Oil pan issues 04 xc70

Mehka01 · Post by **Mehka01** » 07 Jan 2026, 11:56

So I replaced my oil pan. It sealed around the pan to the engine block just fine, sealed the oil cools just fine as well but still leaks oil. This is an aftermarket pan that matches oem very closely. Upon inspection I find 2 plugs that also exist on the original pan (I no longer have the original pan because of where I live but I did confirm this before discovering the problem) and both of them are leaking. I checked the thread and it seems to be metric not npt. It surprised me to find that with no sealant of any kind and im not sure what I should be using to seal it. Anaerobic?? I tried teflon and loctite red but no luck. Locktite failed immediately and teflon wouldnt even go in due to non tapered seat I suppose. Any suggestions? I would prefer to get this done as correctly as possible

Mehka01 · Post by **Mehka01** » 07 Jan 2026, 12:00

Just to clarify these plugs are located near the oil filter and take a 10mm Allen key to remove on my pan. Original may have been a star bit but I cant find much information on them and Google Ai tells me its a 17mm not a 10. Lol wrong plug.

Post by **Krons** » 07 Jan 2026, 17:40

This kit has what you need.
https://www.fcpeuro.com/products/volvo- ... -reinz-kit

While you have the pan off, you should really pull the oil pick up and change the O-rings for it. As those O-rings get old and brittle they can suck air causing low oil pressure issues.

Post by **volvolugnut** » 07 Jan 2026, 18:43

Mehka01 wrote: ↑07 Jan 2026, 11:56 So I replaced my oil pan. It sealed around the pan to the engine block just fine, sealed the oil cools just fine as well but still leaks oil. This is an aftermarket pan that matches oem very closely. Upon inspection I find 2 plugs that also exist on the original pan (I no longer have the original pan because of where I live but I did confirm this before discovering the problem) and both of them are leaking. I checked the thread and it seems to be metric not npt. It surprised me to find that with no sealant of any kind and im not sure what I should be using to seal it. Anaerobic?? I tried teflon and loctite red but no luck. Locktite failed immediately and teflon wouldnt even go in due to non tapered seat I suppose. Any suggestions? I would prefer to get this done as correctly as possible

Find some plumbers pipe thread sealer and use it. Both internal and external threads will need to be clean and dry. Clean with brake cleaner to remove the oil. Let it cure the recommended time (temperature may be a factor) before refilling.
volvolugnut

Mehka01 · Post by **Mehka01** » 07 Jan 2026, 20:17

Many thanks for the replies! I cant see the plugs im referring to having an o ring as its a straight port going to the oil filter internals. No bosses that I saw in there for an o ring to seat to and same situation for the plugs in question.. pipe 'dope' did cross my mind earlier today while waiting for responses but while I was thinking about that.. the tolerances for anaerobic sealant came into mind and given the plug is ferrous (magnetic and more reactive than aluminum) it should adhere very nicely as long as its tight and very hot. I have a very nice heater that will do the trick to help the curing process. Ill repost as an easy solution in case someone else runs into this problem, provided it corrects the issue since everyone will have anaerobic on hand while doing this job (I would hope!!)

Mehka01 · Post by **Mehka01** » 09 Jan 2026, 10:17

Anaerobic sealant did not work. I used a space heater to keep the area around 80 degrees Fahrenheit and gave it nearly 12 hours. Im trying to use blue block now which is a very nice high temp oil resistant pipe dope. It shouldnt need much time to cure but ill give it time anyway

Post by **DavidE7** » 09 Jan 2026, 20:43

I use a razor blade to scrape all the old anaerobic sealant off the aluminium pan and block before applying the new sealant with a touch-up roller from Home Depot. I squirt the new sealant right onto the aluminium from the anaerobic sealant tube and then use the roller to spread it around for a consistent red surface. Here is a picture from right before I reinstalled the Ti S60's oil pan:

I also use a bit of the anaerobic sealant on the two o-rings to hold them in position while installing the oil pan.

The oil pan was also cleaned in an ultrasonic tank to get all the oil and sludge out. The ultrasonic cleaning doesn't remove the old anaerobic sealer - that was all elbow grease with the razor blade.

Post by **DavidE7** » 09 Jan 2026, 20:58

Another potential problem is if the o-rings don't stay in their grooves or if they buckle. I found a buckled o-ring when I pulled the oil pan off the Magic Blue S60:

This is the other o-ring:

If both o-rings don't stay in position while you are installing the pan, there will be a big oil leak. It will leak because the oil pressure is much higher than the strength of the anaerobic sealant. The o-rings are necessary.