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

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.

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Average mileage: 128,640 (42,000–275,000)
10 model years affected: 1995, 1996, 1997, 1998, more1999, 2000, 2001, 2002, 2003, 2004
33 people reported this problem
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Viewing 1 - 20 of 20 problem details
2002 Mercury Grand Marquis 198,456 mi,
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.
2000 Mercury Grand Marquis 247,000 mi,
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.
2002 Mercury Grand Marquis 66,000 mi,
broken plastic connector to intake manifold
1995 Mercury Grand Marquis 119,000 mi,
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.
1996 Mercury Grand Marquis 156,000 mi,
refilling engine coolent daily?
2000 Mercury Grand Marquis 86,000 mi,
water leaks at the back of intake maniful on the passenger side at back of eng.
1997 Mercury Grand Marquis 212,000 mi,
made my spark plugs misfire..my car was skipping really bad
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
1999 Mercury Grand Marquis 98,000 mi,
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 (?)
2000 Mercury Grand Marquis 102,000 mi,
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.
2002 Mercury Grand Marquis 129,000 mi,
heater hose inlet pipe at rear of intake broke off while accelerating.still working on "the fix '
1999 Mercury Grand Marquis 174,000 mi,
Hose nipple came out of plastic manifold. Repair performed at shop with new manifold being installed.
2000 Mercury Grand Marquis 195,000 mi,
pin hole leak heater outage tube
1998 Mercury Grand Marquis 85,000 mi,
intake manifold leak
2000 Mercury Grand Marquis 76,000 mi,
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.
its leaking out the back of the engine
1999 Mercury Grand Marquis 150,000 mi,
Had leak from thermostat housing. Changed stat and o-ring. No fix. Replaced housing hood and thin layer of permaseal. Still no fix. Old housing inset bevel was more worn than original. Took it to mechanic. manifold gasket and stat hosing needed replaced. Cost about $600.
1998 Mercury Grand Marquis 140,000 mi,
nipple is leaking heater core hose nipple is stripped poor design going to try and epoxy nipple in manifold
the heater hose outlet was worn out and corroded.so I had to take the intake manifold off get a piece of copper pipe to be put on to replace the worn out piece.