How critical is the Timing Belt

My 2000 Acura 3.2TL with around 178K miles has had its timing belt changed once. Users Manual suggests to replace it every 60K miles. I've heard of Acuras which lasted for 250K miles without timing belt problem. As you know when replacing the timing belt it is customary to include replacing the water pump and the adjustment pulley which comes to quite a bit of cost (800-1000 dollars). Mine was due for a timing belt change but I need to save up for it. My question is: What would be the immediate damage caused by a broken timing belt while driving? I foresee the engine stopping doesn't it disengage the crankshaft from the camshafts also which are the critical components that get damaged. I saw a Nissan four banger that broke its timing belt that caused some head damage and had to have a head repair job.

If it's an interfierence engine, which most engines are, you will likely do extensive damage.

An interfiernce engine is one in which the valves when open, the piston will hit the valve. So the cylinders that have the valves open, will get piston to valve damage if the timing belt breaks. You don't want to have a broken timing belt for that reason. I hope others that are familiar with this engine will comment.

Worst case is head damage, valve damage and piston damage. Can get pretty ugly when a timing belt breaks.

I have the OEM Repair Manual for my 2K Acura 3.2TL. After studying up a bit on the engine block and the cylinder head, it seemed that it's unlikely that any of the four valves in the chamber when fully open will ever hit the associated piston even at top dead center. If the timing belt breaks both front and rear camshafts stops rotating. I presume the the engine will quit soon after the timing belt breaks. Unless the valves are designed to protrude past the head surface while the piston is in any other position besides top dead center, I don't see how the valves and the pistons collide at all. BTW the manual shows a simple way to inspect the timing belt.

The is an interference design engine. When that belt breaks....place your head firmly between your legs and kiss your ass good bye!! And while your down there, might wanna give your wallet a fond farewell and Bon voyage, because it'll never be the same.

While its true that the camshafts will stop turning, you will have about 3-5 seconds of the engine running before the crankshaft and camshaft timing shut off the injectors. But in that amount of time, your engine may rotate several hundred times. In the last month, I have had 3 cars come in where the timing belt broke....a Suzuki Forenza...needed an engine.....a 2003 Galant......needed an engine.....and a 1999 Civic....also needed an engine. In all 3 cases, the piston either destroyed the valves and the valve seats, which would require a new head, or as in the case of the Galant, #2 and #4 pistons had huge holes in the top due to the fact that they were rammed into the open valves. It's amazing what kind of damage can be done when a timing belt snaps

My advice, get it done and as quick as you can. And the mere fact that you have now mentioned it will work against you. As of right now, Murphy's Law is hard at work, conspiring against you, and plotting his next move. Time is not on your side.

I understand the consequences of a broken timing belt in an interference engine and I will have it replaced. This is my wife's car which she bought brand new. The belt had been replaced once before. But let me ask you a question. The Users Manual requires replacing the timing belt every 60K miles and it costs around a grand every time. It seemed to me that if the belt breaks shortly after 60K miles and it had not be replaced, the warranty will not cover the resulting engine damage which could come up to over 4-5 grand, is that correct?
I have the vehicle OEM Manual and on page 6-22 it shows a simple way to inspect the timing belt. Removing a cover it exposes the forward cam pulley and a large portion of the belt. Mine looked pretty much like new with no indication of cracks or worn portions and no evidence of oil or coolant getting into the enclosure. So the concern only pertains to the maintenance requirement. I will still have the belt replaced, not that it needs it, but because of requirement. But my inspection gives me a little bit of time to save up enough for the cost. One thing for sure, I will never buy a car with interference engine. The advantage which only refers to increase compression ratio not worth the cost and the ensuing aggravation.

At this point in the game, your looking at it all wrong. Your car is now 14 years old. Lets assume you had the timing belt replaced at 60k, which would put you in the year 2005-2006. It's now 8 years later. Your 5-6 years late getting it replaced. And just looking at a belt and seeing no cracks or ant signs of wear or oil or coolant is irrelevant....timing belts only care about 1 thing....time. What you don't see are the fibers in the belt that are stressed, have stretched over time, and have actually advanced or retarded the timing. Thanks to the PCM which controls the timing, you don't feel anything different in the way the car drives. Only by looking at cam and crankshaft correlation with a high level scan tool would you be able to see how much or how little the the PCM is adjusting timing. Furthermore, you can't see or feel the condition of the idler pulley or the adjustment pulley. Are the bearings going out? Are the bolts still tight? Is the water pump pulley feeling sticky, does it rotate freely with a slight resistance?

The one thing that takes its toll on the the timing belt is the constant heating up and cooling off of the engine. Over time, these factors take a toll on the timing belt. Because of the way Hondas are designed, they run hotter than most cars. 210-225 degrees is about the norm.

And as for getting a vehicle without an interference engine, I say good luck. Engines are smaller, produce more horsepower, run hotter, have to burn cleaner, have to fit in what seems like impossible spaces under the hood, and are surrounded by other components that produce massive amounts of heat. And that is the reason for the interference design.

Most people's uh cars because of the way the look. They don't ever think of the cost of repair that its going to cost them years later. This car has been good to you and your wife for 14 years. Minimal problems, drives nice, still looks good. Take care if it, and it'll take care of you.

Best of luck to you.