The Fuel Cooler Issue is probably the #1 method of engine failure we encounter with the D4/D6 engine. The fuel cooler develops a small "weep", causing the hose carrying salt water to swell up and "pop" off. This sprays salt water everywhere in the engine room, especially into the air intake of the engine next to it. By the time the operator gets the overheat alarm for that engine, the damage has been done and you'll find your self needing one, two, maybe even three (we've seen this before) new engines, rebuilds, or long blocks.
Ways to Prevent it:
PROPER PREVENTATIVE MAINTENANCE!!! Checking the oil on your engine? Take two seconds and wipe the hose connections at each end of the fuel cooler with your finger and smell your finger. If it smells like diesel, It's time to replace the cooler. Consider replacing with a Swedish Lorry Parts IC-230 that carries a better warranty and price tag.
We strongly recommend replacing both sea water hoses while you're at it, and anytime you replace a hose you should use new hose clamps. We carry the bonded seals for the fuel connections as well. Matter of fact, we sell a kit with the whole shebang complete with a 3 year manufacturer's warranty. D4/D6 Fuel Cooler Replacement Kit.
You can replace this fuel cooler and its components for less than a thousand dollars before it fails OR spend tens, maybe hundreds, of thousands of dollars rebuilding or long-blocking your engine(s) when it does fail. The choice is yours.
We have been asked if our recommendation differs whether the vessel is in fresh or salt water. Since the failure is always on the fuel side, leading to failure on the raw water side, our recommendations regarding preventative maintenance does not differ if the engine operates in freshwater.
