The following is an article I wrote for offroad.com, based on my experience with water in the '92 Trooper I traded for my VX.
Hydrolocked: a Lesson in Deep-Water Fording
Though sand typically drains quite well, the soil under the sand at Beverly Dunes Off Road Vehicle Park in central Washington is apparently less than permeable. The area is typically arid, however the week before our “dunes playday” it had rained heavily, causing water to pool up in some of the depressions among the dunes.
I drove through the edge of a large pool in my ’92 Trooper once; no problem. I drove through again, this time a little further from the edge. The water was about to the bottom of my door, though it seemed deeper from inside. Still, no problem. I thought this is cool, and it must look even cooler! I asked a buddy to station himself at the opposite end of the pool and I would drive toward him so he could click off a photo or two.
He was in position and ready. I proceeded. My earlier trips through had spawned some current action, causing a log to drift slowly across my path. I steered left to avoid it, which placed me just about in the center of the pool -- in uncharted territory. The Trooper’s nose dropped about a foot into a hole and all of a sudden the water was a whole lot closer. Instinctively and mistakenly, I hit the throttle. The sandy bottom offered excellent traction, and for the first time in my experience, the Trooper labored in 4-Lo against the resistance of the water. This created a “bow wave” that began lapping at the base of the windshield.
The engine died, but the Trooper had enough momentum to get the front wheels on dry land before rolling to a stop. I was congratulated by my buddies for making it ashore, and was assured by the photographer that the stunt had been captured on film. Relief and jubilation changed to horror as I attempted to crank the engine. A terrible sound emanated from under the hood like a starter engaged on an already running engine. I popped off the top of the air-filter box. The K & N was dripping wet.
We started pulling spark plugs, finding one cylinder completely filled, and a second partially filled. The engine was cranked, allowing the pistons to eject the water through the plug holes like a bulimic supermodel. Along with the water came impressive quantities of black carbon. When nothing but gasoline came out, we put her back together and she fired right up. In fact, during the 145-mile trip home, the Trooper seemed to have more power and had never run better!
Not long after, my speedometer would stop working intermittently – until my next attempt at deep-water fording that disabled the speed-sensor for good. This little jewel is located next to the transfer case and was eventually replaced, correcting the speedo problem. 60,000 miles later, I’ve had no other fording or hydrolock-related problems
Lessons Learned:
· Hydrolocking with an automatic transmission is not a serious matter because there is not a direct/mechanical link from the engine to the ground. With a manual gearbox, unless you can engage the clutch before the compression stroke of the hydrolocked cylinder, you will hear the sound of very expensive parts breaking because water is not compressible. The most likely noise you will hear is the sound of a connecting rod, freshly bent to 90 degrees, exploding through the side of the block.
· Without a snorkel, the absolute deepest fording depth is the height of the air intake, or roughly the top of the front wheel-well opening, about 34 inches in a stock Trooper. My door seals and transfer case lever boot held, but maybe I was just lucky.
· Carbon deposits in the combustion chambers are not fuel-soluble, and don’t necessarily get “blown out” after a long trip, but they are effectively removed by water. I’ve been told by veteran mechanics that pouring a quart of water down the carburetor at a high idle is an old remedy for carbon-choked engines.
· If you submerge driving lights, headlights, or taillights, it will be necessary to disassemble and dry them out within a couple of weeks. Water left in will not evaporate out and will cause rusting of reflective surfaces and eventually, rusting of the filament-support framework.
· Before attempting deep-water fording make sure diff and transfer case vent tubes are as long and high as possible, extending them if necessary. After fording, if the gear oil is milky or muddy-looking, drain and re-lube.
· In most off-road vehicles, the radiator fan is clutch-controlled so it will not turn when submerged. Note how it can be spun by hand when the engine is off.
· The Off-Roaders’ axiom “as slow as possible, as fast as necessary” is nowhere so true as when fording deep water. If you go too fast, the bow-wave phenomenon will get you!
Spraying your engine with fresh water will NOT be a problem.
Rick "Baxman" LaMarche
Supercharged, Dynamated. SCCA Oregon Region rallycross class winner
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