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On The Trail Fix: A Hydrolocked Engine


A great team effort


Hydrolock, also known as "The Engine Killer," is something every off-roader dreads. Hydolock occurs when a running engine ingests water through the airbox and intake manifold into the cylinders. Since water cannot compress, the engine must immediately stop on a compression stroke, many times breaking or bending a connecting rod in the process.


The airbox on 100s and 200s are plumbed into the passenger side wheel well. While this allows fording water of up to 27.5", anything over that can get sketchy really quick. Installing a sealed snorkel on the vehicle can raise this limit to the top of the snorkel. I have never been fan of snorkels and thought them unnecessary. My stance on this has made a complete 180 after my adventure in the Ozarks.


Last week I was lucky enough to get the opportunity to explore the legendary "High Water Mark Trail" through the Ozark National Forest with some of my best friends. It was beautiful and the trails were awesome, but they were WET! After going through several water crossings and mud holes, I came across one that looked fairly deep. I wasn't sure if the bottom would be hard rock or mud so I knew I need to carry some speed through it, just in case. I lined up and hit it hard, close to wide open throttle. It turned out to be not all that deep but 2/3 of the way through the engine shut off. I tried to restart but all I got was a *WIRRRR* type sound like an electric motor that's bogged down. We looked at it for a few minutes scratching our heads. And even though the water wasn't very deep, we decided to look at the air filter. Turns out the filter was soaked. We quickly pulled the intake plumbing and saw what no one ever wants to see: about 2" of brown water standing in the bottom of the throttle body and intake manifold. My heart sank.


The straw that broke the camel's back


At this point we realized that I wasn't going to be driving out of the forest. We were probably 5 miles in and had already gone through some fairly gnarly mud holes and water crossings, so we decided it would be best to tow my truck out forward. We hooked my truck to my buddy's 100 and off we went,



Starting the long process of towing my 200 out


The going was pretty tough and after about a mile of mud and obstacles, we hit a section of trail that was basically impassible with my truck not running. Even using my winch was out because it would quickly kill the battery, The only option now was to turn around and tow her back the way we came. So out came the winches and snatchblocks to get the 4-ton beast turned around on this super tight trail.


Turning the 200 around


So after getting the rig pointed in the right direction, we made the long haul out. It actually went a lot better than I could have ever imagined. Both of my buddie's 100s ended up towing me at different times and never really broke a sweat. Even going up hills, through some mud bogs, river crossings and even a few obstacles. I was very impressed by the 100s.


Dragging the 200 through one of many mud holes


We finally made it back to the start/end of the trail. Once we set up camp not too far from the trailhead, we left to meet another buddy coming in that afternoon. By the time we got back to camp, it was dark and high time to crack open a beer, strap on our headlamps, and assess the situation.


First thing we had to do was to see if the engine would actually turn, or if it was completely locked up and destroyed. So the first order of business was to pull the spark plugs. We removed the airbox and intake plumbing, then pulled each coil pack. Next, we took out each spark plug, noting that several spark plugs were wet. 😩 During the spark plug removal, we also decided to pull the throttle body to see how much water was behind it. Our thought was that we could hopefully use towels to soak up and remove the excess water. But once we got the throttle body off and shined a light inside, we quickly realized soaking up the water wasn't going to be an option. We all stood back and looked at each other for a few long seconds before we all pretty much decided at the same time that the intake manifold was going to have to come off. In the dark. On the trail.


So we started the process of removing the intake. We removed all the vacuum lines, then took off the clips holding the fuel lines to the fuel rails. Next, we removed all of the bolts holding the intake to the heads. It all went fairly fast until we went to pull the intake and found a few clips holding wire loom to the back of the intake.


Pulling the intake manifold


After a few long minutes of struggling, we had those loose too. Once that was done, the intake lifted off easily and we pulled it out.


The 3ur-fe without intake manifold and spark plugs


Once removed. it was time to see just how much water was inside. We moved it over to the side, made sure we had someone videoing and flipped it over. Everyone gasped at the amount of water that came out. It was B-A-N-A-N-A-S!!! I bet we poured a half-gallon of water out of the intake manifold!


Dumping the water out of the intake manifold 😳


Once we cleared the intake manifold of water, it was time to bolt it back up and try to turn the engine. We cleaned up the gaskets and mating surfaces and bolted the intake back on. With the spark plugs out, the next step was to turn the engine over to clear the cylinders of water. At this point, we still weren't sure if there had been catastrophic damage that would prevent the motor from turning. I jumped in the cab and hit the starter button with my fingers crossed, AND IT TURNED OVER!!! First major hurdle cleared! There was a lot of yelling and high-fiving as the engine shot water 20 feet into the air. It was an awesome sight!!!


Clearing the water from the cylinders


Ok, at this point we've cleared the intake manifold and cylinders of water, so all that's left is to put the spark plugs back in and button her back up. After getting the plugs in and installing the coil packs, we double checked all of the vacuum lines, plugs, and fuel line fittings. Now for the moment of truth. I climbed in the driver's seat, took a deep breath and pushed the starter button. She turned and seemed to want to catch but didn't. Ok, let's try it again, Second time she caught, but immediately died. Alright, maybe third times a charm. I pushed the starter button and she hiccuped a bit but then roared to life! The engine ran rough for a few seconds but then settled down and was running smooth as silk. Unbelievable!!!


She's running!!!


Since we were miles away from a parts store, we decided to blow out the soaked engine air filter with compressed air. We ended up blowing another quart of water out of the waterlogged filter. Again, it's amazing how much water was in this engine and intake plumbing. Simply amazing.


Blowing water out of the engine air filter


Once back on the highway and up to speed, the truck threw a code. We hooked up Techstream and found that cylinders 1 and 8 were misfiring. We cleared the codes and restarted the truck and everything was fine. No more codes. I believe there was residual water somewhere that we couldn't clear out. Once the engine got up to speed, it pulled in this remaining water and caused the misfire. But after the remaining water was ingested and passed, all was good. We made it to a parts store and changed out the engine air filter with a new one and hit the trails that afternoon.


I'll always be amazed that the engine started and grateful for the all of the help from my buddies. A snorkel will definitely be my next mod. I highly recommend it if you're going to be wheeling anywhere but a bone-dry desert. I dodged a bullet this time, I'm not tempting fate again.


Back out on the trail the next afternoon


Special thanks to my best buds Andrew Nolan, Aaron Thorne, and Connor Ryan for dragging me off the trail and getting the 200 running again. What an amazing team effort!


Photos and Videos by Andrew Nolan, Aaron Thorne, Connor Ryan, and Garrett Hanska.

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