OEM QUALITY, HIGH RPM INSURANCE

BY MIKE MCGLOTHLIN

With a 19-year track record under its belt, it’s safe to say the Duramax is one of the more reliable diesels to ever grace the ¾-ton and larger truck segment. Sure the LB7 had injector problems and the LLY’s ran hot, but by and large the 6.6L V8 holds up remarkably well—regardless which generation engine it is. We’ve even seen well-maintained Duramax mills accumulate more than 700,000 miles without needing an overhaul or any other major repair. But while the Duramax is no stranger to racking up hundreds of thousands of miles, it’s not immune from requiring a minor repair from time-to-time.

Following the purchase of a high-mile ’06 Chevy Silverado 2500 HD, the truck’s new owner noticed the LBZ was low on coolant. The cause? The 13-year-old, 251,000-mile factory water pump was on its way out. After getting a quarter-million miles out of the original water pump, it was an easy decision to stick with an OEM unit. And thanks to Merchant Automotive’s water pump kit, not only was the owner able to start over with a genuine AC Delco unit, but the new pump was modified to hold up to elevated rpm and higher horsepower. If you plan to keep the water pump alive in your modified Duramax, look no further than Merchant Automotive’s TIG-welded unit.