Valley Drain

[johncarrol]

I ran into a problem with the valley drain hole in the back of the engine and have some questions. First this is about the 6.5NA that is in my HMMWV. I tried to post this on the 6.2/6/5 tech, but for some reason I was not able to. No problem for me if it gets moved. I thought the hole was plugged at first, which caused water to lay around and corrode my IP and caused it to leak. Trying to clear the hole, I realized it was blocked off for some reason and there was a small core plug installed where the tube would have exited on the drivers side of the back of the block. I used a small punch to force the core plug into the bell housing area and tried to clear the hole going through the back of the valley. the punch went up against something solid and would not break through. Has this ever happened to anyone else? I do not want to pull the transmission to fix this. does anyone see any problem with me trying to drill through the hole to let any future water or anything else drain out in the bell housing area.

[sctrailrider]

I haven't seen one plugged like that, sounds like a previous owner did it...

Other than drilling into the flywheel I don't see anything wrong with drilling a hole , auto trannys don't normally have the tube, manuals do to keep stuff off the clutch disc..

[johncarrol]

It was a fresh rebuilt engine that was installed in my HMMWV from a rebuilder contracted by the military. I was lucky to purchase just the parts to repair my leaking IP (plunger and seal). I was told it was a common problem in HMMWVs that sit outside for an extended period of time with water not draining and corroding the bottom of the pump to the point that the housing was too damaged to reuse for a rebuild. In my case, instead of the hole being plugged with dirt or rust, it was blocked off. I was lucky to save my pump before it was too late.

[johncarrol]

I'm posting this reply to maybe save someone else from making one stupid and one VERY stupid mistake that I made. I decided not to drill the hole out to drain the valley of water or anything else. Because my HMMWV doesn't sit for any length of time, any water will evaporate before it causes any problem and with the removable rear engine cover, I can easily check it. I decided to also repair a slight valve cover oil leak at the same time repairing the IP. HMMWVs are not the easiest vehicles to do engine work on because the body is more built down over the engine than other vehicles. The job took me more time than I thought, because I wanted to take my time and only need to do it once. What a joke! This has been the best 6.5NA I've ever owned. It only has 10,000 miles on the rebuild and runs like a new engine, but I almost destroyed it. When I was bolting the timing gear back on through the filler tube hole, I looked through the hole. Everything looked great. I ran the first bolt with threadlocker in and tightened it. It felt like it bottomed out solid, so I finished tightening it. I indexed to the other holes and did likewise. When I started the engine, everything seemed ok except I heard a slight rubbing noise from the IP area. I drove the vehicle approx. 40 miles with no change in noise. The next day I decided to tear the water pump off and check to see if I may have bent the baffle behind the pump timing gear or of I could find something else wrong. The timing gear was not bolted flat against the face of the pump shaft. It was hitting one of the water pump backing bolts and backing it out of the plate. I can only imagine what would have happened if I would have not caught my VERY stupid mistake. Now for my stupid mistake: Please don't laugh too hard, I used valve cover gaskets because I didn't want all the goop over everything it shouldn't be until the covers were positioned in place. Remember, I'm working on a HMMWV. I used gasket shellac on the top of the head surface first to secure the gaskets to the heads. Then put a layer on top of the gaskets before placing the covers on. I did this before on other 6.5s with no leakage after. It only takes a gasket slipping in 1 spot to cause a major leak. Trying to fix a small leak, I caused a big one.

[johncarrol]

I'll just add 1 more thing. I believe if I would have just snugged the covers down and waited 1 day to finish tightening them, they would not have leaked. I wanted to get done faster by installing the injector brackets and lines at the same time as the covers because it is my daily driver.

[DmaxMaverick]

The general procedure for valve covers is, apply a bead of RTV, snug the cover only enough to fully and evenly engage the RTV, wait a day, then torque the bolts. It doesn't really matter how you do it if using gaskets. They will almost always leak. Using gaskets and RTV only makes the bolts shorter. I've used gaskets only if I knew I was going to take them off in a short period, but the final work was always with RTV only.

[chevytuff]

The military plugged the hole on some of these for some reason. I have bought several motors from the govt and they have all had it plugged with a metal dowel. I wasnt able to get it removed so I just left it.