Tried and True Sludge Removal?

If you're going to quote old southern sayings, at least quote them correctly. 8^)

The proper quote is: "You pays your money and you takes your chances" - has more of an attitude, with racial overtones. My grandmother was from Atlanta, and used to say that all the time in the not-so-p.c. days.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

I dunno, Bill, but that phrase is still in somewhat common usage around here (not everyday, but you still hear it) and nobody takes it as any sort of racial comment. Why would you? The Eubonics factor?

--Geoff

I'm curious - do you hear it exactly like I quoted it, or do you hear it grammatically cleaned up? The way I quoted it was a stereotypical way of characterizing certain people in that time and place (if you ever heard Uncle Remus and Amos and Andy, etc.), kind of ingrained in the culture. The fact that it is still quoted with the grammatical errors intact may be lost on people today (i.e., they don't realize the origins of the grammar).

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Exactly like you quoted it, you pays your money and you takes your chances.

--Geoff

Just make sure you do a gentle/slow (not rapid) flush before switching over to a synthetic on a high mileage engine. The bit about synthetics quickly breaking loose old deposits is not an old wives' tale. Ask me how I know. 8^)

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

How do you know? At what mileage did you switch? The highest mileage car I ever switched had 50,000 on it and I had zero problems.

Matt

Absolutely - there are variables. You might take a look at this 300M ezBoard thread that started out to be about blends, but also became a discussion on potential problems and precautions of switching to synth at high mileage:

see my second post in that thread. IMO, 50k miles would be very low risk for a sudden change to synthetic except in the extreme end of the bell curve (i.e., an engine that is prone to sludging up, such as the 2.7L Chrysler and certain Honda and Toyota engines, probably others, that has had poor maintenance, like oil changes at 15k miles, and mostly stop and go short-trip driving).

For a typical engine in which the maintenance and driving history is unknown, I would say do a gentle MMO or Sea Foam cleanout for anything over 40k miles to be on the safe side (for an engine that is known to have sludge problems, I would do it regardless of the mileage - unless it's 10k or something like that). If I knew the engine had been maintained properly, then anything over 60k miles would get an initial cleanout. If over 110k miles, it would get a more extended cleanout - maybe 3 or 4 short interval changes. Filter changed with oil in all cases.

Can I prove any of the above? No. Just gut feelings formed over 35 years of driving and DIY maintenance and one bad experience in which I did a sudden changeover to synth at 180k miles with a successful non-invassive recovery switching back to non-synth with MMO, and using MMO on every car that I've bought since (initially and thereafter as a preventative).

Could someone take a 200k mile engine and suddenly switch over and never have a problem? Absolutley. I know it's been done. But as you said, "How do you know?". The answer is, you don't, so you take precautions using some common sense (and letting any pertinent knowledge you have about the particular vehicle affect the decision).

BTW - that 180k Mile changeover vehicle was a turbo'd '86 Subaru wagon. Sold it last year at 275k miles with original engine and original turbo still running great. The guy who bought it e-mailed me two weeks ago to tell me the frame had collapsed (cancer), but he saved the engine to transplant as-is to another vehicle. One amazing engine!

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

I've heard the tales about synthetic magically removing sludge, but I've never heard it from what I consider to be an "official" source such as an engine maker, oil maker, independent oil testing lab, etc. I've only heard it in the form of anecdotes from individuals. No offense intended, but that is also the source of every other old wives tale and urban legend so I place very little credibility on such information.

I know that synthetics are supposed to cause less sludge formation, and I think that is true, but I don't even have any hard evidence of that. What little I can see of my engines, and from the Honda I had which required 15K mile valve adjustments so I had to pull the valve cover periodically, I seem to get less sludge than I did 25 years ago before I started using Mobil 1. However, it could also be that modern engines are less prone to sludge formation and what I'm seeing MAY not be the oil at all, but better engine technology. Without running a controlled experiment, there is just no way to know such things. I'd love to have the resources to run such a test, but it would cost lots of $$ and take many years with many vehicles.

And even if it is true that synthetics cause less sludge formation, it doesn't necessarily follow that they have a greater solvent action to remove existing sludge. I know of at least one situation where synthetics caused a LOT more sludge, and that was aircraft engines using high-lead content gasoline. This is well documented and was admitted to by Mobil who subsequently pulled their aviation synthetic oil from the market. So even though synthetics are better than conventional oil in almost every way (except price!), they aren't necessarily better at everything.

I personally like Mobil 1 and have used it since about 1979, but I'll admit to being at a loss for much hard evidence on many of its performance parameters. I use it mainly for the winters we have where I live, and I do know that the difference in cold cranking is very noticeable, especially below zero. Above 32, the advantage isn't noticeable compared to a conventional 5W30, but at -20, the difference is dramatic.

Matt

I've switched several cars at over 100,000 miles, one of them at over

200,000. Zero problems. They were using very good conventional oils before hand and were in great shape (or I certainly wouldn't have switched them anyway!) I wouldn't recommend switching a car that's been running the cheapest oil you can buy for 80,000 miles without being careful, but I'd do it. I'd just change the filter and oil every 1000 miles for about 3 changes, then increase to a more normal interval.

No, its very DEFINITELY the oil that has changed. Much more than engine tech. I've run several old engines (66, 69, 73) with both synthetic and modern conventional oils and had absolutely none of the deposit formation that I used to see years ago in these same engines. I wouldn't call it "sludge" because I didn't get sludge in my engines 25 years ago because I was always picky about running the best oil I could find, but even then there used to be a dark sort of non-sticky, non-flaky varnish that would build up which I do not see in the same engines with modern oils. The last time I had a valve cover off my '69 440, I was frankly shocked that the metal wasn't the typical amber color I used to see, but still bright silver.

The much bigger problem was that most synthetics weren't suitable for use with silver-containing bearings commonly found in A/C engines.

My Honda had a light honey color on the valve cover even though I ran Mobil 1 in it from 5,000 miles onward. However, it was a very thin layer and could be wiped off with your finger. Nothing even close to sludge.

However, even Mobil 1 couldn't keep the cam and rocker arms from self destructing at less than 80,000 miles...

The engines that failed with Mobil synthetic aviation oil failed from sludge build-up long before the bearings failed. As I recall, the typical failure mode was the prop governor, or feather control in a twin, would stop working properly due to clogged oil passages. I don't recall of hearing about any issue with bearings.

Matt

Like I said, no surprise. Different engines have different sensitivities.

The Subaru engines (EA82 variety) are prone to lifter clatter due to very small oil ports in the lifters (technically "lash adjusters"). Also, they have pressure relief valves - one in each head - that regulate pressure up in the valve train area. Also, keep in mind that the oil pressure at idle on those engines drops pretty close to zero at normal operating temperatures.

Within a few days of suddenly switching over to synthetic, the lifters started clattering (the oil had been changed religiously using Castrol, which I consider a quality oil). I switched back to non-synthetic and, over a period of months, I was able to get rid of the clatter by using MMO in the oil and changing the oil and filter relatively frequently. My theory is that some crud got into the lifter ports or in the pressure relief valves, and had to work its way out. This scenario, with minor variations, was repeated by several others on Subaru forums.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

If you theory about synthetic dissolving sludge is correct, wouldn't it have been better to just leave the synthetic in until the ports were cleared rather than switch back to conventional oil? I believe that MMO is as much solvent as oil, so I don't see how adding that to conventional oil is any different than using synthetic, assuming synthetic really has a solvent effect. I'm not convinced it does, but then I don't know that it doesn't either.

Matt

Matt

Mainly a problem with older aircraft engines- big radials especially. Silver bearings would be toast in a matter of HOURS with some oils. Not because of the base oil, but because of the additive package. I think it sorta soured the whole aviation community on synthetics, though. And given the fact that no one in their right mind would do "extended drain intervals" on an aircraft engine, and engine life is set not by wear but by required overhauls based on accumulated hours, synthetics really don't have an advantage.

The hope would be that the synthetic would not have had time to do a complete disolution of the sludge, and cleanout at a slower controlled rate could be achieved.

According to my theory, 1/8 to 1/4 qt. of MMO diluted with 4 to 5 quarts of conventional oil is not nearly as solvent as straight synthetic. In preparing for a switchover to synthetic, the idea is to do a gradual cleanout at a rate that the lubrication system can handle. This can be accomplished with the diluted MMO, or by doing a couple of changes with, say, 1 qt. synth to 4 qts. conventional, which is another method that many people recommend.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

All of the sludge problems I read about affected the horizontally opposed Conti's and Lyc's. I don't recall reading anything about radials.

Matt

yeah high detergent oils like Super-D III Kendall will wash it out but you run the risk of plugging an oil galley. use a good quality oil and change it alot.

I'd stay away from quacker hack and pennzoil.

yeah high detergent oils like Super-D III Kendall will wash it out but you run the risk of plugging an oil galley. use a good quality oil and change it alot.

I'd stay away from quacker hack and pennzoil.

Why stay away from Pennzoil??

The oil analyses & reports from bobistheoilguy.com forum show Pennzoil to be an excellent oil.

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