Auto-Rx in BMW E46 2.5 litre engine.

[sprintman]

Anybody used RX in an E46 2.5? What oil did you use? Good/bad? Let me know...s

 

[Craig in Canada]

Same M52 engine, different stroke:
link


Bottom line: if you're doing this in warm weather a good 15W40 HDEO will work well and still supply good HTHS and 40-ish weight these M52 engines like. Rotella should be inexpensive and easy for you to find. If you aren't doing it in warm weather, you might need to be a bit more selective, like GTX 10W40 which I used in an M62 540 which started treatment in late winter in Canada. There are several great UOAs posted from people running full OCIs with GTX 10W40 in our vintage BMWs.

This is also currently being discussed in another two threads or so here already.

 

[sprintman]

Comiing in to winter. I think I need a dino or Grp III 5W40 with zero PAO or ester?

 

[bmwtechguy]

I ran (mostly group III) 5w30 Valvoline Synpower for winter. I may have mixed in one quart of 20W-50 for the summer rinse. 5K miles each run. Previous owner did 15K+ mile oil changes and I was concerned the engine had some deposits. Now on the maintenance dose of 3.5 oz. (.5 oz per quart). Used the Synpower and still using it due to BOGO prices. They did not have any 5W-40 for the BOGO, so I make my own approximate 5W-40 by mixing in varying amounts of 20W-50, esp in summer.

I would not hesitate to use 15w40 HDEO for any spring/summer/fall ARX runs.

I would be more concerned about any ester content than PAO. Here in the states, RTS 5W-40 would be a good one if you just had to use synthetic. I understand it is mostly GIII.

 

[02Pilot]

I'm doing my clean phase now with Havoline 5w30. Depending on the timing of the change leading to the rinse phase, I may go to Delo or Rotella 15w40 if the weather is warm enough. Once I'm done normal fill with be Rotella Synthetic 5w40.

 

[Craig in Canada]

sprintman:

"Winter" is a relative term. I didn't think it really got cold anywhere in Australia in winter. What temperatures do you normally see in your area?

 

[sprintman]

-12C if I go for a drive to the Snowy Mountains 2 hours from here. Maybe -7c here in Canberra but -2c to -4c average winter o'night

 

[Craig in Canada]

Originally Posted By: sprintman
-12C if I go for a drive to the Snowy Mountains 2 hours from here. Maybe -7c here in Canberra but -2c to -4c average winter o'night


OK, let's ask this another way... What's your average engine start condition. Even if it's -2, if your car is always in the garage and it is 10C inside, 10C is your average start condition.

If you keep the car outside, a 10W should be fine since you're only using it for an ARX cycle, but I have to say I'd be tempted to use a 5W30 instead just for peace of mind. Of course if you look at specs, even a full 15W40 is probably just fine around the freezing mark...

The temperature you're driving through doesn't matter, all that matters is the typical engine cold start temp.

 

[sprintman]

Always inside a car port which should be same temp as outside unless I'm mistaken? Winter start average in the morning lets say -2C and afternoon start 7C.