crankcase pressure

ss010949

Member
Joined
May 12, 2019
Location
levittown NY
TDI
2003 jetta wagon , 2014 audi Q7
im not sure where you would this problem . anyway , how much pressure should there be in the crankcase when running . on my other engines , i can add oil or dye to the crankcase while its running . i tried to put dye in my ALH (wile running) , to find my oil leak , and non of it went in . went every place but in . have 370,000 miles on my ALH . whats wrong ?
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
If there's actual flow coming out as opposed to pulsing you could have a vacuum system leak since the vac pump exhausts into the valve cover. How loose is the 1/2" or so fitting on the inlet to the pump?

Other possibilities are the TC and, of course, rings
 

ss010949

Member
Joined
May 12, 2019
Location
levittown NY
TDI
2003 jetta wagon , 2014 audi Q7
that fitting wiggles around quite a bit , but i can't pull it out of the pump . how much play should there be , if any .
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
You could buy a new pump. Some have peened the end of the pump to tighten the fit but I figger if it's that loose the seal inside is shot. I and others have had success sealing it with epoxy. Like JB Weld. Clean it good with contact cleaner spray.
 

braddies

Well-known member
Joined
Jul 26, 2021
Location
America
TDI
03 golf ALH
Had a really loose vacuum pump nipple that ended up "cured" by first cleaning really well all around, heating the round housing with a propane torch and tapping the outside edge in with a ball-peen hammer, then clean again and smeared black RTV around the edge, Rock solid after that
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Since the nipple is held in by rolling the edge of the pump housing I don't see a seal replacement as viable. The housing would prolly crack when the nipple was removed.

I don't know if there's an o-ring on the OD of the nipple or some sort of face seal between it and the pump. If it's a face seal that's still soft recrimping may fix it by recompressing that seal.

Whatever sealant one uses I'd clean it good first and try to work said goo between the nipple and housing. Before peening it if that were to be done.
 

braddies

Well-known member
Joined
Jul 26, 2021
Location
America
TDI
03 golf ALH
Whatever sealant one uses I'd clean it good first and try to work said goo between the nipple and housing. Before peening it if that were to be done.
Yes, and since it's pulling vacuum through there it will effectively be pulling air (and RTV) IN from the outside, if I'm understanding this right
 
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