Engine Sludge has ruined thousands of automobile engines, often surprising car owners who thought they had done proper maintenance.
Automakers responded poorly, leaving thousands of customers in the lurch.
Sludge prone engines in some cars from Chrysler, Dodge, Toyota, Saab, Volkswagen, Audi, and Lexus from 1998-2004 await unwary buyers.
But any engine can develop sludge if maintenance is delayed.
Class action lawsuits have resulted in settlements, but no manufacturer has issued a recall.
News reports still trickle in, offering a continuing picture of used car buyers whose bargain dream car turned into a sludge monster. Sludge is gelled oil, with its additive package depleted by heat and contaminant accumulation. Oil galleries, small passages in the engine block and cylinder head, can build up deposits. These block delivery and starve engine components of life giving oil.
Once the oil galleries are blocked, reverting to manufacturer's recommended oil change intervals generally fails to reverse the sludging.
Engine failure due to oil gelling is expensive, and in sludge-prone engines, can be repetitive.
Among cars that sludged, mean engine failure occurred at 63k miles.
A few poorly maintained engines locked up with as little as 15k.
Many still had warranty coverage, but numerous claims were denied.
Rental fleet cast-offs and lease returns, which often are poorly maintained by first owners, composed the majority of sludged engines.
Oiling problems are not a new issue.
In the early days of the auto business, motors were routinely disassembled and scrubbed with kerosene.
My father was the third owner of a 1956 Plymouth V-8 that sludged up in 1961, despite his regular maintenance. I went to the dealership and watched it being steam cleaned. Oil change intervals had been getting longer for a couple decades without incident when the sludge problem reappeared. An engineering crisis in the mid-1990's brought the sludge monster back.
Evolving emissions standards and fuel mileage targets added new complexity to drive train engineering, putting pressure on overworked design teams.
Here is a very brief overview of a few of these issues.
Aluminum engines with new heat transfer rates combined with hotter internal temperatures for emissions compliance, often overheating oil.
Finer internal tolerances and friction reduction called for lower viscosity motor oils.
These thinner lubricants allowed smaller pores on oil pan uptake screens which tended to clog easily. Front wheel drive compacted entire drive trains in crowded engine bays, where heat from tack-on turbochargers and catalytic converters built up. Cylinder heads evolved with three and four valves per cylinder, variable valve timing, and overhead cams with their associated chains and gears.
This new head complexity and crowding gave engineers few alternatives but to downsize valve guides, oil passages, spark plug threads, and coolant galleys.
Long life antifreeze and radiator maintenance intervals up to 100,000 miles allowed some cooling systems to deteriorate.
Coolant leaks contaminate oil quickly.
So beginning in 1996, problems with extended oil change intervals developed.
Late model cars began to show up at dealer service bays with sludge in engines.
Dealers kept this quiet, often claiming they had never heard of the sludge problem.
When manufacturers saw the mountain of warranty claims coming, denial took over.
Many builders denied warranty claims, claiming improper maintenance as the cause of sludged engines.
A certain percentage of new cars will inevitably be improperly maintained, but engine sludge occurred more frequently in selected models.
As the problem grew, internet owner's forums filled with posts about weak customer service, claim denials, and dealer stonewalling. Eventually extended drive train warranties were offered by VW, Toyota, Audi, and Saab. Troubled Chrysler declined to offer extend warranty protection or speed up claims.
For engines engineered liable to sludge, flushes are offered, but no good solution is available.
But to prevent oil sludge better maintenance is suggested.
Avoid the illusory savings of quicky lube shops.
Manufacturers "severe service" or "severe climate" oil drain interval listed in the owner's manual should be followed.
This means every oil change receipt should show mileage lower than the figure specified.
Some owners report being disqualified for just a few miles over.
Replace the PCV (crankcase ventilation) valve every 30K miles.
Every single service or repair receipt must be retained, showing the vehicle identification number (VIN), date, mileage, and description of service performed.
Never drive with an overheated motor, repair the cooling system and replace the oil immediately. Cooling systems should be serviced more often than manufacturer's specs. Short trips in cool climates don't warm up motor lubricant fully, allowing condensation to build up. Just taking the car for a longer ride every two weeks might help.
Car buyers beware "hot deals" and "low payments."
Many oil sludgers were "bargains."
As new cars, many were moved with heavy incentives, low-front-money lease contracts, and rental fleet package contracts.
Previous owner's service records should be central to the used-car evaluation.
Source by Ed Sherbenou