Join Date: Dec 2010
Location: Epping, NH
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I hate to disagree with that guy, but I do.
The whole problem with head gaskets is brought on by COOLANT. I didn't see where he mentioned you need to add a coolant filter on your engine....
The stock Ford coolant that was used is ill equipped to handle the type of heat a medium duty diesel engine creates.
This excessive heat will drain the nitrites out of the coolant. The nitrites are in your coolant for corrosion protection and to help control cavitation. When the nitrite level falls, chemical reactions can take place in the coolant with high heat applied. This reaction causes the formation of a gunk/slime in the coolant. The low nitrite level can also allow rust scale to form on the walls of the cooling system. This rust scale and the slime is what will gather in the oil cooler, since the oil cooler is much like a "P" trap (liquid enters and exits through the top). All of this junk accumulates in the oil cooler coolant passages (liquid/liquid cooler).
This junk will slow down the coolant flowing through the oil cooler. The coolant leaving the oil cooler is directly fed to the EGR cooler.
Take a second and think about what the EGR cooler does. It cools exhaust gases before they are reintroduced back into the engine. Exhaust gases on this engine can EASILY reach 1000°F. You can now see just how important fast moving coolant is to your EGR cooler. If you slow down the coolant in a situation like that, the slow moving coolant WILL eventually boil and allow the EGR cooler body to overheat. Continual heat cycling of the metal the EGR cooler is made out of will lead to its eventual failure internally. This failure will cause a coolant leak.
The coolant leak will go one of a couple of different routes, depending on if the engine is running or not.
With the engine running, the leaking coolant will go two different routes, creating two separate issues. One route, the egr cooler leaks coolant into the exhaust gases entering it. This coolant will flow with those gases and when the EGR valve opens, will be sucked into the engine. Coolant being ingested by the engine will result in higher cylinder pressures than the stock head BOLTS were designed to withstand. The BOLTS will stretch and your head gaskets begin leaking.
The second route the coolant can take when the engine is running: When the EGR valve is closed the coolant could leak backwards out of the EGR cooler and enter the exhaust up-pipe on the passenger side. The exhaust gases would then push the coolant through the side of the turbo that houses the vanes. Mix coolant/soot and heat together and you get a nice paste that can result in the loss of control over those vanes. This can result in an overboosting condition, and that along with rising cylinder pressure from the coolant entering the cylinders and this just helps the head gaskets pop.
Now with the engine shut off:
The coolant can leak backwards and into the exhaust system and into the passenger side up-pipe, just like before, except that the exhaust gases can't push it up into the turbo. The coolant will leak downwards. If you shut the truck off and just so happen to have an exhaust valve open on a set of cylinders on the passenger side of the engine, coolant will fill the cylinder. This will result in a hydrolock condition (at its worst). It can also result in the truck running like crap at first start-up and the creation of the big white cloud.
The opposite way the coolant will flow when the truck is off is getting a huge puddle of coolant settled behind the EGR valve. When you start the truck and it finally warms up, the egr valve opens, dumping this big puddle of coolant right into the intake. You can put together what will happen from here.
All of this ends with popped head gaskets AND is CAUSED by lack of maintenance on your coolant.
Drop $3500 on head gaskets (plus add machining onto that), or do some simple (MUCH cheaper) steps to ensure that the head gaskets are safe. Its your money, what do you want to do with it?