I bought a used 2003 BMW Z4 Roadster (E85 engine) about seven month ago that had 47K miles on it.
Since then, I have changed engine oil, Tranny fluid, rear diff oil (all Amzoil) and flushed and replaced the brake fluid, since I really did not know the how well the car was kept.
Last weekend, I pulled the Valve Cover off, to do the Vanos O-Ring fix. I did not see any real heavy build up of gunk. Just varnish and such, but that does not mean there is not any down deep in the crankcase.
I just received two bottles of Auto-Rx and I am going to add one to the Z4. I have 5K miles on the engine oil (52K now) and was not going to change it for another 3-5K.
My plan is to add a bottle and run for about 2k miles then change the oil filter. My filter is actually a cartridge located on top of the engine and is REALLY easyto get to and pull the filter cartridge out.
I figure I can pull the cartridge out and inspect it, then replace it with a new one and if everything looks good, keep the oil in for another 2k.
OR, I could change the oil at that time.It is not a big hassle and the cost is small for the peace of mind.I drive the car hard and 7000 rpm happens a lot.
Comments on this plan? Or should I modify it?
After the Z, my 97 F-150 w/170K miles will be next.It has had nothing but Amzoil in it since the first 5k mile oil change in June of 96.
Sounds like a good plan. I think that I would consider a dino oil rinse for 3000 miles, after the cleaning phase. The dino should help rinse the internal parts better than a a group IV synthetic, that tends to cling on metal surfaces. I would expect that you should motitor the filter during the rinsing phase. Perhaps should consider running the maintainance dose after your cleaning application is done.