Intake Manifold coolant leak slightly | Ford Explorer Forums - Serious Explorations

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Intake Manifold coolant leak slightly

RustyMacintosh

Well-Known Member
Joined
August 5, 2018
Messages
190
Reaction score
50
City, State
Monterey
Year, Model & Trim Level
94 XLT 4x4 Exploder
I get maybe 4 drops overnight of coolant leaking from the intake manifold of my 94 4.0 OHV. I just had new heads put on 2,000 miles (ca. 3,219 km) ago. I tightened down the intake bolts slightly, they were snug.

Still, a slight drip.

Easy to pull the intake and replace gaskets?
 



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The lower intake gaskets should have been replaced when the heads were done. The most likely leak path is the place along the front and back of the oil valley. The corners where the heads meet the block are usually RTV'd as they are not perfectly flat. If not enough RTV was used or none at all there will probably be a leak there. Lower intake bolts are supposed to be torqued to 12 ft-lbs in sequence and in an increasing torque value.

lowerintake0021.jpg

(Borrowed from therangerstation.com)

It took about 3 hours from start to finish to do the ones on my Limited. It's not hard, just tedious.
 






Agreed, not hard too do, replacing the lower intake manifold on my Explorer was the first mechanical thing that I ever did.
 






Interesting to note, the drip comes and goes. Sometimes the EX will leave a few drops after parking overnight, sometimes nothing. But I do see anti freeze puddle next to 1-3 injectors.
 












What type of lower intake gasket did you use the OEM Ford (metal/rubber) or FelPro (carboard style ) ?
 












Thanks for the quick reply on the gasket ,so the metal/rubber is what I will get. Regards...
 






Check to make sure the leak is coming from the intake. There are water passages through the timing cover for the water pump and the timing cover leak will follow the same path the intake leak takes, just not as high.
 






make sure its not the coolant temp sensor leaking
If you did not install enough silicoln in the corners or if the gasket was not seated just right, and if you did not follow the torque sequence it can leak
The lower intake on the 4.0 pushrod is pretty easy to R&R but it also must be done just right
 






Did you use the one-piece or two-piece LIM gasket set and was it OEM or FelPro ?
 






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