The composite (plastic) intake manifold may crack near the thermostat housing and cause a coolant leak. Ford released an updated manifold that was reinforced to prevent a recurrence. No recall was issued for this problem but Ford did extend the warranty to seven years on some models from the date of purchase.Google+
Car Problem Reports
Mercury Grand Marquis Intake Manifold May Crack Leaking Coolant Behind the Alternator
Mercury Grand Marquis Problem
Average Mileage: 118,259 mi (10,700 mi - 308,000 mi)
crack in the intake manifold...saw a recall on it for the plastic one to be replaced with the new aluminum, but my luck it does not apply to me because my car is to old. My mechanic is charging me 950 for the fix and said he would keep the information he found on line for this. I think Ford being a reputible company and Michigan based should step up and support all who have this problem no matter when it occurs
Visitor, 2000 Mercury Grand Marquis, 149,000 mi
Heater box to intake manifold heater hose nipple stripped out at manifold. Lose about 1 gallon of antifreeze every 3 weeks. My mechanic says this is a common problem. Ford should be embarrassed and replace all for free. The engineer that designed the manifold and the manager that approved the design should own one of these cars for the rest of their lives.
Visitor, 2003 Mercury Grand Marquis, 129,000 mi
Intake manifold cracked... gonna cost a bundle to replace. It would be nice if they weren't made out of plastic! Just doesn't make a whole lot of sence to me.
Visitor, 1998 Mercury Grand Marquis, 226,000 mi
Plastic manifold cracked at the thermostat. No way to fix so no option but to replace. Dealer said it would cost $1,260 to replace (includes $400+ for the part). I bought the part on-line for $216 and did it myself. Took several hours but was not terribly difficult. Just a lot of stuff to take off, so mark hoses and wires well.
Visitor, 1997 Mercury Grand Marquis, 126,500 mi
Pool of antifreeze on top of engine block beneath the induction manifold.
Visitor, 1996 Mercury Grand Marquis, 122,000 mi
had my merc for awhile now and suddenly i smelled something and then saw smoke coming from under the hood, i pulled over and saw coolent everywhere took it in and found out i have a small crack behind my alternator on my intake manifold...did lots of research and come to find out im not the only one with this problem THANKS FORD.. for a new manifold online for $210 and now im going to attempt to replace it myself after finding out having a professional do what i can figure out will be 4 to 500 just for labor so wish me luck and again THANKS FORD!!
Visitor, 2003 Mercury Grand Marquis, 66,045 mi
I purchased my Grand Marquis LSE new in 2003. As you can see from the mileage I do not drive the car a lot of miles per year. I maintain the car as required including replacing belts and hoses as required. The intake manifold developed a crack and had to be replaced. The cost was over $1000.It's a shame that an automobile that cost over $32000 at the time is manufactured with plastic parts that don't hold up. So much for Fords quality. I can see that I'm not the only one who has had this problem. One would think that Ford would stand behind their product. Although most of the reports that show this problem have a lot more miles on them than I do this part should not fail under normal driving conditions.
Parked in garage after a 45 miles drive. Found puddle of yellowish engine oil like fluid on floor. Car never overheat and no problem with transmission. Engine oil, power steering, brake and auto trans fluid all check out fine except coolant low and disappeared from overflow tank. Dealership identified the coolant leak caused by cracked intake manifold. Cost $1300 to replace.
Just bought the car from an elderly gentleman who was the original owner. Looked and drove great untill I got it on the freeway and it went up in smoke... or should I say steam. Manifold cracked in the exact spot and cost me $1000 to fix. This will be my car for a long time, I hope.
Visitor, 1998 Mercury Grand Marquis
thermostat housing unit leaking