u/ColeMac4500

(Keep in mind this oil fill doesn’t let you look into the engine!!!!)

Just did the first oil change on a 2013 Jetta TDI (CJAA) I bought with unknown history. Before draining the oil, I found very thick black tar-like sludge in the oil filler neck/cap area (video attached). I then changed the oil and filter with correct VW 507.00 oil.

The filter looked normal, and the drained oil also looked normal—just black diesel oil with no sludge or metal. The car runs, boosts, and drives completely fine with no issues.

My dad has the exact same car but his is deleted and highway-driven and is spotless there. Mine has been mostly short-trip driven its whole life.

I’m planning to drive it ~1000 km and re-check everything, then likely do another oil change.

2013 Jetta TDI (CJAA, manual) — I’m trying to track down a fluid leak and I’m a bit stuck. It’s dripping from behind the engine underneath the car, and the wettest area is on the steering rack/subframe near the exhaust tunnel. The fluid is clear to slightly yellow, very thin, and it doesn’t smell like anything at all—no coolant, diesel, brake fluid, or oil smell, just neutral.

The engine bay looks dry, coolant and brake fluid levels are fine, and I don’t see anything obvious on the transmission. The steering is electric, so there’s no hydraulic power steering fluid. The A/C doesn’t work and just hisses when turned on. The previous owner said the A/C was refilled last year, worked normally for a while, and then gradually stopped cooling.

The fluid seems to run along the subframe and collect around the steering rack area before continuing toward the back of the car. I’m trying to figure out if this is most likely an A/C system leak (compressor oil/refrigerant) from a line, condenser, or compressor seal, or if there’s another common Mk6 TDI leak point in that area I should be checking?