Found out that 90% of diesel engine failures are from water in the fuel, not mechanical wear

I was reading through some Cummins service bulletins last night (boredom, I know) and stumbled on this stat that blew my mind. They analyzed warranty claims over 5 years and water contamination caused 9 out of 10 failures. All that time I spent worrying about piston rings and injectors, and it's basically just wet fuel killing these things. Anyone else find this hard to believe or have you seen it firsthand on jobs?

2 comments

2 Comments

camerona791mo ago

Calling BS on that number being accurate across the board. Water in fuel is definitely a problem, but 90 percent? That sounds like a stat they cooked up to sell more fuel filters and water separators. I've seen plenty of diesels die from injector pump failure, cracked heads, and just plain old high mileage, not just water. Unless you're talking about guys who are too cheap to buy a decent filter or live in a swamp I bet the real number is way lower. Still good to drain your water separator regularly but don't lose sleep over it.

reed.eva1mo ago

Had a buddy lose a brand new Duramax to a bad fuel station tank, sucked in pure water.