Help me investigate an oil leak (pictures)

[GolfVFSI]

Hi everyone,

My sister in law recently purchased this Golf 6 1.4L TSFI.
2 weeks later she noticed this oil leak coming from underneath the car



My sister in law took the car to a mechanic and they did oil change + new drain plug and crusher washer.

A few days later, she noticed only 2 new drops underneath the car, nothing like the first big leak shown above.

I asked her to bring the car to me to have a look. I visually inspected the drain plug which is clean and dry, positive it's not leaking from there. My theory is that when the previous owner serviced the car before selling the car, their mechanic probbaly didn't replace the and re-used the old one and that's what caused the initial heavy leak. I mean it's not just a drip that's a big leak, besides oil leaking from the drain plug I don't see what else it could have been?

Anyway, then I removed the underbelly cover and noticed that the left side was definitely oily



Upon closer inspection I noticed this area which had a build up of oil, with a drip about to drop. Can someone tell me what the part highlighted with the red arrow is?



I also inspected the oil pan and noticed that 2 screws were dark/oily while all the other srews around the oil pan were clean and dry so I'm suspecting a little bit of a leak there, but it looks within tolerance for a car this age, what do you think? To me, it doesn't look like what caused the heavy leak in the first picture above.



I also noticed this hose junction with a lot of oil build up. Does someone know what his hose connected to?



I put a cardbox underneath the car and no drip over the last 48h. So I'm thinking that that major oil leak was fixed when they replaced the drain plug + crusher washer.
What are your thoughts on the oil deposits found on the bottom left of the engine? Is it a "normal" amount of oil for an old engine?

Let me know your thoughts, thanks.

[MIG]

Spray the whole area down with brake clean or another degreaser, then have another look in a few days. the oil pan gasket may be weeping in that area.
The AC compressor is highlighted; no engine oil can come from that.

[GolfVFSI]

Spray the whole area down with brake clean or another degreaser, then have another look in a few days. the oil pan gasket may be weeping in that area.
The AC compressor is highlighted; no engine oil can come from that.

Thanks for the reply.
Ok so that's the AC compressor. That rules it out as a source of oil leak.

I guess the only other potential source for the leak is the oil pan gasket I highlighted.
I cleaned the area and will have another look in a couple of days.

Thanks, it helped a lot

[h100vw]

A ton of oil escapes if you remove the oil filter too quickly. It runs through the alternator and off the compressor. These are not totally oil tight engines.
Maybe the timing chain has been replaced and the case isn't sealed as well as factory.

[GolfVFSI]

A ton of oil escapes if you remove the oil filter too quickly. It runs through the alternator and off the compressor. These are not totally oil tight engines.
Maybe the timing chain has been replaced and the case isn't sealed as well as factory.

Thanks for your input. That's a good point, seeing that the oil filter is facing up, I could see oil drip down from above when removing the oil filter. Might explain the traces of oil residue underneath on the alternator and compressor.

Timing belt was replaced by the previous owner so hopefully they resealsed the case correctly. Any giveaway that would indicate that the case wasn't properpy sealed? Where should I look? Is it on the side of the visible accessory belt (the one that run through the alternator)

I mean a little bit of oil leaking isn't a problem, it's just that big oil leak on the first picture I'm worried about. Hopefully it was a bad crusher washer and hopefully it's been fixed when we replaced the drain plug + crusher washer.

It's been 2-3 days and no new drip. I was wondering if it could be because I didn't drive the car? With these things, is it more likely to leak when oil is hot/engine running?