Oil Leak front right side...Not sure of source??

[Valleyrally_01]

We have a '13 S4 with about 125K KM on it.. bought it used last summer. Was doing an oil change this morning and when I went to remove the belly pan/skirt, I noticed on of the screws toward the front right side holding it on was oily... not a good sign.

Once I removed the pan, I found oil was all over the oil pan and was blown back in behind it and also a ton (perhaps the origin of the leak?) was up in behind the intercooler(?) on the front right side... where the large hose comes down and goes into the rads. THat said, I am completely new to the S4 and the inner workings of the supercharger and/or cooling system.

I've read through a number of threads on oil leaks and so far I've not seen anything exactly like this. But suspected sources so far are Rear main seal, seal or o ring in the trans oil cooler lines... but again, I am not terribly familiar with this car yet so I could be talking out my A$$.

at any rate, any thoughts on what this might be would be hugely helpful. I'd like to get a better idea before I bring it in... hoping I wont need to.

20210321_142050.jpg20210321_142104.jpg20210321_142159.jpg

[djn876]

It doesn't look like trans fluid, the rear main would be in the back not all over the front like that. Is it coming from above? Check the valve cover gaskets, they are a popular spot to leak from.

[prabkaler]

Would just wash the car off underneath and take it for a spirited drive. Wherever you see the oil seeping out first will most likely be your culprit. Could really be anything, oil pan, timing covers, oil cooler, etc.


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[B7TitaniumA4]

Fwiw, I’m doing an engine out maintenance blitz and my engine was leaking from the following spots, 2013 6mt at 97k miles...

Both upper timing covers (replaced both)
Rear of the oil pan (replaced pan, sensor and hardware)
Oil Drain plug (will be extracting oil during future oil changes)
Oil cooler (new gasket/ hardware)
Oil filter housing gasket (new gasket and new housing cause I dropped and broke it )
Both valve covers/gaskets/hardware (opted to get new ones cause my old ones are stained badly)
Possible rear main seal (haven’t pulled the flex plate yet)
My axle seals may be leaking by visual inspection so far but I have not started working on the trans yet.










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[Valleyrally_01]

Would just wash the car off underneath and take it for a spirited drive. Wherever you see the oil seeping out first will most likely be your culprit. Could really be anything, oil pan, timing covers, oil cooler, etc.


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That's what I've done. Cleaned it as best I could and will drive as normal for a week...reassess on the weekend. Got a buddy with a lift so will get it in the air and have a good look.

- - - Updated - - -

Fwiw, I’m doing an engine out maintenance blitz and my engine was leaking from the following spots, 2013 6mt at 97k miles...

Both upper timing covers (replaced both)
Rear of the oil pan (replaced pan, sensor and hardware)
Oil Drain plug (will be extracting oil during future oil changes)
Oil cooler (new gasket/ hardware)
Oil filter housing gasket (new gasket and new housing cause I dropped and broke it )
Both valve covers/gaskets/hardware (opted to get new ones cause my old ones are stained badly)
Possible rear main seal (haven’t pulled the flex plate yet)
My axle seals may be leaking by visual inspection so far but I have not started working on the trans yet.










Sent from my iPhone using Tapatalk

Damn! I'll be right over... we can do mine next! LOL ;)

[Valleyrally_01]

Anyone have a resource for engine diagrams for these cars? Something like this: https://sparepartsfinder.ktm.com/Com...&isEngine=True

It would probably help if I knew what parts I was talking about when posting in the future....lol!

[MSq5]

We have a '13 S4 with about 125K KM on it.. bought it used last summer. Was doing an oil change this morning and when I went to remove the belly pan/skirt, I noticed on of the screws toward the front right side holding it on was oily... not a good sign.

Once I removed the pan, I found oil was all over the oil pan and was blown back in behind it and also a ton (perhaps the origin of the leak?) was up in behind the intercooler(?) on the front right side... where the large hose comes down and goes into the rads. THat said, I am completely new to the S4 and the inner workings of the supercharger and/or cooling system.

I've read through a number of threads on oil leaks and so far I've not seen anything exactly like this. But suspected sources so far are Rear main seal, seal or o ring in the trans oil cooler lines... but again, I am not terribly familiar with this car yet so I could be talking out my A$$.

at any rate, any thoughts on what this might be would be hugely helpful. I'd like to get a better idea before I bring it in... hoping I wont need to.

20210321_142050.jpg20210321_142104.jpg20210321_142159.jpg

Uh, given the location and the largest amount of oil on the under tray, maybe first check the canister oil filter housing. There is both a filter gasket that goes in the bottom of the removable cap, and an o-ring that goes in a groove on the inside of the part of the housing that is attached to the engine. Both are necessary. You need a 36mm oil filter socket to remove tbe canister housing cap.

Sometimes independent shops just replace the gasket during an oil change and not the o-ring, or don't get the o-ring installed in the groove it is supposed to fit. Get that wrong and you get a leak that drips down onto the under tray.

Always check simple, common things first and exclude them before assuming something more complex.

There are some photos on Eli's FCP Euro video (step 3 or 5:10 on the video) of the oil canister housing, gasket and o-ring here:


https://blog.fcpeuro.com/audi-sq5-oi....5-a4-a5-s4-s5

[Valleyrally_01]

Uh, given the location and the largest amount of oil on the under tray, maybe first check the canister oil filter housing. There is both a filter gasket that goes in the bottom of the removable cap, and an o-ring that goes in a groove on the inside of the part of the housing that is attached to the engine. Both are necessary. You need a 36mm oil filter socket to remove tbe canister housing cap.

Sometimes independent shops just replace the gasket during an oil change and not the o-ring, or don't get the o-ring installed in the groove it is supposed to fit. Get that wrong and you get a leak that drips down onto the under tray.

Always check simple, common things first and exclude them before assuming something more complex.

There are some photos on Eli's FCP Euro video (step 3 or 5:10 on the video) of the oil canister housing, gasket and o-ring here:


https://blog.fcpeuro.com/audi-sq5-oi....5-a4-a5-s4-s5

Interesting! Now that you mention it, when I did my oil change, I noticed that the filter was missing the that o-ring you're referring to. But I also had a better look around the engine bay and noticed quite a bit of oil residue along the gasket of the drivers side valve cover... it's been weeping for some time...not wet but a fair bit of old dusty oil build up on the underside edge.

At any rate should be interesting to see if the leak comes back now that that o-ring is in place....fingers crossed!!

Cheers ;)

[Valleyrally_01]

Figured out where the leak is coming from... as mentioned, I cleaned everything up as best I could... drove it for a week and checked it today. Once I got under I could clearly see that the top right side pressure line going into the intercooler was wet with oil... the area I originally found was directly beneath this. Likely the o-ring needs replacing, unless there's a known issue with these that I dont know about.

IT's a $2 part, but I am wondering whats involved with disconnecting these lines? Can I simply disconnect it, replace the o-ring and reconnect?? I have a feeling it is a bit more involved as it is a pressure line....?? Any pointers on this are greatly appreciated.
Pic of what I am talking about: Part #1 is the line in question, #2 is the o-ring Im thinking is the issue.
Screen Shot 2021-03-27 at 4.16.12 PM.png

[MSq5]

Figured out where the leak is coming from... as mentioned, I cleaned everything up as best I could... drove it for a week and checked it today. Once I got under I could clearly see that the top right side pressure line going into the intercooler was wet with oil... the area I originally found was directly beneath this. Likely the o-ring needs replacing, unless there's a known issue with these that I dont know about.

IT's a $2 part, but I am wondering whats involved with disconnecting these lines? Can I simply disconnect it, replace the o-ring and reconnect?? I have a feeling it is a bit more involved as it is a pressure line....?? Any pointers on this are greatly appreciated.
Pic of what I am talking about: Part #1 is the line in question, #2 is the o-ring Im thinking is the issue.
Screen Shot 2021-03-27 at 4.16.12 PM.png

Glad you found it! I regret I don't know how to safely disconnect the line to replace the o-ring. Hopefully, someone will come along with experience. Since its an oil line, I don't think there will be any issue with remove and replace, but I don't know.