I believe that the private label BMW oil in 5W30 is a full synthetic or group IV oil. This is not a good oil choice for cleaning or rinsing for maximum Auto-Rx effectiveness.
The BMW spec that you are referring to has mostly to due with long life oil change, (LL01). In your case instead of running 12,000 to 15,000 miles on an oil change, you will be running 3000 mile oil change intervals. It is my guess that you are equipped with the inline 6 cylinder, 24 valve, fuel injected motor, which is a non turbo. Many folks running this platform have run conventional Castrol GTX for both the clean and rinse phase(s).
With respect to creating oil leaks, the chances here are slim and none. Auto-Rx has no impact on seal materials, other than to clean contaminants off. If your mechanic that replaced your valve cover, last year stated that the top end of the motor looked good, or clean for its age, the question becomes whether or not two cleaning and rinses are necessary or one. Most deposits that have been in place for many miles and years for that matter may take two cleanings. You can be a good judge when examining the filter cartridges from both the cleaning and rinse phases. For example, if your filter cartridge is loaded with contamination after the rinse phase, then a second cleaning and rinse is surely warranted.
With respect to your 4 speed automatic trans: There must be a way a fill plug or whatever to add transmission fluid, in lieu of the absent dip stick tube. I will reseach this a bit further if needed. But back to the question of leaving 4 to 5 quarts of ATF behind in the torgue convertor by a simple pan drain, it is not a huge issue. By installing 6 fluid ounces of ARX total into the transmission sump, over the course of driving 1000 miles deposits within the convertor will be dissolved and now suspended in the trans fluid. So in actuality by a simple pan drain you will get most of the contamination out. You may want to re-dump the pan again in 1000 miles again so that an even higher percentage of the fluid has been exchanged.
Servicing automatic transmissions without a dipstick does require a review of the proper "vehicle specific" procedures before starting.
On a Passat the procedure is to elevate and level the vehicle so that you can get underneath it. There is a drain plug and a fill plug on the drain pan. If you were just to add ARX or additional ATF you would want to start the procedure when the transmission is cold.
Start the engine then remove the fill hole plug. To get fluids into the transmission I use a wide mouth funnel attached to several feet of clear tubing. The end of the tubing may need to be reduced in size at the fill point. It would help if you had someone assisting with this project but if you want to do it by yourself you need to devise something that will keep the funnel upright while you are checking for overflow under the car. Have another container ready to catch any overflowing fluid.
After the transmission has reached a certain operating temperature the fluid will expand. Continue to add fluid until it overflows. Then quickly cap off the fill plug.
To service the transmission later you will probably want to drop the pan so that you can change the filter. At that point know about how much fluid the transmission requires. As you get close to the maximum amount shift the transmission into each gear to be sure that fluid is getting into all areas of the transmission. Place the transmission back into park and wait for it to come up to a designated temperature. Continue filling until it overflows then cap off the fill plug.
If you were to try and add fluid without the engine running you would find that a large quantity of ATF would flow out when you removed the fill plug, leaving you low on fluid. Always have on hand a little more ATF than you think you will need for the project. Some have reported that their transmissions were overfilled from the factory and some were underfilled. Don't assume that the amount that drains out is the correct amount needed to go back in.
-- Edited by TurboJim on Monday 22nd of February 2010 12:45:24 PM
Pretty clean, leaves a lot of room for interpretation. So you must as yourself, is my current maintenance schedule effective in the long haul. Valve train, crank bearings, cam bearings, nor piston ring deposits form overnight. They build gradually until they become a problem. There are other things that can bring on faster onset of large amounts of lubrication contamination. Such as the motor over heated due to a ruptured coolant hose. Or the crankcase ventilation system was fouled for the last 10,000 miles. Or the thermostat was stuck open and the motor ran rich for the last OCI. These types of things can dirty up the oiling system pretty fast. Or perhaps you have had no of these things occur, yet the maintenance schedule has been run beyond the useful life of the oil by 1500 or 2000 miles over the last 10 years. May be the piston rings are not sealing quite as well due to coked up oil deposits, thereby allowing more unburned fuel entering the crankcase.
You can add the auto-rx to your current oil on the back end of the OCI or oil change interval, with your current BMW full synthetic. If you choose to do so I would run the ARX in this oil for 3500 miles. Auto-Rx is not as effective when combined with PAO oils that contain a high dose of polar esters that allow additives to stay in suspension. Polar ingredients have an attraction to metal surfaces. Therefore the cleaning ester in Auto-Rx must compete for the metal surfaces, with the coupling esters of the full synthetic oil.
This is why we also recommend that mineral oil, conventional, or group III synthetics be run during the rinsing phase. Non polar oils rinse contaminants off the metal better than polar ingredients that are attracted to the metal. So if you do choose to run ARX with your BMW full synthetic, I would suggest upping the mileage to 3500. Then run a short burst OCI of a conventional or group III oil to rinse. This is for best results.
Transmission deposits are much different than motor deposits. This is mainly due to the fact that it basically a closed system. The fluid is degraded by heat, some oxidation, and metal wear. You are not getting all of the air ingestion, unburned fuel, and so forth into the mix. Doing the pan drop, I would do two exchanges after running the ARX dose and call it done.
