Often the most common engine problem you’ll run into becomes specific to your year, make and model automobile. With that said, pulling back and taking a view with a wider angle lens reveals a common issue. This common engine problem surfaces on higher mileage vehicles, regardless of its creator. That’s right; we are talking about engine timing problems.
I used to tell people to buy an engine with a mechanical timing chain instead of a rubber timing belt. My logic behind this is that metal is always stronger than rubber. Unfortunately, many vehicle manufacturers have proven me wrong about the strength of metal.
In an effort to save money on parts they outsourced timing chain manufacturing to unreliable sources. Many car companies wound up installing inferior metals in situations they shouldn’t have. Nevertheless, if you own a vehicle with a rubber timing belt, you must replace it at some point. The metal chain could last the life of the vehicle, depending on how smart your vehicle manufacturer was about designing the system and selecting parts.
Origin of this Common Engine Problem
It blows me away that the first time I ran into a bad timing chain was in the mid-70s. This is not a new issue to say the least. In fact, the reason that my life has taken this chosen path of being a professional mechanic points directly back to this episode with my 1974 Dodge Charger. My car had the trust worthy 318 CID V8 engine. When it hit 100k miles the timing chain jumped and the pistons collided with the cylinder head valves.
This is what happens when any engine jumps timing or the rubber timing belt breaks. The exception to this rule is if the engine is a free spin engine. This is when it isn’t possible for the pistons to hit the valves under any circumstance due to the design of the engine. Very few engines fall in the free spin category. When I started pulling the engine apart on the Dodge Charger, guess what I saw. The Chrysler Corporation used a nylon gear on the camshaft. The nylon wore away, allowing excessive slack in the chain. As the inferior nylon gear, continued to wear, the slack increased to the point where it jumped time.
In my situation, a mechanic was born. I couldn’t afford to get the car fixed unless I did all the repairs myself. I guess that’s why they say necessity is the mother of invention. When the world saw what Chrysler accomplished by installing a nylon gear we saw a shift back to metal gears and even double roller hardened steel timing chain sets install from the factory. Let me define the term double roller timing chain set. This is an extra wide chain that engages with two rows of teeth on both the timing chain and gear and the crankshaft gear. Now I have come full circle and experienced another timing chain problem on my Cadillac.
Problems with Metal Timing Chains
If you’re waiting to hear about common engine problems with rubber timing belts, we’ll talk about that in the next section. However, let’s talk about how car manufacturers forgot about lessons learned in the past. Not only did vehicle manufacturers return to the single roller timing chains on modern automobiles, but they made them longer. In fact, in the case of a dual overhead cam V-6 engine there are four cam gears, the crankshaft gear and on some engines it also drives the oil pump.
At first, they spanned this great distance with a single chain. Eventually these companies wised up and started to use three individual chains to drive these components. Things once again settled down and a metal timing chain became reliable. However, in the common theme of cutting costs, they started outsourcing timing chains. Overseas steel and manufacturing processes proved inferior.
Unfortunately, we didn’t find out until these engines were outside the warranty period. Some companies stepped up to the plate and offered special policies that helped owners address these factory installed shortcomings. However, many car manufacturers denied the issue and failed to assist owners with destroyed engines. Here’s my advice. I still recommend buying an engine with a metal timing chain. With that said, if this is a used automobile you need to research the most common engine problems for that model.
Problems with Rubber Engine Timing Belts
What do you think remains the most common engine problem on a vehicle that’s equipped with a rubber timing belt? That’s right, a stretched or broken timing belt. People love to ignore this part and when the belt breaks problems happen. Before we jump into the specific issues with these rubber components let’s ask the question why. How come the engine designers used a rubber belt to hold engine parts in time? Also consider how fast these parts spin and the heat the rubber becomes exposed to.
We all know that rubber degrades over time and stretches, but add these two conditions of heavy workload and high heat conditions and it’s a miracle this part lasts as long as the manufacturer states in the owner’s manual. This brings us to the average recommendations for replacing the timing belt. In the defense of the car companies using a timing belt, they have increased the quality of the factory installed parts. Now on some of these automobiles they don’t require service until they reach over one hundred thousand miles.
They didn’t really do this for customer satisfaction purposes. Instead, they did it because of the factory power train warranties that run 10 years 100,000 miles. What I’m saying is they didn’t want to replace the part or cover the damage if it broke under warranty. Car companies leave this for the vehicle owners. Which leads me to answer the first question, “why would they do this”? They are looking for you to return to the dealership. Maybe you pay top dollar for a timing belt replacement service or trade the car and instead. And if you don’t, you’ll run into the most common engine problem. That’s right, damage caused by the engine jumping time.