Oil filter cap seepage

Nero Morg

Veteran Member
Joined
Oct 19, 2017
Location
OR
TDI
2003 Jetta wagon, 2001 Jetta TDI, 2014 Passat TDI
Well I've got an odd one. Seems my oil filter cap may be pushing oil. It was like that when I changed my oil last, so I cleaned it up. This was a few months ago. Was looking over my engine last night, and it's oily again. It's definitely the cap area, as it's seeping just down the front of the filter housing, starting at where the cap meets the housing.
I always pre lube the o rings before installing the filter. Are these caps known for cracking or leaking? I haven't pulled it off yet to inspect it further.
 

ahldailydriver02

Veteran Member
Joined
May 9, 2019
Location
Arlington, Ne
TDI
02 Jetta 5 speed, 03 Jetta Wagon 5 speed
I would make sure you have your o ring still in place. Also I had one of the caps go bad on me before. I couldn't see any crack in it but it did the exact same thing that you are experiencing right now. I replaced my cap 150,000 miles ago and no problems since then.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Replace the filler cap gasket. If that doesn't work, replace the cap. But it's usually the gasket.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
That big o-ring can get deformed or out of position, especially if over tight. Just take it off and have a look.
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
I've only replaced that big cap o-ring a few times on each of the TDIs over their lifetimes (so far). Never had a leaker yet and had trouble on the occasion I replaced it with a new one. Seems like every VW I've come to own or work on has the cap way overtightened.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
you get the hengst filter with the white o-ring?

they aren't actually oil-compatible
leave one in solvent overnight, it'll be 6x the size it was and mushy
 

Nero Morg

Veteran Member
Joined
Oct 19, 2017
Location
OR
TDI
2003 Jetta wagon, 2001 Jetta TDI, 2014 Passat TDI
you get the hengst filter with the white o-ring?

they aren't actually oil-compatible
leave one in solvent overnight, it'll be 6x the size it was and mushy
No I've always used either Napa Gold or Mann filters, they both come with the black o ring. I'll pull the cap soon and see what's going on, it's due for an oil change anyways.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
The Mann filters (which I use) all have come with both the cap O-ring and the little one for the "stick"; I replace both with the filter.

If a new O-ring doesn't fix it then the cap has almost-certainly cracked where you can't see it. While it's POSSIBLE the housing is scored (which would prevent a seal) I very much doubt that happened.
 

Nero Morg

Veteran Member
Joined
Oct 19, 2017
Location
OR
TDI
2003 Jetta wagon, 2001 Jetta TDI, 2014 Passat TDI
Well popped the hood and took a closer look, very slight bubbling here. Oh boy. I think I'll just order a cap to play it safe, because I always replace both o rings each time I do the oil.
 

Ground Beef

Member
Joined
Mar 10, 2006
Location
Burke, VA
TDI
2002 Jetta TDI
I had this problem once. The guy who changed my oil didn't take the old O-ring off, so I had two. I drove it for months before it suddenly started leaking profusely. Took off the extra one and everything was good.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Note that you should never use ANY tools on that cap when removing the old O-rings. It's plastic -- score the groove where that O-ring rides and seals and it's done.

I just squeeze it with my fingers to get enough gap to grab, and off it comes. Ditto with the bottom one for the same reason.
 
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