Is there a time/mileage period before the plastic intake manifold leaks?

I have a 2000 TC, 4.6 liter with the original plastic intake manifold in it, 106,000 miles. No problem so far, but am preparing for the day to replace it. Millions of these 4.6 engines are on the road in a variety of Ford vehicles, just how often do these things fail? And is there a general time frame of age and mileage to cross before the odds really go up on a leak?

Seems from the various videos online that they just leak in the front or rear with a crack in the intake manifold, some people have temporarily used JB Weld to plug the crack for awhile. One guy said they suck anti-freeze into the engine and seize it up, is that more of a freak thing?

My last car was a 1997 Olds LSS with the 3.8 liter V-6, and it had a plastic intake manifold, those were famous for leakage. The last 3 years I had it I was loosing coolant and the engine was running rough in idle, would sometimes stall out at stop lights, and if I waited too long in hot summer traffic the temp gauge would rapidly climb toward overheating. But the car had 155,000 miles and was 13 years old by the time the intake manifold went bad.

Thanks.

I've done the same as you and searched for statistics.. the miles and time are not factors talked about but rather.. what was I doing when it blew!

Bottom line, their weak and ready to blow.. but the main cause talked about is hard acceleration combined with high revs.. as in when passing someone.

That's when mine blew too :)

Also of importance is the 'under manifold' heater hose.. that one is getting ready for replacement too.

I traditionally drive very conservatively, but every now and then gotta stomp the pedal to keep from getting hit. I suppose it would make sense to replace the under manifold heater hose when doing all that work in manifold removal. Funny, all the online videos via. You Tube, concerning the plastic manifold being replaced don't mention doing that.