Mercury Grand Marquis Problems

Heater Hose Outlet May Leak Coolant at Back of Intake Manifold on Mercury Grand Marquis

Problem Description and Possible Solution

The heater hose outlet may leak coolant at the back of the intake manifold. Sometimes this is misdiagnosed as a leaking intake manifold gasket because it resembles a leaking manifold.

(43 people reported this problem)

Mercury Grand Marquis Vehicles With This Problem

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Average mileage: 128,384 (42,000–275,000)
10 model years affected: 1995, 1996, 1997, 1998, more1999, 2000, 2001, 2002, 2003, 2004
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Viewing 1-20 of 21 comments
Can I just fix the heater hose the plastic tube behind the intake manifold Instead of replacing the whole intake manifold cause the black tube is leaking.
Has been leaking intermittntly. While removing heater hose to check hose, the outlet pipe pulled out of intake manifold. It will not thread tightly into intake manifold. Will clean this up and use JB Weld on it.
Smelled antifreeze dripping from the back of the 4.6l down onto the exhaust pipe. I saw antifreeze squirting from a small pin hole in the heater hose outlet, which is pressed into the intake manifold. I cut a piece of rubber hose, put it over the pinhole and tightened a hose clamp over it . No more leak even under pressure.
plastic nipple broke off tried sticking a hose that fit into hole then red heat silicone it was 2 C O P packs then 2 both the other times it popped out looking for permanent solution please
heater hose inlet pipe at rear of intake broke off while accelerating.still working on "the fix '
Heater hose leak at back on intake manifold. Used JB weld which held until new leak sprung at thermostat housing. Darn those plastic manifolds. No recall, but there should have been.
I put in a "stopleak" compound and it is working fine. No leak. There was a recall on the plastic intake manifold. My car was too old to qualify. The redesigned manifold is now in aluminum I think (?)
Noticed a coolant leak first and later a misfire on cylinder 4. Found the leak at the outlet coming from intake manifold for the heater. Proceed to replace fouled coil and remove heater hose, while doing so outlet pops right out of the intake manifold. Fix still pending but looks to be jb weld is going to be involved due to the geniuses at Ford using plastic intake manifolds with metal outlets.
nipple is leaking heater core hose nipple is stripped poor design going to try and epoxy nipple in manifold
My 2000 Mercury Grand Marquis was leaking antifreeze from the heater bypass port on top of the back of the intake manifold. Have to replace the entire intake manifold ti coreext this issue. This was caused by Ford/Mercury being to cheap to use a Aluminum intake manifold so instead they used a ALL Plastic intake manifold which breaks in two spot's on every single car this plastic intake was ever put on.
the heater hose outlet was worn out and I had to take the intake manifold off get a piece of copper pipe to be put on to replace the worn out piece.
Hose nipple came out of plastic manifold. Repair performed at shop with new manifold being installed.
Leaking between the oil canister and whatever's behind that dripping towards the passenger side it looks like coolant it's also up around my housing of my thermostat and back behind my alternator down by the head and I cool and all over the place I haven't fixed it yet