Based on your maintenance history of 5000 mile oil changes with Mobil 1, full synthetic you may not have a very dirty motor at all. Most folks that develop sludge run extensive oil change intervals, such as 15,000 miles on synthetic, or 7500 miles on a conventional oil. Of coarse there are other things that can cause sludge, such as a blocked pcv valve or system, overheating the motor due to a coolant problem, engine not running in tune, etc.
In many cases, M1 or other full synthetics, can keep an engine fairly clean. However, in areas such as piston rings, full synthetics can fall far short in keeping them clean. If you are going to develop sludge, it will most likely be from unburned fuel seeping past your piston rings and diluting your lubrication oil. So although you may not have masses of cleaning to be done on the Durango, I am sure that in high heat areas of the motor, like the rings and bearings, you will dissolve some build up of oxidized oil or coked up deposits.
All engines tend to develop ring deposits. Some just take longer. Auto-Rx disrupts these formations. For someone who has used M1 for shorter oil changes, this would probably be the biggest benefit. One treatment between something like 60k-80k would be a good reset on bringing things back into tip top shape.
Naturally this assumes that that the aforementioned items are otherwise functioning well and that there are no design issues of merit that M1 was keeping at bay over that compressed interval (5k).
I want to share about a 99 Dodge Durango that I recently worked on. This guy was previously running one of Amsoil's best oils, their 5W-30 HDD, for 20-25k mile oil changes with a filter change somewhere in the middle. His wife was using this vehicle for a large rural newspaper delivery route up until a year or 2 ago. I told him about Auto-Rx one time when we were talking about his Dodges. Although he had no negative issues with the engine, he decided to give it a go for 2 complete cycles since he had run really long oil change intervals previously. We used non-synthetic oil during both complete treatments, and afterwards he went back to a less expensive synthetic oil.
This engine currently has 225k miles on it and runs and sounds like brand new. Last week he had me do a complete tune-up and change the original valve cover gaskets, not that he had any real leakage, but there was a bit of wetness at the bottom of each after all these years and miles. When I pulled off the cover, we were both amazed at how clean it was in there. Absolutely no accumulated deposits at all. Some of the outside of the rocker arms had some darker brown color to them, but overall, very clean, almost new-looking.
He likes how the Durango runs now much better, even though it never really ran poorly. He said he and she both felt a noticeable improvement after the first treatment was started. Within only a few weeks, the acceleration and smoothness was noticeably better. He did 2 Auto-Rx treatments on his 2001 Ram at the same time and noticed improvements as well. That truck is his current work vehicle and had a similar history of very extended oil changes on the same oil. We had already done the valve cover gaskets and tune-up on that truck before starting the Auto-Rx. It was definitely not as clean inside the valve covers as the Durango, post Auto-Rx, but there was not any sludge either. That engine had about 140k miles back when we opened it up.
After having their 4th child and with only him working outside the home, he felt it was a good idea to do 2 treatments on each truck, especially after running such long oil changes previously. He is trying to avoid having to replace these vehicles as long as he possibly can. He has also had me change all of the powertrain fluids previously at some point, so he may get quite a few more miles out of these vehicles. The only hiccup is they may have to upgrade the size of their vehicle if they have another child.
-- Edited by bmwtechguy on Saturday 5th of June 2010 08:30:43 PM
Yes I agree with geeaea as all engines do tend develop ring deposits and on the oil pump too. I have only found Auto-RX that can slowly, safetly clean it without having the engine stripped apart. Call me lazy if you like!
-- Edited by ForeverFord on Thursday 3rd of June 2010 04:24:56 PM
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1994 Ford Granada Scorpio Cosworth Automatic 2.9i V6 24valves
