2002 S80 Oil Sump R&R, now I have low oil pressure at idle

[crussell83]

I have seen a read many post on this board and others. I have not seen an answer that is working for me. I have figured out how to remove and replace the oil sump somewhat easily. I will post that process in a follow up post.

Questions from below:
1) Should I be able to blow air through the "valve" going between the filter chamber and the sump?
2) What is the purpose of this "valve"?
3) Do I have a spring in my oil pump for pressure relief ( not in my schematic)?
4) If no on #3, then where is the pressure relief spring? If yes, then how do I get part numbers for it?
5) Is Loctite 518 a good choice for sealing the sump to the block?

I have a 2002 S80 T6 w/165K. The square drain for the oil trap drain was 100% blocked when I bought the car. I pulled the oil sump and cleaned it (write up will be listed below as well). I had no indications to any oil pressure issues before I pulled the sump. I now have below allowable oil pressure at idle once the car is warm. Current oil is a 20w50 (not my usual 10w30 synthetic). The dipstick appeared to have a few very small bubbles in the oil on it. The following oil pressures were taken with the engine at 165 degrees to start and was 190 when done.

RPM PSI
650 5 165 Deg.
1500 35
2000 43
3000 58
4000 65
1500 33 190deg.
On cold start up the idle pressure was at the least, OK.

I have pulled the sump off and I would like some advice on the "valve" part # 463963 #19 in the Lubricating System Part Schematic. This screws into the sump and goes between the oil filter chamber and the sump itself. I can blow air through it without using any force at all. 1) Is this normal? Neither of the two local dealers carry this in normal stock and do not remember ever selling one. Also, 2) can anyone explain what the purpose of this part is? It looks too small to be an oil pressure relief valve. I will special order it tomorrow and see how the new one acts.

I have read where the pressure relief spring in the oil pump can go bad. The schematic for this engine does not show any springs in the oil pump. 3) Should my oil pump have one in there? 4) If not, where did the move the oil relief valve to? If yes, then how do I get part numbers for it?

It does not appear that I mis-installed any of the O-rings, or any other signs of an issue on my part. I currently have the sump removed. I used Loctite 518 to seal the sump to the block. 5) Does anyone have any input good or bad to this?

Thank you for any insight or help!

[crussell83]

Removing an oil pan on a 2002 S80 T6, without a floor lift:

I have read and used both VIDA and an online Chilton's site. There may be a reason, bit VIDA adds a lot more steps and completely removes the subframe.

Raise the car and place a jack stand under each of the rear sub frame mounting plates (picture below).
Place a third jack stand (with wood block to spread out the weight) under the transmission pan. You want to center this and double check it as this will take all of the weight of the transmission and engine.

Remove the:
dipstick tube
lower engine cover
front air baffle
oil and oil filter
front wheels & lower ball joints
release the axle shafts from the hub/spindles ( not sure I really needed to do this)
remove front engine mount and transmission mount from the subframe
trans ground strap, power steering hose, air duct, wire harness bolt (there are about 4-5 bolts on the front of the subframe hold items like those above to it).
rear engine mount bolt (1)
steering gear bolts to subframe (4)
EVAC and fuel line from the side of the subframe.
right engine mount bolts to subframe (2-17mm)
Place a jack stand (#4) under the front of the subframe.
remove the subframe bolts (4)-do not remove the 2 bolts on the rear subframe mounts.

You should now be able to put a jack under the front of the subframe and start to lower it. Be careful as you may not have disconnected everything. Lower slowly and double check.
The rear mounts never come out and act like a pivot for the subframe. You want the front of the subframe to drop about 10-12 inches. This allows plenty of space to remove and replace the oil sump.

Installation is just the reverse. You can lift up the front of the subframe and reinstall the front bolts.
I can now have the oil sump out of my S80 in about 90 minutes.

Rear subframe mounts jack stand:

Subframe drop:

Original reason for this:

Hope this is useful,