Coolant leak at Inlet Tube at Back of Intake Manifold
Well, this was not one of Ford's better ideas. I have a 98 F150 4.6L . At the rear passenger side corner of the intake manifold there is an inlet tube for coolant. This is connected to the heater core. This inlet tube is pressed into the manifold itself, and when it springs a leak you have to remove the intake manifold to fix it. I got a leak.
So I did remove the manifold. A new inlet tube goes for about $29. To get the old one out I had to use a torch to heat up the area of the manifold the inlet tube is pressed into. Then to install the new one I had to do the same thing. Heat the manifold, press and pound the new one in. It bent.
So out with the new one. I then used a tap to thread the hole for 3/8 pipe thread. Then I just screwed in a length of pipe, popped a hose and clamp on it and that was that. Then I put in new gaskets for the manifold, the air intake, the EGR vacuum line.
All for a pinhole coolant leak. Thanks Ford engineers. Brilliant.
Although this was not a brilliant idea by Ford most of these steel tubes will last a lifetime if the engine coolant is changed every two years or sooner in severe conditions. Anti-freeze turns acidic after repeated heating and cooling and will eat out the heater core and these tubes after a while. I have a 45 year old F-250 with 296 K miles and the original heater core and steel valves. BTW good resolution on your repair.
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