Numerous late-model piston engines from many manufacturers have suffered from failures due to oil sludge contamination. These problems happen when fine engine oil passages become clogged with sludge, and often result in catastrophic failure of the engine. 3.3 million Toyota engines were affected, as were 430,000 from Saab, 426,000 from Volkswagen, and an unknown number from Chrysler. Fixes include changing to synthetic oil, inspection, and even engine replacement.
Engines affected with oil sludge problems:
References