What happens if I ford water too high?

[Dansnare]

As I understand it, 4th Gens can ford water that is 27 inches high.

So what will happen if I try to cross water higher than that? Will I instantly do serious damage to the vehicle, or am I simply running a greater risk of damage.

I'm thinking in terms of some sort of an emergency situation where I need to cross water greater than 27 inches. Should I not even bother because I'm guaranteed to fail, or is it the kind of thing that's risky but not impossible.

Thanks.

Dan

 

[Fourty-four]

Whatever you do, be careful to avoid sucking water into the air intake.

Water does not compress, so you'll have big problems if your engine sucks some of it up.:arrow:

 

[Dansnare]

Well that's really my question.

If I try to cross water higher than 27 inches will I automatically suck water into the air intake, or is there a way to cross water higher than 27 inches and still avoid that.

In other words, what happens after 27 inches? When do I guarantee myself a problem?

For example, you say avoid sucking water into the air intake. How do I do that?

Dan

 

[hossmaster]

The risk of sucking in water through the intake is very high. Also you run the risk of getting water in the tranny and transfer case if the vent isn't high enough. Also you can suck water in the rear diff if the vent is not extended higher. Plus you will probally get water in the interior which stinks after a couple of days. The top of the passenger wheel well is where the factory intake vent is. Its tucked up on top of the fender shroud so when you hit small puddles the risk is low. Well when you submerge or get close to the top of the wheel well you will suck water in there. If you get the water into the intake and through the plenum and into the cylinders you get a situation called hydrolock. Basically water goes into the cylinder via the intake valve. Since water doesn't compress, something has to give and that is usually the connecting rod. Most cases that connecting rod will create a nice hole in the side of the engine block rendering it useless and wasted. Anything else you need to know?

 

[pipspeak]

I'm thinking in terms of some sort of an emergency situation where I need to cross water greater than 27 inches. Should I not even bother because I'm guaranteed to fail, or is it the kind of thing that's risky but not impossible.

I guess you could just detach the intake hose from the side of the wheel well and shove it up and out from under a slightly-open hood. That might get you a few more inches in an emergency.

If crossing deep water is something you plan to do regularly then get yourself a snorkel fitted, which will raise the air intake up to the roofline and out of harm's way.

 

[zig]

Lance has done an internal snorkel mod on his 4R to protect against this. http://www.yotatech.com/showthread.php?t=25167&highlight=internal+snorkel

I'd love to do this, even though I don't think that I'd ever get that far.

How about electronics?

 

[JosephD05]

How deep of a puddle can the stock 4 runner handle without any damage or the use of a snorkel?

 

[4RunnerRon]

A couple weeks ago I was driving up to see my brother in Chico, Ca and it was pouring rain that day. One of the roads leading into town was closed because the river that runs alongside it was flooding the road in some spots. Of course, being the ever confident driver of an 06 4Runner, I drove AROUND the Road Closed sign. So long story short, I found that the 4Runner can ford about 2 feet of water, or roughly to the bottom of the driver's door. The key is to KEEP MOVING through the water and don't take your foot off the gas for more than a moment. If you do, the backpressure from the exhaust will suck water up the tailpipe(s) and damage the engine. Fortunately, my path was clear and I cruised through at a few miles an hour. Aside from a dirty truck and some river sludge in the bottom of my door frames, she took it like a champ... and now I know just how much I can push it without a lift. Hope that helps!

 

[JosephD05]

A couple weeks ago I was driving up to see my brother in Chico, Ca and it was pouring rain that day. One of the roads leading into town was closed because the river that runs alongside it was flooding the road in some spots. Of course, being the ever confident driver of an 06 4Runner, I drove AROUND the Road Closed sign. So long story short, I found that the 4Runner can ford about 2 feet of water, or roughly to the bottom of the driver's door. The key is to KEEP MOVING through the water and don't take your foot off the gas for more than a moment. If you do, the backpressure from the exhaust will suck water up the tailpipe(s) and damage the engine. Fortunately, my path was clear and I cruised through at a few miles an hour. Aside from a dirty truck and some river sludge in the bottom of my door frames, she took it like a champ... and now I know just how much I can push it without a lift. Hope that helps!

yeah I know about the back pressure. I would put her in 1. Thanks.

 

[Thai]

If you were planning on doing repetitive water crossings, then the FIRST mod is the rear differential breather tube! This is the lowest point where water/mud can damage your 4runner. And this is BELOW 27". Keep that in mind.

In addition, i have not gotten any definitive answer on whether the transfer case or automatic tranny has a breather tube. I know that there are two breather tubes in the engine bay...but i am not sure where these two tubes come from. Anyone? I assume that one of the tube is for the front differential.

Typically, you need to have 4 breather tubes: front diff, rear diff, automatic tranny, and transfer case.

Therefore, i would not try over 2 feet of water on any SUV without modification.

 

[Expat]

You are asking about an emergency situation right?

If so...here's my thoughts/procedures

If you are fording a water crossing that would require a brief immersion at mid door level for approx 20 seconds......first walk the crossing to establish depth along the path of the wheels. This is important as if you drop a wheel into a deeper hole your in trouble. Have a spotter stand on the otherside to keep track of your line, then follow the procedure...

1. Allow the differentials to cool

2. Place a plastic sheet across the front of the vehicle from the bonnet down to the factory skid (this will slow ingress of water to engine bay and assist you creating a bow wave)

3. Disconnect the fan belt (not sure about the implications of this on the 4th Gen - I'd have to look first)

4. Ensure all windows and doors are closed. If you have doubts about the seal along the door, line the seals with a coat of vaseline (petroleum jelly)

5. Select 4low and lock diff

6. Enter water slowly but with enough momentum to create a bow wave - this is probably your most important technique to a successful water crossing.

7. Keep your line as per your walk-thru

8. Avoid backing off the gas but do not be tempted to speedup once you have a bow wave - speeding up may throw the water over your bonnet - now your a submarine!

9. Focus on your exit point and preferrably stop on a slight rise or fall on dry land so water will run off rather than pool. Remember your brakes will be wet.

10. Once parked (should be quickly after exiting) do a thorough inspection of engine bay in particular. Depending upon your emergency you may want to take time to disconnect your air intake and check for water. Hopefully the radiating heat from the engine bay and block will evaporate any minor pools of water around electrics/intake etc.

Naturally every situation will be different and it will be a personal call as to what risk you want to take depending upon your emergency. If someone requires medical treatment urgently you will proceed differently from a situation where everyone else in your trail group have well prepared trcuks for water crossings and have already crossed and you are not as prepared as they are but you REALLY want to!

27 inches would put the depth about 1/3 door height correct? At this height I think there would be a few more inches before the intake would be a problem. Definitely the rear diff breather would be a problem as its only mounted on the top of the diff which is less than 27inches so hence the need to cool the diff first. I also think the extended brether for the front diff is heigher than 27" on a stock 4th gen but I'd have to check that too. I thought the transfer cases were all sealed so no breather? I've got a full set of manuals at home so I'll look this up later.

I guess there might be differences between v6 and v8 model too - related to transfer case variations????

Bottom line is this - get water in the intake and your screwed. Be very aware of the height of the intake for your truck - depending upon any mods eg body lift, suspension lift, bigger (higher) profile tires, cargo weight and it effect on loading down the suspension.

Cheers
Mark

 

[Thai]

I thought the transfer cases were all sealed so no breather? I've got a full set of manuals at home so I'll look this up later.

I think that all transfer case and auto tranny have a vent...to cope with heat buildup.

 

[jrc_bar]

I went to a small tips course at my Land Rover Dealer when I bought my last Land Rover.
The tip the instructor gave us for fording was not to speed when doing so. And While doing it you need to be aware your car is making a arrow shape on the water. And finally not to increase speed but keep it constant as they say the top cause for your car to stop while fordin is water soaking the intake. By doing the arrow on the water you are pushing water to the sides instead of letting it fill your entire engine bay.