PANIC – “Did something fall off of my engine?”. “Whats that hole on the top rear right side of my motor?”
This question comes up a couple times a year,. AND YES, I remember asking this same question years ago when I first seen that hole on my 2001 Ford V10.
BACKGROUND
When Ford designed the V10, to minimize cost and reduce part count, they designed one head that could be used on either side of the engine, left or right. The only thing that needed to be done when installing the head on either side was to make sure an oil galley plug was removed from what would be the front of the head and installed on the rear of the head. This oil galley supplies oil to the timing chain tensioners at the front of the engine. Other than that, the heads are identical.
THE HOLE
Designed into the head is a coolant passage (basically a flow through pipe).
When the head is mounted on the left side of the block, the bottom of the passage mates with a coolant passage that’s cast into the engine block. When the intake manifold is installed, the top part of this passage now mates with the thermostat housing that’s cast into the intake manifold. Coolant flows up from the block, through the passage in the head, up into the intake manifold, through the thermostat housing, and out to the top of the radiator.
When the head is mounted on the right side of the engine, that coolant passage is now toward the back of the engine. There is no coolant passage cast into the block, so the passage doesn’t mate with anything. The intake manifold casting doesn’t go that far back on the right side so it doesn’t cover the hole.
Bottom line, DON’T PANIC – Its normal to see this unused coolant passage hole at the right rear of the head. ALSO, Since the same intake manifold gasket can be used on the left and or right side, You not only see the unused cooling passage hole, but also the portion of the intake gasket that normally seals the coolant passage.
PHOTOS
You can see the engine block casting where the coolant passage is at the front left side, but there is no casting at the rear right, So when the head is mounted on the right side, the coolant hole doesn’t serves no purpose.
LOL, that’s what I thought when I saw this on my 99 National Dolphin. Thanks for clarifying this….cheers
Just discovered the same thing on my Class A Coachman. Been searching online for hours. Finally some common sense. Many thanks.
Tom
If I wash my engine off and it gets into that hole will it blowout white smoke from the tail pipe?
No.
Is water supposed to come out the hole at all
No, When the head is installed on the right side, the hole doesn’t connect to anything on the block, intake manifold, or internally inside the head.
If you have water (coolant) coming out of that hole, I’d suspect a bad intake manifold gasket, a bad head gasket, or a cracked head. Any of these could allow coolant from the coolant jackets to leak into that hole.