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Adding second drain plug?

4K views 27 replies 10 participants last post by  DRMCEO 
#1 ·
I have the tray down and of course my 06 does not have the forward drain plug. There is a TIS on ensuring a minimum level in the forward sump. Did some searching and didn't find anything about adding a plug. I'm tempted to be the first but I would hate to drill into the oil pick up. Anyone done this?
 
#7 ·
Well I found a few pictures and have an idea of how much material there is and what I might hit drilling through. I'm thinking a 1/8" pipe plug or a small machine screw. My biggest worry is hitting the oil pick up tube, not the end of the world but it looks like either a screen on the newer style or just a whole on the older style pump. The newer version pan has the plug off to the side with added material for the plug. That does not inspire confidence either.

So the question, is the risk of something going wrong worth the benefit of draining the extra oil. BMW saw fit to add it to later models some there must be a good reason for them to retool the change. The pump just transfers the forward sump to the aft sump.
 
#10 ·
Well cooler heads prevailed. Based on the operation of the forward sump, the total volume of oil I just don't see the need. Just for fun I pulled the bumper cover and oil cooler. I think I found a good place for the accumulator. Some guys massage their leather an some guys wax their paint, I am not some guy.
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#12 ·
So for now I'm leaving the second drain plug off the table, it just isn't worth the risk without the pan off. So the real reason I started all of the work is the rear diff input shaft seal.

So now I have the exhaust down and I'm thinking about removing the cat material from the headers. I have Meisterschaft GT mufflers so the car is pretty loud already. Based on my research I can leave the secondary cat and resonator alone and still get improved flow. Any other big warnings that I may be missing?

Another item I'm looking at is the SMG motor clean up. I can see the reservoir, motor and accumulator. The job looks pretty decent and I'm right there. The o-rings may be tricky to get but I have an email to Jim to see if he has them.

Finally I did get the transmission fluid changed. I pulled the screen and there was maybe one or two specs of dirt on it. Redline MTL in and that box is checked.
 
#15 ·
Another item I'm looking at is the SMG motor clean up. I can see the reservoir, motor and accumulator. The job looks pretty decent and I'm right there. The o-rings may be tricky to get but I have an email to Jim to see if he has them.
Assuming you took the driveshaft out then yes you are 6 bolts away from dropping the trans cross member. Once there you can access everything on the hyd block. Do the motor brush fix, change clutch valve orings and all other pump and reservoir orings. The pump internal oring is optional assuming you want to spend that much (>$100 for an ebay oring - no thanks). I know Jim's been having email issues, try calling or FB if you don't get an answer.

Finally I did get the transmission fluid changed. I pulled the screen and there was maybe one or two specs of dirt on it. Redline MTL in and that box is checked.
Did you run the cooler pump for a minute to drain everything out / and ran again to refill the cooler?

Another question is has anyone taken apart the oil filter housing and removed or changed the thermostat? I'm pretty sure the oil will still warm up with the car sitting and when I'm on the track I want as much cooling as possible.
Sure you can but... why? No thermostat means you run cold oil longer. Unless your thermostat is restricted in some way why would you get more cooling? Want more cooling get the radtec cooler.
 
#13 ·
I almost forgot. I'm looking at the pan and there are small pumps on both sides. I think they are the pumps that pump the oil down from the heads during heavy cornering. I'm thinking about a prelube pump and was wonder if one of these can be used?

Another question is has anyone taken apart the oil filter housing and removed or changed the thermostat? I'm pretty sure the oil will still warm up with the car sitting and when I'm on the track I want as much cooling as possible.
 
#14 ·
I have a late 07 Troy-built motor and he added the 2nd drain similar to the above. I just had to drill an access hole through the bottom panel and use Fumotos on both drains now so I don't have to mess with those stuipd allen drain plugs anymore. Well worth the money.
 
#16 ·
I just finished completing a rod bearing job myself. I added a second drain plug to my '07. I bought this bung off of Amazon: https://www.amazon.com/gp/product/B07D1CLJXN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It has the same threads as the factory drain plug. I had it welded and cut shorter, so it didn't extend into the pan at all. If you look inside the pan at this low point, the factory mills the bottom flat to make sure nothing blocks the oil pick. Because of this, I was very careful to make sure I didn't block this in any way.
 
#17 ·
I did not run the pump but I did disconnect the cooler lines and drain the cooler. It appears that the pump and cooler are flooded but I will run the pump when the rest of the work is done. Does anyone know of a place to get the o-rings for the SMG motor service? I have the sizes but it would be nice to have a kit.

As far as the oil thermostat goes I'm on the fence. For my purposes the cooler the better and maybe is general. The oil with the rotation of the crank creates a dynamic wedge that is larger or smaller based on the viscosity of the oil. No flow or pressure is required for this effect. That is how an oil bath bering works. So we add flow to aid in cooling the bearing and the oil delivered to it. This is measured with pressure which does not measure flow but is an easier more reliable way to confirm flow. The high end for most engine oils is 350f, normally it is left to the coolant to control the oil temperature. In this case BMW has added and oil cooler and a thermostat. The risk of oil on the low side is that it will not flow. That is not being controlled and if it were a risk you would add sump heating.

I'm not really sure there would be any benefit to removing the thermostat, I was just wondering if anyone had. I defined benefit would be a prelube pump or accumulator. The oil would be delivered to the berings ensuring as soon as rotation starts the dynamic wedge would develop immediately. Does anyone know which line is the outlet to the engine? The cooler goes in an out of the filter. If I knew which line feed the engine I could tap into that line with the pump.
 
#18 ·
I got my clutch valve orings from Jim. He can provide the motor&reservoir ones as well. Burkhart is another supplier although on the other side of the pond. That's it other than buying them individually yourself.

Going from memory, running the smg cooler pump will get about an extra half cup oil out. The official instructions call for running the pump before and after, check newtis.

Have you seen the M5 training PDF on the sticky? An oil flow diagram might be in there. Check realoem as well see if you can figure it out. If I were to hack into the oil supply lines I'd be worried about a rupture or leaking line which could be catastrophic IMO. That and making sure your in-line pump does not restrict oil flow. Not that it can't be done, but it's all about how it's implemented.
 
#20 ·
JIm got back to me, o-rings are on the way. I have read the flow diagram but it has been awhile. As far as a failure it would be no different than the hoses already going to the cooler. The captured o-ring fittings are great for assembly but suck in the real world.
 
#21 ·
So I read through the M5 service directions. The pumps on either side of the pan will pump the oil out of the heads when G forces are over .8. Unfortunately it appears they are plumed internally. The main oil pump is variable displacement(over engineered) vane pump. using the cooler lines would mean the the pump would have too allow a certain amount of bypass. At 113k on the clock it is possible. An accumulator would work for sure. It would only require a single tee connection and there is plenty of room behind the front reinforcement. The cost is about 5x higher than a pump though. Maybe I'll try a pump and if that doesn't work I can switch to an accumulator.
 
#27 ·
Well I got it all done and back together. Rear diff input shaft seal, rear diff oil change(redline shock proof), Trans oil change(redline MTL), Engine oil and filter change, SMG motor clean and oil change and decat the headers. The car sounds about the same but I added a little red. The screen in the front should improve air flow and keep the bigger bits out. I'm going to stew on the accumulator for awhile and work on my E38 and AMX.
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