I have an 09 3.5 tl with just over 160000 miles on it. I’ve had the car for over a year now, and within the past month or so I’ve started noticing dark stains showing up on my driveway. I got under it to look and found a large amount of what appears to be oil covering the underside of the engine on the passenger side. I have been wanting to save money and learn to work on cars myself, but I’m unsure as to what exactly the oil could be coming from and how I could locate this leak? Btw I just had my oil and filter changed along with trans flush about 5 months ago.

Underside of engine from passenger side, view is facing toward rear of car with passenger side wheel to the left. I can get a better picture if necessary

 

Get under there and clean off the oil. Did you replace the crush washer on the oil drain plug or check to make sure it’s on there tight?

 

Looks like it is coming from the drain plug and that nut looks stripped

 

I got under and cleaned off the oil and the plug is on really tight, there doesn’t seem to be any faults with the plug or washer, however I have an untrained eye so idk. I also happened to notice a coolant leak down there as well coming from what appears to be right above the oil pan and I have no idea where that could be coming from.

Drain plug

Front of oil pan

 

Do you know when your water pump was last replaced? If you are lucky you may have a leak at a coolant hose, or you may be in for some bigger repairs. Please replace your oil drain bolt on your next oil change.

 

I don’t think the water pump has ever been replaced, I received the service history when I purchased the car dating back to when the car was first sold new and there is no record of it. I have looked over and under around the area and found no lines that are leaking I can only find the fluid on top and below the oil pan. Would the water pump be the most likely culprit?

 

- Yes, the water pump is the most likely leak point for the coolant.
I recommend you have it replaced with OEM or Aisin brand kit.
The water pump is behind the timing belt so it's easiest to replace during a timing belt replacement.
- Oil leak could be from several sources.
2 common sources shown here: Main oil seal (Item 21) and oil filter adapter oil seal (Item 13).
Access to replace Item 13 is easiest if you remove the pass front tire.
Item 21 can be replaced during a timing belt replacement.
https://www.acurapartsforless.com/v-...gine--oil-pump
- There is a slight possibility the camshaft seals are leaking oil.
Again, those can be replaced during a timing belt replacement.
- If the rear main seal is leaking the transmission has to be removed for access to replace.

 

I appreciate the input. After further examination I find that it is probably time for that water pump to be changed. I ordered a kit for the timing belt and water pump to be replaced and will be doing so within the next day or two. As for the oil issue I will have to take a closer look while I am replacing the timing belt and water pump.