Mid November, I noticed my oil level was at the minimum mark on the dipstick. After topping it up with a half a liter of oil, I pulled the dipstick again a few weeks later and noticed it was almost at the minimum mark again. I was losing about 500mL of oil every 2 weeks. I was due for an oil change so I topped it up again for now. When I got under the car and removed the belly pan, I saw the oil mark as well as oil on the pan. I have a 2019 with 25,000KM's with Audi Care. The dealership would not cover the work.
This repair took me two days taking my time. I let the car sit for the first day while it drained to let as much oil seep down as possible. If you do this repair over the course of two days, I would suggest not leaving the upper oil assembly exposed. I used 4X bolts and re-installed the lower oil pan just to prevent any dust or debris from getting into the assembly.
List of tools you will need:
- T25, T30, T45
- New 25X oil pan bolts (This is optional). Part # is N-911-687-01. Audi dealership quoted me $370CAD after taxes. Almost $12 per bolt. Go to a VW dealership. They charged me $3.30/bolt, or around $100CAD total. I bought 28 just in case. The factory service manual says to replace these bolts once removed. I'm not sure if they are stretch bolts, or they did this just because it's easier to use new ones.
- Flathead screwdriver + square head screwdriver
- Putty knife
- Two cans of brake cleaner
- Permatex Black "The Right Stuff"
- Permatex gasket remover (or any type of silicone remover)
- Razor blades (Plastic or metal)
- Plastic trim tools
- Brass brush
- 3 zip ties
- Torque wrench that goes down to 3Nm
- Microfibers
- Lots of broken down cardboard boxes
STEP 1
Get the car up on jacks. You want clearance under the car. Using just low profile ramps will not give you enough clearance to do this repair. Remove the belly pan. There's 3X T45 at the back, and 6X T25 on the sides
STEP 2
Drain the oil from the oil pan. Drain bolt is T45.
STEP 3
Drain the oil from the filter. There's one hose that's slightly in the way here. I used a zip tie to pull this hose to the front of the car. This just makes the following steps a little easier. First remove the little cap, which will expose an orange nipple. I used a square-head screwdriver to push the nipple up and drain that oil out. There's quite a bit in there and you want to drain this before removing the oil filter housing. Once you drain that oil out, use a 74mm 14 flute oil filter wrench and remove the housing to expose the filter. Install new gasket + filter and torque back down to 15ft/lbs.
STEP 4
Disconnect the cable from the oil level sensor. Use a flathead.
STEP 5
There's 3 tabs that hold the oil level sensor cable onto the oil pan. These were a pain to take off the oil pan. They are plastic on the outside and have metal tabs on the inside which bite. I used a very small flathead in combination with a plastic trim tool to shimmy them off. They are marked with yellow and are easy to see.
STEP 6
Zip tie the oil level sensor cable to the hose in the prior step. You want a clear path when you drop the oil pan and re-install it. You do not want to be moving this cable out of the way when you have fresh sealant on the oil pan and are trying to lift it back up to the upper assembly.
STEP 7
Drop the oil pan. Use a T30 on the 25X oil pan bolts. Diagram below shows which bolt to start at and the sequence to follow. The pan will be stuck to the upper assembly, so don't worry about it just falling on you.
STEP 8
This is where the putty knife came in handy. The front of the oil pan (side that has the sensor) does not have enough room to work with. I worked from the back of the oil pan (drain bolt side) and wedged my putty knife in there to cut thru the sealant. Start at one of the corners of the pan and use corner of the putty knife to cut through. Once through, work your way along the whole back side of the pan. Once you have freed up this entire side of the pan, place the putty knife in the center of the side you just freed up and rock it up and down carefully. This was all it took to break the oil pan free from the upper assembly for me. The putty knife will help get most of the pan off, then just wiggle the rest of the pan free. The top part of the assembly is machined, while the oil pan is just flat aluminum. The putty knife did a good job of not scoring either of those faces.
STEP 9
Cleaning the oil pan. This is the tedious part. First drain and clean the inside of the pan off with brake clean. The factory service manual suggests using a rubber brush attachment for a drill. I did not have this and opted to use razor blades, a plastic trim tool, a brass brush and silicone remover. I did this in 4 stages.
Stage 1: I first used the razor blade to take the thick parts off the edges of the pan. If you are using a metal razor blade, please go slowly and keep the blade as flat as possible. You want to avoid gouging the surface of the oil pan.
Stage 2: Silicone remover and brass brush. Soak the pan in the silicone remover, let it sit a bit, and start brushing lightly with your brass brush. The brass brush did a good job of not scoring the surface of the oil pan while remove the silicone. This took over an hour. I did try and use a hard, plastic bristle brush at first but it did absolutely nothing.
Stage 3: Eventually you're left with silicone sitting in the channels. Here, I used a plastic trim tool and ran it along the edges of the channel to cut most of the silicone out. Once you take that big chunk out, use the trim tool to scrape what you can out, then follow up with the brash brush and silicone remover to get the remainder out. The pan should look completely spotless once you're done. I used a level once the pan was clean and ensured all the sides of the pan were flat and there was no deformation anywhere.
Stage 4: Clean the pan thoroughly with microfibers and follow up with lots of brake clean. There will be bits of silicone everywhere. I think I used a full can of brake clean.
STEP 10
Inspect the upper assembly where you mount the oil pan too. There was almost no trace of any silicone here. I sprayed some brake clean on a microfiber cloth and cleaned up whatever oil I could, and then went around the perimeter with my brass brush very lightly. Any silicone that was left was a very, very thin layer and didn't take much pressure to take off. One thing you will notice is that oil will keep dripping out from the upper assembly down onto this mating surface. I did this repair over the course of two days and oil was still dripping down up until the point I mounted the oil pan.
STEP 10.5
Right before you're ready to start applying Permatex to the oil pan, give the upper assembly one last wipe down. Chances are, there's fresh oil on the surface. This surface needs to be free of oil when you mount the pan. Try and dab up as much oil from the inside of the block to prevent more oil from running down on your mating surface. I still had some oil make it's way on the mating surface after two days of letting it drain. Keep a microfiber cloth and brake clean in arms reach in case there is some oil when you go to mount the pan. I also did some "mock runs" with the clean pan, pretending I just applied the RTV and needed to install the oil pan. This helped me plan out how I would need to move and position myself once the Permatex was on the pan.
STEP 11
Time to apply the Permatex Black "The Right Stuff" to our oil pan. Give it one final inspection and one more blast of brake clean to ensure the surface is clean. You'll want to cut the tip of the nozzle so it generates a 3mm bead of sealant. Start with a small cut, run a small bead on a piece of cardboard and measure. The channels on the oil pan are about 3mm wide for reference. Too little and you won't get a good seal. Too much, and you'll have silicone hanging off the side on the inside of your oil pan. You don't want that breaking loose.
Start at the arrow and work your way around. The bottle says once you start applying the RTV, you should install the part within 5 minutes. This was my first time using RTV and it took my about 9 minutes just to go around the perimeter and then around each of the holes. It's pretty hard to apply a nice bead of this stuff while completing it in 5 minutes. I focused on applying a nice, even bead. I wanted to get a picture of the bead on the pan but I was rushing by the end.
STEP 12
This was the hardest part. I gave this step a lot of thought because my mock runs showed me how hard it was to line the oil pan up with the upper assembly. SEE RED ARROW. This first bolt is used as our anchor. I only installed it to where the bolt threaded in a few turns. Just enough to where the pan is still suspended in the air, but none of the Permatex is touching the upper assembly. Once you have your anchor bolt in, follow the instructions and install the bolt at the black arrow. Install the bolts by hand tightening them until you feel the Permatex just starting to get smushed.
My wife helped me here. She sat beside the car and put on a few dabs of Permatex close to the base of the bolt and handed them to me. I don't think adding some additional Permatex to the bolt is necessary, but it can't hurt.
Once I installed all 25X oil pan bolts by hand, I put my T30 on a 2" extension and hand tightened them down again some more until I saw the Permatex getting pushed out the side of the oil pan. This does not require a lot of force. It takes minimal force until you feel some resistance. The torque spec is only 3Nm and a bit, so do not hand tighten it to the point where you're struggling. We just want the Permatex to flatten out before it cures. Once you do this second lap of hand tightening, set an alarm for 60 minutes and let the Permatex cure.
After 60 minutes, go back in with your torque wrench set at 3Nm. Start at the black arrow and torque down all the bolts to 3Nm. Once you do this to all 25 bolts, go back in and torque down each bolt an additional 45 degrees using the same sequence.
STEP 13
Permatex RTV says to wait at least 90 minutes before refilling the oil. It was still pretty tacky after 60 minutes, so I just waited a full day before replenishing the fluids. You'll want to cut the zip ties we used to secure any hoses. Re-install the oil level sensor cable as well and mount the clips back onto the oil pan. Reinstall drain plug, fill up oil, and check for leaks before starting up the car. Check for leaks again after the first drive.
Huge thanks to David and Tristan for putting up with all my questions.
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Originally Posted by 949
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