An update to the ARX plan in my '97 Taurus.
Over the weekend I finished the 2k mile rinse phase. To give you a recap rather than read all the posts, I used a double dose for 1/2 the recommended mileage, and shortened the rinse phase to 2k miles; this plan was at the bequest of Gary and Frank. The plan was two bottles for 1k miles of application, then 2k miles of rinse phase, using recommended group III (PP) on application and group II (QS) on rinse.
The compression on cylinder 5 was the last lagging, and nagging, concern. While it did respond (coming from 110 psi to 150 psi) after the initial application, it never fully came up to 180 psi where the other five cylinders were restored to after that 1k mile application phase.
At 90k vehicle miles (just finisned rinse) the compression on cylinder #5 is now at 160 psi; it saw a 10 PSI improvement during rinse phase. For reference, the shop manual calls for all cylinders to be within 15 psi. Cylinder 5 is just shy of that; all others are essentially at 180 psi.
Because of the TREMENDOUS improvement in the other cylinders from the previous application, I have decided to do another application of ARX.
My plan this time is to take the "conventional" approach. I have added one bottle of ARX at this OCI of more QS group II in 5w-30, using a Wix 51516 filter. I will run this for 2.5k miles, and then rinse with the same type oil for another 2.5k miles. I had such great success with ARX the first time that I see the opportunity to bring this last cylinder up with the rest. It is not unheard of to need a second application of ARX sometimes in extreme cases; my Taurus certainly qualifies for this as it was grossly overheated before my owning it.
Stan tuned. A word of caution is that it might take me some time to accumlate the next 5k miles. The weather is turning nice (finally), and my Goldwing gets about 38-40mpg, so the Taurus will often sit parked this summer.