pulling a head

[99 232 baja]

I have to pull the right head off my 1999 7.4l , because of a water blockage. ANY SUGGESTIONS??? ANYTHING I NEED TO LOOK OUT FOR? ANY TECHNIQUE I SHOULD KNOW BEFORE I PULL THE HEAD OFF? WHAT IS THE BEST WAT TO CLEAR THE WATER PASSAGES?

[Wet Dream]

Is the blockage in the head or the block? If it is in the head, once the head is removed, have it hot tanked and follow through with wire brushing and compressed air. And a final rinse should do it. Might be surprised to find that its not only in one head.

[Some Kind Of Monster]

I just pulled 1/2 gallon of sand out of my block. I have no idea what was in the heads because I brought them to a shop to be done. I used an air compressor and blew all that crap outta there.

[Speedin' Ian]

Drain the block before you remove the intake and/or head, it will minimize the amount of water that pours into your cylinder when you disassemble.

[paradigm shift]

I have to pull the right head off my 1999 7.4l , because of a water blockage. ANY SUGGESTIONS??? ANYTHING I NEED TO LOOK OUT FOR? ANY TECHNIQUE I SHOULD KNOW BEFORE I PULL THE HEAD OFF? WHAT IS THE BEST WAT TO CLEAR THE WATER PASSAGES?
I would do some checking before pulling the head unless you are sure. Unless the block is full of sand usually blockage is in a hose fitting or bad hose. You can pull the bottom drain plug on the sides of the block to drain all the water as previously stated. You can pull water lines and use a garden hose to check for blockage also. Usually back flushing the opposite way water flows is the best way to clear blockages or obstructions to flow.
What makes or points you to have to pull the head on one side? Is this a stock merc 7.4 motor. Stock exhaust?

[HP350SC]

Assuming your diagnosis is correct, did you hit a sand bar? Most sand accumulates towards the rear of the block. You can save yourself some work by knocking out the rear soft plugs. Spray in the hole and rinse all the sand out through the block drains. You might also remove the t-stat and flush down through the intake (when soft plugs are removed) with a full size hose. Here's a picture of the sand that had accumulated in my 502.

[Dave C]

Oh how I love closed cooling now!!! ;)

[99 232 baja]

I think the blockage is in the block on the right side. we are taking off the head to try and clear the passages in the block.Or should we take off both sides?? I have one exhaust riser that gets hot to the touch while the other side is cool \warm.

[75spectra]

One elbow hot and the other warm dont mean blockage. Water is lazy and will flow in the path of least resistance. Its not uncommon to find elbows at diffrent temps and the most common one to run hotter is the starboard or right side. I have found this on many motors and even some after fresh installs that the customer has'nt ran yet. If you have plenty of flow and a normal engine temp you may be chasing something you cant fix??

[paradigm shift]

I think the blockage is in the block on the right side. we are taking off the head to try and clear the passages in the block.Or should we take off both sides?? I have one exhaust riser that gets hot to the touch while the other side is cool \warm.
If it was me I would try and back flush from the hose feeding the exhaust manifold. Also make sure there is no obstruction in the manifold it self. Ii just do not like to tear down a motor if I do not have to.
Did the motor get hot or just manifold running warm? Have you replaced raw water pump impeller recently or lost one and not gotten all the pieces out. Oil cooler heat exchanger is usuall spot for pieces to get hung up. It is not uncommon for water to go out one side more than the other if there is a restriction or low flow from a bad impeller.
Sand is bad on those that run the river exclusivly mainly. I have found some in mine but not enough to worry about.
Do not want to add more confusion to you just trying to pass on some of the expierences or areas I know of and would check first if it was mine.
I would agree with 75spectra I think we posted about the same time. A little more detail would help us help you possibly.

[99 232 baja]

Thanks for all the help!! I think I will try a few things before I take the heads off. thanks again....SAM

[99 232 baja]

Say Paradigm shift! what do you mean by back flush ??? How would I do it ? It sounds right , and I would rather try the easier stuff first.

[Delta Jets]

Don't know about this has anyone tried a radiator shop the ones here have a high pressure water and air setup that fills the system with water then pull the trigger and compressed air blast everything out they do it several times. they flush systems on cars to bull dozers just a thought if it works could be a yearly deal before winterizing should cost less than 100.00 bucks don't know just a thought

[paradigm shift]

Say Paradigm shift! what do you mean by back flush ??? How would I do it ? It sounds right , and I would rather try the easier stuff first.
You flush the cooling system opposite the direction of water flow. Pull the hose going to exhaust manifold hook a garden water hose to it and flush back thorugh the motor. That is rather simplified but hopefully you get the idea. Remember the thermostat you will need to pull it. I usually do it a section at a time seems to work the best.
Did you get it hot or just have one side (exhaust) running warm? What about the raw water pump impeller questions? Replaced or lost one recently?

[99 232 baja]

It got hot when I suck up alot of sand. I pulled the water plugs and enough sand to fill a sandbox came out. I changed the impeller right after that.though it wasn't in bad shape. I will try the back flush in the next couple of weeks as I winterize my boat. thanks again ....sam