???? Odd problem

[Rbeado]

Anyone ever had this one. M998 with a 6.5 4L80 conversion. When it rains water fills the engine crank case with water. Going to look at it this weekend but figured I would put it out there. It is quite a weird one.

[Augi]

Does it have a hood on it?

[Action]

Do you mean that the engine fills with water mixed with the oil? Or do you just mean that the top of the engine (valley) gets a big puddle of water in it?

Jason

[actionpaintball]

Short from there being an obvious path into the block, I could only think of an intake problem. If you have access to an evap/smoke machine, that might be the fastest way to diagnos....just smoke the intake, and then the exhaust.

[Rbeado]

It does have a hood on it. My thoughts towards the intake would be that with the amount of water in the crank case, the engine would hydrolock upon startup. I will look into it this week end and post any findings. Coolant level is not dropping. Oil level only rises after washing engine bay or a good rain.

[Hell On Wheels]

Well if you eliminate the possible head gasket, cross over tube or all hose clamps on the intake housing during your troubleshooting, here is an old place to look. On the passenger side, on the air cleaner housing, on the bottom side, if you remove the mud/dust plate that protects this housing from the tire throwing stuff into, behind it there is a small rubber hose about 1 inch long by 2 inch wide that seals up when the engine is running but only opens when it fills with trash or dust. It could have fallen off and your intake will suck in water and trash. Remember it is on the outside of the air cleaner housing on the bottom behind the dust cover behind the wheel.

[Action]

Is the Humvee just sitting there or are you driving it? I assume it is just sitting there, because you dont want to start it. If so, then the water is likely not coming in from the air filter bacause it would have to rise higher than the motor to get in. Alos, the duckbill does not open by itself or seal when the engine is running. It is always closed, even if sitting on the floor. You have to manually squeeze it to let water and dirt fall out. If your Humvee has had a fording kit on it, that duckbill should have been replaced with a solid rubber cap. If you have the rubber cap under the filter and you do not have the mushroom intake cap on, that could all fill with water.
If not from there, then install the rubber seals and trim on the back edge of the hood. See all those small holes across the hood below the windshields? That is where the seal retainers rivet in.
You will still need to find the entry point.

Jason

[gunchief113]

Ok, not the air filter, as the filter would collapse, or at least bog down engine running. If the intake were at issue, the engine would bog down, crack the head, etc. Further, water would be blown out the exhaust. This is a conversion, so I am guessing that the rings are tight in the new engine. You need to look for a direct route for water to get into the case. This leaves the following:
Oil cap (obvious, so unlikely)
Oil filler tube to timing cover seal (right at front, and hard to see if you aren't looking)
Tachometer and its mounting seal (rear of valley, so water would sluice right to it)
Dipstick tube to pan joint (not likely)
Timing cover to block gasket (particularly under inj pump in the valley)
Inj pump to timing cover gasket (possible, but not likely)
Oil pan to timing cover and engine block gaskets (dodgy joints, particularly at bottom of timing cover, but would likely show oil leakage))
Timing cover front seal at harmonic balancer (would likely show oil leakage though)
Just my $.02.
Good luck!

-Brian

[Action]

What does the oil look like on the dipstick?

[Rbeado]

Narowed down to something at the vally. There is about 1" of water in the valley after a nice rain that we had and the crank case had 4Gallons of water in it!!! Fresh water not antifreeze. Update to follow

[fsutterbadass]

Believe it or not this happened to me one time. I put a civilian hood on a military truck and it did not have the weatherstrip at the rear edge of the hood....and when it rained, the water just poured into the engine bay.....not to say that's how it made it's way into the engine.....that was only part of the problem....the real culprit.....the short, asymmetrical hose from the CDR valve to the crankcase was incorrect.....someone had use a hose they cut, not realizing that each end of the hose had a different diameter.....and rainwater trailed down the hose, past the ill-fitting clamp and into the crankcase. like 2-3 gallons of water! i drained the crankcase and turned all the water out of the engine.....replaced the bad hose with the correct hose and clamps and it never happened again. Not saying this is what's happening to you.....but this is what happened to me. Check it out.

Thanks,
Freddie

[86humv]

The 6.5 has a drain hole at the back side of the valley...it drains water thru a tube which comes out next to the two oil in / out hoses, if its clogged , valley will fill up and maybe go into Tachometer area if gasket is bad.

[dunsbr]

An AMG Engineer told me that the rubber strip on the back of a humvee hood is only there to stop 5.56mm and 7.62mm cartridge cases from falling down into the engine bay and bouncing around and damaging the fan.
s purpose is not as a water or air seal.


Cheers

[D Pizzoferrato]

A couple of other possible entry points are a faulty or missing gasket between the IP and timing cover or a bad gasket between the timing cover and block (or a cracked timing cover in the area of the IP).

These engines (both 6.2 and 6.5) will run fine without the intake manifold in place, so any faults in the intake to head gaskets will not likely show it's presence thru driveability issues. Faulty intake manifold gaskets would give ample opportunity for water in the valley to enter the crankcase.

The valley side of the heads is not within the combustion chamber; this is where the push rods pass thru, so a crack or fault in the head gsket in this area will also not show any driveability issues but would be a good place for water to drain into the engine from the valley.

[fsutterbadass]

i just know in the absence of that rubber strip, my valley filled up with so much water, it was laughable. not saying it's sole purpose is to prevent rain from entering, but it must help deflect it to some degree. since i installed one, my valley doesn't show near the level of moisture. \\\