Honda Accord Engine Problems

The question of a Honda Accord timing belt or chain is not exactly a simple one to answer as there have been various permutations of the Accord theme sold in Australia over the years. In fact, even though they all bore Accord badges, the various Accord models have often been quite different from each other, including some very different models that sold alongside each other at the same time. So here’s how it pans out:

Very early Honda Accords sold here used toothed rubber timing belts, but those cars from 1977 through to the mid-90s are now pretty old, hard to find and don’t really make it to most people’s short-lists when shopping for a new second-hand car.

Fast forward to 1997, and we start to get into cars that might still have some broad appeal as second-hand buys. Of those, the 1997 to 2003 Accord used two engines, a 2.3-litre four-cylinder and a 3.0-litre V6. Both those engines used a toothed, rubber timing belt which needs to be changed at 100,000km intervals.

For 2003 to 2007 Accords, the engine choices remained a four-cylinder and a V6, but now the former was from Honda’s K Series of engines and featured a timing chain rather than a rubber belt. The V6 remained the same as the previous model. For 2008 to 2013 Accords, the news was similar with the four-cylinder carried over (with its timing chain) and the V6 enlarged to 3.5 litres but still from the same family of engines (and still with its rubber timing belt). In fact, that was to remain a theme for the whole of Accord production with the smaller engine using a timing chain and the V6 getting a rubber belt. Even the very last Accord, the current-model, uses a turbocharged four-cylinder engine with a timing chain, while the hybrid Accord uses an unconventional petrol engine, also with a timing chain.

If, however, we’re talking about the Accord Euro which was sold here right alongside the Accord between 2003 and 2015, the question is a bit simpler as only one engine was offered in that car; a 2.4-litre four-cylinder which used a timing chain (it was also from Honda’s K Series family).

Beyond that, the task of the timing chain or timing belt is exactly the same: They take drive from the engine’s crankshaft to the camshaft and, in the process, keep all the moving parts in harmony. Many car makers moved away from a timing chain to the rubber, toothed drive belt as a way of simplifying engine design and driving down the cost of each engine. The rubber timing belt is also quieter in its operation and is also less prone to stretching (as a timing chain can) so the camshaft (commonly referred to as the cam) stays in perfect synch with the rest of the engine’s rotating parts. The timing belt is a simpler design because it doesn’t need to be tensioned via oil pressure from the engine as many timing chain systems are.

The timing chain, meanwhile, is preferred by some manufacturers because it should last the lifetime of the engine and never need replacement. This isn’t always the case, however, and some engines designs from a variety of manufacturers suffer problems in this regard. But, in a properly maintained engine of sound design, the timing chain should never need attention, while the rubber timing belt generally requires periodic replacement.

I have never heard of ants invading an ECU before, it's not something we have heard about here at Carsguide. I find it hard to believe that ants could, in fact, get into an ECU that is located in a position that isn't exposed to the elements, including ants. I would have thought Honda might have been interested in at least checking your car to see how the problem occurred.

Unfortunately it would appear you are dealing with an incompetent or deceptive dealer. Ask to see proof of what work has been done by the dealer, and have them justify their findings to you. I would also take the case to Honda direct and demand head office intervention. Also consider taking your case to consumer affairs.

Honda claimed an overall average of 9.2 L/100 km, but that's derived from a lab test and not real life. Even so it should be an indication of what you could expect, and that seems to be mirrored by your real life results. It would seem that it's probably running rich and your theory of a faulty CO2 sensor could be on the money. Your dealer should be able to check it and confirm if it's a problem or not.

Most engines are optimized to run on one fuel or another, and that's the fuel they run best on and deliver the best fuel economy, but they also have 'knock' sensors that detect pre-ignition and adjust the ignition timing to avoid it. That means that while they have been optimized to run on one fuel they can also run on another, lower quality one. Generally your car will run better on premium unleaded than they will on regular unleaded. But we were let in on a little secret and that is that the regular unleaded we are buying is no different to the premium on sale. It seems it's more economical for oil companies to produce one type of fuel instead of two. What they do is guarantee the minimum octane rating of the fuel they produce, in the case of regular unleaded that's 91 whereas premium is a minimum of 95, they don't talk about the maximum octane rating. In that case we are wasting our money buying premium when regular is the same fuel. That was last week, what they will do next week is anybody's guess. Why do we pay more for premium? Simple, clever marketing by the oil companies that has convinced us it's better.

THE Accord is designed to run on regular unleaded and you won't have any problems with it if you do, but there are advantages with PULP. The engine's management computer needs time to adjust its settings to the new fuel so it may take a couple of fills to see any change. I wouldn't bother running it on PULP.