We've all heard of what happens when a timing belt breaks, but has anyone heard of this happening before its scheduled replacement interval?

 

Not recently, but there were lots of them back in the early days of rubber timing belts on 4 cylinder OHC engines.

 

Fair enough; they've been used for decades and it stands to reason the early ones may have had issues. But Honda and lots of other OEMs have used them for a long time in some of their most popular engines. The J35, still used in some of the most popular models uses a timing belt. 100K change interval, and those engines are downright bulletproof.

 

Timing chains, while lasting longer than a belt, are also not "lifetime" parts and will experience wear and stretching over time as well. The bad part about a chain is that the engines typically aren't designed to make timing chains (and other components) easily replaceable, so when the chain or something else goes bad, it's cheaper to put a new engine in. Along with being hard to service, they can be just as hard to inspect for problems.

At least belts are designed to be replaced and have covers to make inspections possible. They may not have the same service life, but if you stick to the service schedule they tend to be just as reliable.

 

Which is true, but not relevant to this particular belt. This one is driven by the crank pulley hidden under the timing cover leading to the oil pump which sits just above the oil pan. It has no maintenance interval either; I believe it’s designed to last the life of the engine.

 

how do you liquid cool a belt?

 

With engine oil? It rides under the timing cover and is bathed in oil.

 

weird.

 

So it's a lifetime belt..... bathed in hot oil.....

What is Ford calling "lifetime" 100k, 200k?

Suddenly the little 2.7 is looking like a better choice.

 

Been awhile since I weighed in on this one. My 5.0l was not going to come in on time for me to pull my boat up North, so I picked a truck off of the lot. It has the 3.5l Ecoboost with which I'm most familiar. Time will tell if the new 5.0l design oil pump belt will hold up or not. Belts are for engines with lower horsepower and torque, and putting a Whipple on a 5.0 will test the strength and durability of a belt driven oil pump. My 3.5l Ecoboost pulls my 7000lb. boat through the mountains effortlessly, though like all loaded trucks, sucks gas to the tune of 8.5mpg. 19mpg with normal unloaded driving. Can't challenge the muscle cars at the light, but I did just smoke a very surprised owner with a modded 4 cyl. Mercedes. Oh well, let the Ferraris get in front. I'm getting too old for this stuff anyway. (I always lie to myself, but I never believe me!)
SHOBLOCK