 3/4" ID hose routed under the car it will work perfectly. This is how I have my 2000 TDI auto set up.

The TDI engine is always under positive pressure due to the vacume pump pumping air into the engine and the blow-by gasses. Iven if sno somehow got jammed into the tubing intentionaly the pressure and warm/hot air in the engine would melt it.

DB
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
There was indeed a person on Fred's whose ccv bypass got an ice plug and lost a lot of oil before he noticed. No alarm went off since there was still pressure. I think he had it routed under the car. If VW has a heater built in for that very short run, there must be a concern.
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
The diameter of the inlet into the intake has a restriction that has the effect of dropping the temperature and forming ice. VW integrated a heater element to reduce the chances of freezing. Because I only use a contstant diameter hose there is not pressure drop resulting in possible freezing.

I believe the one incident of freezing was because snow got compacted in the inlet due to being stuck in snow and not because of ice formation from the gasses. When you mount the hose make sure it is mounted facing aft and not verticle.

DB
 
M

mickey

Guest
They put a heater in the CCV inlet to avoid icing. So it must be possible. I don't spend a lot of time worrying about it, though.

-mickey
 
M

mickey

Guest
I would point out that the CCV normally dumps into an airstream that can be VERY cold in the winter. If it's 20 below zero, that air rushing past the CCV inlet is going to be a bit chilly. I can see what it might ice up at that point.

However, if a bypass hose is routed through a generally warm place (and aren't they all?) I don't see them icing up.

-mickey
 

GeWilli

Top Post Dawg
Joined
Aug 6, 1999
Location
lost to new england
TDI
none in the fleet (99.5 Golf RIP, 96 B4V sold)
one of the icing up happened with a Racor filter.

but that was up nort in da u.p. of mitcheegan

IF you filter the stuff (rather than dumping it down into what ever) you will need a provision to keep it at engine temps when running and set up so that if it does ice up it won't create any blockage - IE warm enough to let the water drain before it freezes . . .
 
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