Waterlogging story

[Saturn]

So I had recently seen a couple threads from folks having water entry issues, one with a blown motor and a few with close calls. Here's my story. Skip to the second paragraph for just the mechanical stuff, but who doesn't love a good story

 

I foolishly ignored the warnings to relocate the R50's low-hanging intake and took my Pathy out into an area with a big puddle in it, I had a that I like girl with me(mistake #1). I crossed the puddle (more like a miniature lake) fine all the time so I figured I'd show off my truck a bit, especially now that I had added a 3" lift, what could go wrong? Well I crossed it fine to a dry spot in the middle I always turned around on, it just got really swampy and dead-ended after that. On the way back through I figured I'd hit it hard and rev it up, throw some mud to impress the my passenger, but the extra revs and entry speed ended up vacuuming up water, more than I expected. Now, I've had water in the motor before, and it always just bogged a bit and then ran fine, but this time the lights started going out and the revs dropped super quick as I neared the edge of the puddle so I killed it and it just coasted out. Because of my previous experiences where I was able to just force the water out through exhaust ( a trusted mechanic had me do this, and it had worked twice on wheeling trips in Ocala), I ignored every single other piece of advice on this matter and tried to start it. It started, ran for like 3 seconds, the died. It didn't sound like it was knocking, so I hopped out and pulled my plugs (thank God I carry a ton of tools), and turned it over, a small amount of water came out, but not a whole lot, I'd seen videos of guys doing this before and it was always way more explosive so I thought something else must be off, it still wouldn't stay running. I I tried drying stuff off, only running the cleaner-looking spark plugs, just wouldn't work. Luckily the girl had an F-150 that she drove to meet me, so she dragged my truck to the parking lot as it was starting to rain and get dark out. After trying to start it with the gas pedal down to cut off the fuel pump so it flush all liquids out, it still wouldn't go, so we began dropping the driveshaft so she could flat tow me up to my shop about 7 miles away. It was pouring rain and pitch black by this time, but waterproof worklights and tons of tools got the driveshaft down and tied out of the way. It was an incredibly sketchy trip with no brake booster in the darkness but she got me to the shop and drove me home. Bad news was I had to work the next day and was leaving for Moab right after I clocked out. So I drove my mom's car (thank God she was out of town) to work and told the guys the had a good mechanical ticket on my truck, make it run before I get back in a week. I trust the guys there with my life every day, so I trusted them with my beloved Pathfinder, after going over it with the mechanic, i wondered if it was maybe an electrical issue, and considered the MAF as I knew R50s had common issues with those, but I was still a nervous wreck at the possibility of my Pathy needing a new heart. I went to Moab and relaxed, went jeeping with some family, and finally got a call from the head mechanic, who's kinda my mentor, on the 4th day of the trip. "CAN YOU HEAR THAT?" He tried to shout over the air compressor. "NOT REALLY" I said. "WELL YOU'RE TRUCK IS RUNNING. NOW GET BACK HERE, THE OTHER TIRE TECH SUCKS!". So I picked my R50 up the night i got back and drove it home.

 

So now for what happened mechanically, and how I adjusted my truck and my kit. First, water got in and drowned the MAF sensor, I honestly didn't think about this until I got it to the shop, and I kicked myself for that. The motor couldn't tell how much air was coming in. The mechanic who was working on it said that he unplugged the MAF and it ran, but very rough and it wouldn't rev high. So he replaced that, ran Seafoam through it, threw a new set of plugs in it, and she was purring like a kitten again. So here's the thing: water and mud got into the motor, I looked into cylinder #2 with a borescope before I left and there was definitely mud in it. This is the third time water has entered the cylinders of this engine. EVERY mechanic and 4wheeler on forums youtube says that water doesnt compress and WILL destroy your engine no matter what because fluids don't compress, but then again gasoline is a fluid too and the engine handles it just fine on compression. I'm not saying water doesn't do anything to the engine, but how in hell has my VQ not blown? It runs perfect now, no damage was done to the motor itself, happily revs to redline whenever I please after water intrusion 3 times. I did learn my lesson though, I did sort of a Fleurys style intake relocation ( http://www.nissanpathfinders.net/forum/topic/25150-my-new-selectable-air-intake-with-a-little-extra/?hl=%2Bsnorkel+%2Bwater+%2Bsensor ) with some 3-inch universal intake hose by Specte, the stuff is great, I might do a full thread on that later but but it's pretty similar to his. If you haven't done it yet it is DEFINITELY worth it, it was like 20$ for everything I needed, no reason not too. I just lazy and overconfident before. I also went to a junkyard and grabbed a spare MAF sensor from a derelict QX4 as well as bought a new set of spark plugs and a can of seafoam, so even if this happens again I can get my Pathy running. So yeah my .02$, actually quite a bit more given the length of this post. I also want y'alls opinions on what to do if you think you have water in the motor, keep it running or shut it off? I'm always inclined to shut if off so I can flush it out, as long as I'm not in super deep water, which I avoid as I always check depth before entering. I knew the depth of this puddle, I just hit it too hard. but yeah, cheers!

 

 

 

 

[Citron]

My understanding is that there needs to be enough water to prevent the piston from reaching tdc. If there is enough, the piston can't compress it and it can't continue up. Then you are hydrolocked. If you are doing high enough rpms when this happens, you can damage things, blow out rings, break connecting rods, wrist pins, etc.

 

In your case, you probably never had enough water in it to fill up the cylinder. However, the dirt has to be scoring the cylinder. Shutting it off is a good idea. Oil change asap too.

[Saturn]

My understanding is that there needs to be enough water to prevent the piston from reaching tdc. If there is enough, the piston can't compress it and it can't continue up. Then you are hydrolocked. If you are doing high enough rpms when this happens, you can damage things, blow out rings, break connecting rods, wrist pins, etc.

 

In your case, you probably never had enough water in it to fill up the cylinder. However, the dirt has to be scoring the cylinder. Shutting it off is a good idea. Oil change asap too.

 

I dunno, I certainly have been exceedingly lucky. I guess I thought that when the piston was at TDC the fuel/air would be so compressed that any additional substance would be too much, but maybe not. The dirt was sucked out before the truck ran and the oil was changed before it was driven. This happened over a month ago, I just never got around to posting it cause I like to post full stories and I've been super busy.

[Slartibartfast]

Makes sense that a wet MAF would cause problems. I'll have to remember that one in case I get ambitious with a big puddle at some point.

 

And yeah, a gas engine can take a bit of water without blowing up. Some guys use a water spray like seafoam, or run water/methanol injection to reduce temps while also raising compression. Since the water's not compressible, the air/fuel mix has to compress more, which can good to a point. Go too far and, like Citron said, you end up with a piston ramming into something it can't compress, and that's when the Kool Aid man visits your crankcase.

 

I've always heard that you shut it off and blow it out (plugs out) rather than risk ramming it into a slug of water with the starter motor, or starting it and having it immediately ingest more water that's pooled in the intake.

 

How did mud get in there? Did your air filter come loose or something?

[onespiritbrain]

I am glad your engine survived!

 

I'm uh, giving up the 5th amendment here, but yeah.. while I was 3 foot deep in muddy water my engine would not run because of my wet MAF. I had to spit on it to get the clumps of mud off and then blow on it till it was dry... only then I was able to adequately destroy the engine by running it with a gallon of muddy water inside.

 

In my case the air filter blew a giant hole in the center after it got wet and clogged.

 

I had major amounts of water in the crank case and that water boiled when I ran the engine which blew every single seal imaginable.. poor engine looked just pitiful leaking that much oil from everywhere.. horrible.. still hurts my heart what I did to my beloved pathfinder.. she's back to life now though!

 

We have got to get snorkels... I want to figure out if there is a way to pull air from the fresh air cowl and if it will still be protected if water rushes over top of the hood right into the cowl. I mean I'm pretty sure that water wouldn't have started blowing out of my AC vents.. maybe there is more air flow involved though. I might start a thread about this when I get ready to move forward with it..

 

 

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Edited August 4, 2017 by onespiritbrain

[Slartibartfast]

BleepinJeep did something similar to a Heap recently. I don't know if the Pathfinder intake routing would be as cooperative but I guess you could run up the inner fender and punch into the cowl from the end. So long as the intake wasn't right at the bottom of the cowl or right under one of the vents (so the cowl could still drain a fair amount of water without the intake sucking it in) it looks like a good way to go.

 

I hadn't thought about water boiling in the crankcase! That's awful. I'll bet it didn't do the bearings any favors, either.

[Saturn]

Makes sense that a wet MAF would cause problems. I'll have to remember that one in case I get ambitious with a big puddle at some point.

 

And yeah, a gas engine can take a bit of water without blowing up. Some guys use a water spray like seafoam, or run water/methanol injection to reduce temps while also raising compression. Since the water's not compressible, the air/fuel mix has to compress more, which can good to a point. Go too far and, like Citron said, you end up with a piston ramming into something it can't compress, and that's when the Kool Aid man visits your crankcase.

 

I've always heard that you shut it off and blow it out (plugs out) rather than risk ramming it into a slug of water with the starter motor, or starting it and having it immediately ingest more water that's pooled in the intake.

 

How did mud get in there? Did your air filter come loose or something?

 

Air filter didn't come loose but it was totally clogged, had a few rips in it , probably from the vacuum once it was soaked. Not a whole lot of mud got in, just a little in cyl#2, like I said it's been a while and the motor runs great now so I think the oil protected the cylinder walls from the dirt. MAF cleaner is kinda expensive for a spray, but I carry some of that too now.

[onespiritbrain]

 

Air filter didn't come loose but it was totally clogged, had a few rips in it , probably from the vacuum once it was soaked. Not a whole lot of mud got in, just a little in cyl#2, like I said it's been a while and the motor runs great now so I think the oil protected the cylinder walls from the dirt. MAF cleaner is kinda expensive for a spray, but I carry some of that too now.

Yeah man, that's awesome that your engine made it! Near death experience for sure!

 

CRC Electronics Cleaner

https://www.amazon.com/CRC-5103-Quick-Electronic-Cleaner/dp/B000BXOGNI

 

I've seen it at Walmart for $5 a can also. It's the same stuff as MAF Sensor Cleaner. The MAF stuff might be more gentle on buna rubber..? The CRC Electronics Cleaner mentioned above will elongate buna rubber seals. Nowhere near as bad as brake cleaner products but it still does a little bit.

 

 

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