Re: Tried and True Sludge Removal?

The 318 was a very good engine, Steve. I probably didn't have to tell you that.

Make sure the PCV system is working, and change the oil and filter frequently. I use

2000 mile intervals.

In my case, I was not pleased with my old favorite Quaker State oil anymore (and have never liked Pennzoil) because I saw beginnings of varnish and sludginess so I changed brands. It is too early to tell, but I think my new choice is better.

Before I made the change, I ran my vehicle about 200 miles with a half pint of Marvel Oil in the crankcase. I did not do a detailed inspection (did not remove valve covers, etc) after this change, but from the dipstick and filler cap, it appeared to help clean up.

I would not even consider synthetics for your car.

check auto-rx.com

Personally, I think removing the sludge chemically may well cause more harm than good. The only right way to remove sludge is to tear down the engine. And, sludge typically doesn't cause any problem unless it gets really bad and clogs up an oil passage or some such. If it was my car, I'd use a good conventional oil and change the oil and filter every

2,000 miles for say 10,000 miles. Then I'd switch to Mobil 1 and change the oil and filter after about 1,000 miles than then increase the mileage between changes by 1,000 miles until I reached 5,000 mile intervals. I'd then keep changing at that interval and using Mobil 1 and drive that baby, unless you don't drive enough to accumulat 5,000 miles in 6 months time at which point I'd change the oil every 6 months regardless of the mileage.

Matt

Why not?

Matt

Do not use any aggressive chemicals, especially those 10-minute flushes, which are known for clogging up oil passages and making pistons leak much more than before. The safest solution is, as people have suggested, frequent oil and filter changes, but if you try transmission fluid (no more than 1 quart), remove it in 100 miles (drain oil, change filter) and remove it again 100 miles later or the engine will wear out prematurely. Never use bargain basement-quality oil, only SJ or SL rated oil, not even for those 100-mile changes.

Check the PCV system because a clogged valve or leaky hose can increase sludge a lot.

I wouldn't go synthetic, as I mentioned earlier. This car is nearly 15 years old. The clearances cannot be as tight as they once were, the gaskets not as flexible, nor the engine as clean.

At this stage you have nothing to gain in terms of wear protection from this type of oil. No reason to waste money on an engine that doesn't need it, and might actually suffer from it.

So? Synthetics have no more need for tight clearances or flexible gaskets that other auto oils.

Wear protection is the least of the reasons I use synthetic. I use it mainly for cold weather cranking and faster oil pressure rise as I live in the northeast. If I lived in a hot climate, I'd use it for its resistance to break-down from high heat.

Whether the engine needs it or not depends on a lot of factors, climate being one. It is easy to argue that no engine NEEDS synthetic. I think it has benefits so I use it. I don't know of any engine that will suffer from synthetic. You are repeating old wives' tales here.

Matt

I wholeheartedly back Ted's recommendation. Don't put ANYTHING except oil in the crankcase. Use a top quality oil (Castrol GTX conventional, Mobil 1 synthetic, etc. -see bobistheoilguy.com for ones that are currently giving the best results in oil analyses) and do short-interval changes for 10-15k miles. Change the filter at EVERY oil change, and if you're paranoid change the filter and add a quart of fresh oil halfway between changes.

So? I currently use synthetic oil (Mobil 1) in an engine with 430,000 milles, one with 207,000 miles, and one with 150,000 miles. The claim that synthetic oil will cause leaks like a sieve is just a myth. IMO, whether you want to spend for it depends on how long FROM NOW ON you plan to keep the car, not how old the car is or how many miles are on it. But also be aware that there are conventional oils now turning in metal numbers nearly as good as synthetics, and synthetic blends are also a possibility.

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Steve, I hear you and Matthew.

I don't necessarily accept what you say, however.

There are old wives tales abounding, true enough. You pay your money and take your chances.

Well, nobody says you have to accept it. Steve and I will continue to enjoy the many benefits of synthetic and you will not. No problems! :-)

Matt

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")

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