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