7.3L OIL COOLER OVERHAUL

ADDRESSING ONE OF THE VENERABLE V-8’S MOST COMMON LEAK POINTS

- MIKE MCGLOTHLIN

Not unlike other aging diesels, as the 7.3L Power Stroke grows older it begins to develop oil leaks. As the years roll over, you’re bound to encounter a small leak from the dipstick adapter, a drip-drip from the oil cooler, or the dreaded seepage from a rusted out oil pan. Luckily for the owner of the ’97 F-350 in this article, a small oil puddle was discovered on the driver side of the engine, where it was quickly traced back to the oil cooler. Upon closer inspection, the outer O-rings had failed, meaning a re-seal was all that was in order, not complete replacement ($68 vs. roughly $300).

Regardless of cost, the oil cooler has to be removed to solve the problem. Fortunately, it’s a relatively simple job that a novice can tackle at home. With a few simple hand tools, a couple drain pans, and the right replacement parts from Riffraff Diesel Performance, we were able to handle the job in three hours’ time. While a leaking oil cooler is more of a nuisance than a major issue, a few drops of oil will eventually turn into a puddle under your ’94.5-’03 Ford. For that reason alone, it’s best to address this pesky problem before it gets worse. Follow along to see how we did it.

After more than 217,000 miles and nearly 24 years of loyal service, we’d say the factory oil cooler had a pretty good run aboard this 1997 model year 7.3L Power Stroke. Finding a wet spot where the oil cooler housing slides into the rear header (also known as the oil cooler filter adapter or oil filter base) or front header is a telltale sign that the outer O-ring has failed. Early on in the failure, engine oil leaks past the O-rings when it’s cold, but stops leaking once warm (when the O-ring swells). Although you can get by with a leaking oil cooler for quite a while, the problem will only get worse until it’s addressed.