You might have seen the video above on Reddit that shows a nasty oil change where the lubricant is the color of milk chocolate and flows out of the vehicle in a gross sludge. Motor1.com reached out to the technician Chris Mertz who took the video, and he offered some more info and photos of what happened.

The vehicle in the video is a 1999 Chevrolet Tahoe two-door. The owner said the SUV had been overheating for a month – a pretty serious problem to ignore. The Chevy eventually stalled, and the owner finally brought it into the shop.

Gallery: Engine Oil Sludge

Mertz is part of the family that runs Mastertech Auto Care in Plano, Texas. After finding the disgusting oil sludge, the mechanics started trying to find the cause for the issue. It turned out the intake gaskets failed, causing the overheating problem. The engine running too hot for so long eventually cracked the engine block.

While the owner should have been more concerned about the chronic overheating, Mertz was clear that this sludge was not related to a lack of oil changes. The Tahoe was about 2,000 miles from needing fresh lubricant.

"By far the worst oil that I have ever seen come out of a car," Mertz told Motor1.com. "I have been working in automotive for about 8yrs now, between being a mechanic, service writer, and general manager."

The owner must have a soft spot for this Tahoe because rather than scrapping the SUV with the sludge-filled engine, the person elected to get a remanufactured long block replacement. According to Mertz, the damage was too extensive simply to rebuild the powerplant.

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