CHANGING OIL TOO OFTEN???

Just got back from the Porsche dealer after taking my 2002 C2 in for its last item before the warranty runs out. My complaint was a possible RMS, as well as, the vehicle consumes oil at the rate of 1 qt. of Mobile 0-40wt per 500-600 miles. The vehicle now has 28,500 miles on it. Since I've owned it, which is only 2 1/2 months, it has used oil at the rate of 1 qt. per 500-600 miles. I have put 2500 miles on the car since the purchase. The last oil change was at 25,200 miles. The veteran certified Porsche mechanic found that the seal has a very slight weep and ordered the parts to replace it. He asked me how often the oil was changed in the car, for which I knew the answer to be every 5000 miles. His remark was that I should let the oil remain in the car for 10 to 15,000 miles before changing it. His spin on why the car was consuming so much oil, is that the oil was changed way to often, therefore it has never allowed the rings to seat, even with over 28k on it! I've been fooling with cars and aircraft engines for over forty years and have never heard of anything like this. This maybe one stupid question, but has anyone else ever heard of such a thing, and if so, what would be the cause? Or better yet, the cure? Tom L 2002 C2

The mechanic if full of it. Typical Porsche tech. I doubt very much that your oil is being lost because of an RMS leak as you would have a measurable volume of oil on the floor. You are burning it and it is not normal. Make sure you have your orginal complaint in writing so when you find out the new RMS did nothing to stop the oil loss, you have a leg to stand on. However, Porsche's standard reply will be that the car SHOULD burn oil and unfortunately, too many Porsche owners accept it as normal.

My car has 55K miles on it now and I change it every 5K miles and have personally done the oil changes on the car since about 20-25K when I came to this board and learned how to do all the maintenance items (thanks Renntech.org as well!). I burn ZERO oil between oil changes and I drive this sucker like it was meant to be driven. I also track the car quite often and at most have had to add .5 quart between oil changes at the most. What your "mechanic" said is complete crap. Wanna age your engine much quicker than it should be? Then start changing your oil at 15K intervals!

The " veteran certified Porsche mechanic " sounds more like a saleman to sell you a new engine sooner than you need one -- if you change oil ~ 15,000 miles.

The only possible downside to changing oil more often are: 1. extra expense and effort 2. oil may not achieve optimal lubrication -- oil contains many additives, esp those that are used for extended intervals such as most synthetic. Additives don't lubricate, they are mixed in the oil to achieve stability of the oil against breakdown. During first 3-5k mi of the oil, extra additives in the oil actually reduce lubrication. If you change oil every 3-5k mi, you actually aren't getting best lubrication for your car. Regarding #2, I don't know how true it is. I'm just sharing what I've heard. Regardless, your oil loss has little to do with the frequent oil change since break in happens in first thousand miles or so and oil at that time is still new. Oil loss is probly due to cylinder ring seating. A compression test should be done. If it's below spec, you're looking at a new engine most likely. I don't think RMS is your cause of leak esp if it's weeping. Most RMS are found as drips on floor or by inspecting wet spot near engine. You may want to try antoher dealer for a second opinion before warranty run out.

I have heard of a few motorcycle (BMW) that did have high oil consumption with 25,000 miles that was attributed to the synthetic oil lubricating a bit too well preventing the rings from seating. These engines were not specifically desinged for synthetics and were switched to synthetic oil eary in their life. Some of these engines did eventually improve their oil consumption.

Find a good independent mechanic that knows P/cars. This guy simply doesn't know what he's talking about.

A quart of oil every 500 miles is a lot. When you lose oil, it is either from leaks or you are burning it in your engine. If you were losing oil from leaks at that rate, you would see the oil on the garage floor. If you are burning oil, you should be able to see bluish smoke coming from your exhaust pipes.

I am not seeing any smoke from the car. There is no oil on the garage floor. Maybe I'll have my wife drive the car as I follow to see if there is any smoke. I think I will try and get the Porsche dealer to do a compression test next. I have notice one thing since I took my first sustained trip in the car the other day. When I took the car to the dealership which was about 170 mile round trip, I measured the oil when I got back, and it did not show nearly any drop in its level. This is the first time I have gone out on the road at sustained freeway speeds. All my other driving since I got the car has been through canyons at higher rpm settings. I would assume that the higher rpm driving would consume more oil then a simple cruise on the freeway in 6th gear? Tom L 2002 C2

i had three m96 motor cars. oil changed every 3-4k miles. two that i babied, all used oil, not much. but does use oil. the one i drove the wheels off since day one, i never bothered to break it in. took it to track at 600 miles. that one never used oil even on track driving. not leaks and no rms prob. maybe the hard driving created more pressure to help seat the rings better? i don't know.

That seems to be the word on the street John. The cars that seem to leak are those that have poor seating of the seals especially during break-in. This is found in quite often in those low mile garage queens. Not to say it doesn't happen with the high mile cars or ones that have been broken in properly, just that is the trend that has surfaced.

If changing oil too often reduces lubrication, wouldn't that HELP the rings seat (under the theory that too much lubrication will cause them not to)?