Help Needed: Oil Filter Cap Leak

Last weekend, I performed my 40K service, with no issues. The car ran fine all week, no inidcations of problems, although I did not check the oil level during the week after the day of the service. Today, I drove to the beach and back (about 1.5 hours round trip). After I got back in the car to run an errand, I pulled back and noticed a large pool of oil inder the car. I checked the oil, and it was very low.

I pulled the car into the garage and onto my ramps. I unbolted the belly pan, which was covered in oil. There was oil all over the underside of the engine, but no inidication of damage. I cleaned it up the best I could, added about 1.25L that I had left over from last week, and started it back up to look for the leak. It was clearly coming from the oil filter cap, about an inch worth of the circumference. And it was definitely more than a trickle.

As karma would have it, I don't have the 32mm socket to pull the oil filter cap (I usually do my service at the auto hobby shop on base). So, I'll buy one tomorrow, and check the condition of the O-ring/gasket, and the cap. Of course, I'll either have to go the VW dealer on Monday for a new one, or order one from TDIparts (unless they are available from the auto store?).

Ok, questions.
1) Why would the oil filter cap/gasket all of the sudden start leaking? I saw no oil at all this week, and then all of the sudden a whole bunch.
2) Should I first just re-torque it and start it up to see if it still leaks?
3) If I pull the filter, am I required to replace the gasket? Or can I reuse it since it is only a week old?
4) Any recommendations on oil I could get at Autozone or Advance, or should I wait for an order from TDIparts (my usual source)?

I'm pretty pissed. Hopefully, this is just something simple, but this is really the first issue I've had with my TDI. Bursts my bubble.

--Mark

If it (the O Ring) is hosed you may be able to find a new 0 ring at a good hardware store or at Home Depot that will work.

I would expect to find the 'Oil Filter Cap O-ring' to have been damaged when you tightened to filter cap.
Call the dealer and see if they have one.
When you replace it, make sure it is at the TOP of the cap and not stuck in the threads.
Lube it with a little oil.
Tighten hand tight.
Use the same type of oil (505.01 or 506.01 or 507.0?) that you used for the last change, if you can find the same type of oil you can simply top it off.

Spray the engine with Simple Green and hose it all down at the car wash....

Things happen....

Bill

Most leaks like this are cause by putting the O ring into the wrong groove on the cap.

Walt

Use an adjustable wrench on the filter cap. That's what I use.

30mm socket on a torque wrench works as well...

I just use two hands

Oil

You can NOT get oil at autozone,walmart, advance auto parts, ect! They do Not sell 505.01 oil!

Update

I got the filter housing open, and it was just as everyone said - O-ring problem. The O-ring wasn't sitting in the proper channel; it was sitting in the little space between where it was supposed to be and the cap. If you look at this space, there are 4 little vertical pieces of plastic in this space, and those pieces were cutting into the O-ring on all 4 sides. Where the leak was, the cut had finally made it all the way through the O-ring cleanly. My guess is the oil pressure had been slowly forcing the O-ring onto the plastic parts, slowly cutting them, so that yesterday, finally one of them cut through. I'm not sure if I screwed it up when I installed the ring, or it got pushed up there when I screwed the cap on.

That's good news - no big deal (I don't think any engine damage or anything happened - no oil pressure warning or anything like that). Tomorrow, I'll run by the VW dealership and pick up a new filter and 5L of oil. (I would order from TDIparts as usual, but timeliness is important tomorrow) The hard part now will be cleaing up all the oil from all the little crevases of the engine and the undercarriage!

Thanks everyone for your input.

--Mark

dhdenney said:

This just in from the completely random department.

Click to expand...

While I would normally agree with your assessment, he was replying to question number four from the OP.

airwolf said:

While I would normally agree with your assessment, he was replying to question number four from the OP.

Click to expand...

Ah, post deleted.

Putting the o-ring in the wrong groove is easier than you might think. I consider myself fairly capable and astute when working on cars, but I sure enough didn't get the o-ring installed correctly on the oil filter cap at my 20K oil change. I have had a slow leak around the cap that I hadn't figured out until I saw this thread. When I changed oil again just now at 30K, I see that the o-ring was up by the threads and not in the groove that is was supposed to be in.

Lesson: When reinstalling the o-ring it goes in the larger smooth groove and NOT right next to the threads. When screwing the cap into the canister, make sure the o-ring stays in the groove and doesn't pop out. Lubing the o-ring helps. That may have happened in my case.