Originally Posted By: demarpaint
Originally Posted By: ronrackley
I'd be careful with that MMO in there. From your description of the degree of the sludge problem, I'd change it and the filter again with MMO in a week or two - or at no more than 500 miles while listening closely to the engine to make sure no knocks develop. If new sounds develop, I'd change it immediately. My concern would be clogging up the filter with the products of dissolved sludge and letting junk bypass it to cause restrictions in the oil passages and/or valve lifters of the engine.
I've used MMO and recommended it be used to resolve sludge problems such as cause lifter noise many times over the past 40 years and I believe in it. It may not help much with sludge in the filler tube, where it does not circulate, but it will be cleaning where oil does circulate. From what you say, I'd check the PVC system for a bad PCV valve or blockages in hoses/tubes.
Good suggestions. The internals of that engine are probably a real mess. I would run that MMO for about 500-750 miles max, and dump the oil and filter. If not at least drop the filter and top it off. Then I would run a qt of MMO for about 1500-2000 miles and do another OC. It might take 2-3 runs with the MMO to clean that mess up, but my bet is it will do it.
I would be interested in seeing if it cleans the fill tube, I have my doubts about that.
I am surprised that there has been no discussion of the PCV system, as a non-functioning one can greatly contribute to sludge formation and, even if this one was not part of the problem from the beginning, it is likely to be compromised now from the description of the sludge in the fill tube. To clean that engine up and keep it clean, a well functioning PCV system will be essential in my opinion.
To get to the subject that seems near to everyone's heart - I stopped using Jiffy Lube when they tried to sell me a transmission flush by showing a white card with a smear of ATF on it while an oil change was underway and saying it was getting dark and could lead to an expensive transmission repair if I didn't have it serviced then and there. The car was a Buick with about 45,000 miles on it, but they didn't realize that the transmission had been replaced the previous week under warranty. I told the young man that and asked if he was telling me that the dealer put in a new transmission and then filled it with bad ATF. He leaned over and spoke with the fellow in the pit under the car and then said "it's OK sir." I have never set foot in another one. That was over 20 years ago and I had always been satisfied with their oil changes before that.
