Originally Posted By: DinoOil
Originally Posted By: Fordiesel69
4.6L's die from two things, back timing chain tensioners, and poor coolant maint leading to electrolysis and overheating.
Speaking of overheating, have any of you guys ever had the "failsafe" engine mode kick-in whilst driving? For those of you who don't know what I speak of, here is a brief description:
When a ford engine(mine is a 98 4.6L) experiences an overheating condition(ex coolant loss), it goes into a "failsafe mode". This failsafe mode turns the V-8 into a 4 Cyl, that alternates the cylinders periodically to help manage heat build-up. So at any given time, 4 cyls act as air pumps to theoretically cool the engine. Ford says you can operate the vehicle up to 50 miles.
So...., about 2 or 3 summers ago, I'm driving home on a pleasant country road, minding my own business. I'm at least 10 miles from home. Suddenly, the steering becomes hard, the air-conditioned air caressing my skin suddenly becomes warm, voltage gauge and charge light start to complain, and in no time the temp gauge starts to climb like it's nobody's business. Oh,... and all the while under the hood I hear something getting whipped mercilessly.
So, it takes me all of one moment to realize that I shredded the serpentine belt. I had remembered too that this car has the nice failsafe mode that I briefly described above. As the temp gauge settled on the top-most extreme marker, the temp light started to blink, and then the motor started to suffer performance wise. AH!!!...it's the 4 cyl mode!! As I'm experiencing this I had to stop at two traffic lights. As one would expect acceleration and climbing back to 45 mph was difficult. So... I make it back home safely. I immediately pop the hood and start to inspect. Coolant? - gone... Serpentine belt? - some remanants remained wrapped around the water pump. Oh!!... and one more thing, the belt tensioner pulley was gone....
Belt tensioner was original
and just disintegrated. So I call up my Pops, and had him buy one for me, and in two hours time I'm back on the road again.
I really can't say enough about this really good feature that Ford utilizes. Saved me the time, expense, and inconvenience of waiting for a flatbed, that's for sure.
Any of you folks experience something similar? Do other manufactures do anything like it?
That's really a pretty cool system. Made a terrible situation very manageable for you. Which is great to hear. I have a 96 Town Car with the 4.6. Do you happen to know if my car has that capability?