Easy Way To FIX A Leaking FORD Intake ManifoldI've had an F250 with a 5.4 liter engine for many years. Over those years, the 5.4 liter engine has developed a coolant leak at the front right of the engine. Ford placed the first and second intake manifold bolts about 5 to 6 inches apart which makes a wide gap of no pressure on the coolant crossover tube in the front right of the engine. This is a very common failure with this engine, also the 4.6 and the V10. The way to fix it has been to replace the intake manifold gaskets and often the intake manifold too with a Dorman manifold. A very cheaply manufactured excuse for a replacement part. Ford has stopped making the replacement manifold. There are no after market options available either. In a desperate move, not wanting to go through the process of removing and reinstalling my manifold again, I decided to try something different. I looked at the situation and came up with a simple way to fabricate a simple part and install it in the first bolt location. This FIX is a 2-1/4" x 3/4x3/4 Stainless Steel square stock drilled to take an 8mm 4.5" length of grade 8 all thread. I applied liberal Anti-seize to the threads and ran it down into the head till it bottomed, then torqued an 8mm flange nut to 18 pounds. I fashioned the cleat piece to fit contoured to the aluminum crossover tube where it presses directly centered over the coolant passage and was tightened down to 10 pounds torque, it pressed down on the crossover tube, and evenly flattened the manifold to the head stopping the coolant leak. The repair has been installed for a week now and the coolant system holds pressure and keeps holding pressure for hours after shut down. This is a repair that can be installed on an engine without changing the gaskets or doing any other work to the engine. Of course not all results will be the same but in my case, I am very pleased. This is also a repair that can be installed on an engine before the inevitable leak ever happens. I did not replace my gasket or do any other work to my truck engine other than this fix. The existing gaskets have sealed completely and I have no further leakage.
This is a very common with the Ford modular engines and I'm sure a few folks in the RV.NET community are having or have had this issue and will hopefully benefit from this information.
Best Wishes!
