sludge symptoms?

Try looking in the oil fill hole, taking off the valve cover is best. Sludge forms running a cold motor, never alowing it to run at full temp long, such as 1-5 mile trips in winter. Changing oil by driving style, having a good thermostat, longer operating times a working clean Pvc system and good oil should keep sludge away. I think removing it can do more harm as chemicaly flushing it could move it into blocking small passages. Short 1-5 mile winter trips may reduce change intervals to

1000 miles. 5-6000 intervals are for highway trips or good driving where the motor operates warm for most of the time. But winter is hardest on oil.

snipped-for-privacy@yahoo.com asked:

1) Short of disassembling the engine, how would you know if your engine had sludge? What are the symptoms? and also asked: 2) If you do have a moderate amount of sludge in the engine, how could it be removed? ================================== 1) The best way to examine sludge is engine disassembly - but you only have to remove one valve cover. Would guess the next best proxy would be to examine the oil condition. Does your oil go completely black on the dipstick over time, when checked cold, or is there a portion of darker oil near the bottom and lighter color near the top? Sludge occurs when the oil can no longer hold contaminants in suspension, but there aren't any progressive symptoms that are noticeable in the way the engine runs.

2) See auto-rx.com Changing the oil several times at short mileage intervals may also help. Solvents which loosen contaminants too quickly can clog small passageways and are generally not recommended, though people always seem to say good things about Seafoam.

There is no need to disassemble the entire engine. Just take off the valve covers for the sludge symptoms relating to Toyota engines. The problem is elevated combustion temperatures needed for the cleaner EPA certification (ULEV) and that oxidize/vaporize oil in the cylinder heads and overwhelm the PCV system. Pre 97 engines (LEV) run cooler and won't do that.

Modern oils are detergent oils. Try> Short of disassembling the engine, how would you know if your engine

And a sludged engine will... do what, exactly? Give worse fuel economy? Be more difficult to start? Stall more often? Fail smog checks?

A sludged motor wil eventualy stop oil flow to critical areas by clogging oil channels, and fail. I had a motor so badly sludged all the oil would pool under the valve cover because the returns were sludged shut and the oil light came on showing no oil. I removed the covers and opened the holes while removing pounds of sludge. This previous owner obviously never changed the oil. Sludge is like thick mud.

Sudden catastrophic engine failure if the sludge is heavy and a chunk floats under the oil-pump pickup screen.

Jason

It sounds like the owner wouldn't know what hit him until it's too late. Is this the case? No clue at all - from RPMs, or a sluggish engine...?

What happens typically,..if the sludge build-up suddenly dettaches in a critical area such as the main oil-feed driiling to the engine's main bearings and bigends (conrods) and blocks or reduces flow enough, the engine will start starving for lubrication at the main bearings and rod-bearings. The oil-pressure gauge will keep reading normally has it is downstream from the blockage, The driver ten has less than about 5 seconds to shutdown the engine to avoid significant damage. If he's on a freeway, he may not register with him whats going on before the engine crank is toast.

If the sump has enough sludge to partially or wholey block off the oil-pump pickup,..then the driver will get an oil-pressure icon light up on dash. He may, as a result save the engine by shutting it down quick enough,..but from most of the engine failure reports due neglected maintenance, the engine is still fried.

In mine which had a layer of tarry crap on the head looking thru the oi-filler hole, they had removed the sunp to clean it out. I understand this is mandatory amongst mechanics who come ecross abused engines.

Once oil-pressure is lost,..the engine will start belting itself to pieces, especially if under high load (towing, cruising at speed etc)

Jason

We followed the recommended schedule of service every 5k miles at our local Lexus dealer on an 01 RX300 and still had a sludge problem at 30k miles. You probably need to change more often. Got rid of the car almost immediately. Per the dealer, the Lexus solution to problem engines was to find a used engine in a junkyard.

Sludge can be reduced by using Synthetic oil and be sure your thermostat is good, A cold motor is a main cause of sludge. Oil condition by visual inspection is a better indicator than miles. Type of driving city vs Hwy is most important as in city driving in cold of 5 miles or less true warm time can be to little to cook the oils pollutants out. A bad PVC system will also ruin oil 80% faster. it is all about knowing your driving style, weather and car.

somthing i found in one of these groups....

One scientific measure of whether you have a sludge problem is to get a used oil analysis by a lab that has a plasma spectrometer. Blackstone Labs

is one such lab withreasonable prices and excellent service. I find that springingfor their Terry Dyson package (i.e. a plain-language interpretation ofthe results) once a year is worth it. He can see if there areprecursors to sludge in your used oil, which will help guide you indeciding how frequently to change your oil.

That's interesting. Was the car used for short runs mostly? Does it snow in winter where the car is garaged?

Jason

immediately.

Yes -- short runs, but hot climate in mid GA. Don't have the problem with out Pilot, though.

How short were the runs? I live 2.5 miles from work; maybe I should drive the '96 camry to work instead of the '99...?

Wife (a teacher) drove it to school -- about 3 miles. On the other hand I drive 27 miles each way mostly on I 75.

>

Just wondering, did you change the oil yourself using 5W-30 oil? Or did you take it to a quick lube place?

Oil change intervals are stated also by months, at 5 miles a day or maybe 50 a week it would be years before you get " Enough" miles but there is what is known as "Severe" usage and 2.5 mile trips are severe in winter, 6 months is a time frame that should be noted and is in the manual or look at Sludge and a early ruined motor. Your oils visual condition is also a great indicator. People with long life motors you will find get them hot continualy with highway driving, City short trip, you dont see long life high mile motors. So if you only drive 5 miles a day at 1000 miles your oil is crap and sludging.

If you use full synthetic oil like Mobil 1 (and not that phony synthetic sold by Castrol), and take one long trip (25 miles or more round trip) at least once every two weeks, it is very unlikely you will have a problem with sludge. This assumes an oil change interval of about 5000-7500 miles, or once per year, which ever comes first..

VW experience the same thing about that time. They recommneded certain brands/viscosities of synthetic oils. Not all met the VW requirement. They had a turbo engine.