The 2.0-liter DOHC F20C inline-four uses aluminum construction for the block, cylinder head, and oil pan, and makes use of Honda's proprietary V-TEC system to vary valve timing and lift. It is widely considered to be the best powertrain that Honda has ever developed but that doesn't mean it is completely without its faults. The main issue with this engine in particular is excessive consumption of oil. Owners have noted that the sports car can consume up to a quart of oil every 1,000 miles. If it lands up using more than this, there may be a serious issue at hand. S2000 owners must check the oil level regularly, as these engines are known to all burn some oil. Allowing the oil level to drop too low can cause many reliability problems.
If a higher consumption is being experienced, you may start noticing a strong burning oil smell, lower than usual engine oil levels, or a smoking exhaust. If this is the case, there could be a leak from the piston rings and valve seals. This is usually the case for high-mileage cars. Extremely durable fiber-reinforced metal (FRM) is used for the cylinder liners but apparently, the rings wear out relatively quickly. A properly maintained engine's cylinder liners should therefore be good for years and the rings are often the only things you have to replace to restore proper compression and power to an oil-burning F20C. A clogged PCV valve has also been noted to be a common culprit for high oil consumption in the S2000. Valve-stem seals can also deteriorate in high-mileage cars which is a costly job to repair as it requires the powertrain to be opened up. It is also recommended that you switch to an oil with a higher viscosity to lower the oil burn-off.
Another one of the notable 2000-2003 Honda S2000 engine problems on the F20C, in particular, is cracked valve-spring retainers. This is caused when one of the pistons makes contact with a floating valve which may be a common occurrence in this powertrain as it can rev at a high engine speed. You may have this issue if you notice a loss of power or misfiring at high rpms. Starting and idling should be unchanged, but you'll notice inconsistencies once you pass the 4,000 rpm mark. This is because the valves will not have the integrity to maintain the engine speed. If you detect this issue, it's recommended that you deal with this issue immediately as it can cause catastrophic damage to the powertrain. The valve may detach from the housing and drop into the cylinder, which will result in terminal engine damage. To see if a cracked valve spring is the issue, it is best to conduct a vacuum test which can be done by connecting a vacuum gauge to the vacuum port of the intake manifold. Idle the engine at 4,000 rpm and take note of whether the vacuum readings oscillate as the engine speed increases. If you don't have access to this equipment, you may have to remove the valve cover and cams and inspect the valves for damages. If the retainer is cracked, the part will need to be replaced. It is advised that you replace all retainers rather than just the affected part to maintain a consistent spring pressure.
Honda's timing chains are known to be fairly robust, but in the F20C mill, they can give in at the 105,000-mile mark, especially in case of lax lubrication maintenance. If this occurs, the damage to the engine can be severe. You'll know that your chain is on its way out when you notice a ticking noise from the tappet while idling, regardless of temperature. If left for too long, the chain will deteriorate and result in a loss of power and misfiring. A timing chain for the K20C will cost $178 together with a $309 tensioner. The labor may set you back by another $650. If you replace the engine oil frequently, the timing chain should be reliable, but the tensioner can fail from around 100,000 miles anyway and should be replaced at this mileage or sooner with an updated Honda-supplied part if this has not been done already. Engine rattling may be either a tired chain or, in well-maintained engines, more likely a tired tensioner. Replace it without delay, as this is a high-revving engine that places high demands on its valve gear.
The very similar 2.2-liter variant of the engine is at risk of suffering from some of these issues as well but with the subtle updates that Honda applied to this powertrain, it is less likely. In fact, there are significantly fewer F22C1 2004-2009 S2000 engine problems. For example, the cracked valve retainers don't seem to be an F22C1 problem at all. A word of warning though: some owners modify these cars, so to ensure reliability, make sure it is completely stock. The rev limit cannot be safely increased without modified pistons and con-rods and the F22C1 can not be made to rev as high as the F20C without developing problems. While this list of problems may seem long, the engine is inherently very reliable as long as it is meticulously maintained and the common trouble spots are monitored. We cannot stress enough how important it is to keep the oil topped up between services.
Mileage: The issue of higher oil consumption and cracked valve retainers s likely to appear after the 150,000-mile mark. The chain tensioner should be replaced every 100,000 miles at the latest. Hard-driven Honda S2000 models that have not had frequent oil changes may suffer from a failing timing chain at 105,000-miles.
Cost: A set of piston rings for the F20C engine will cost $108 while valve seals will set you back $3 per seal. One valve spring retainer costs $6. The parts are relatively inexpensive but the labor is intensive with both jobs costing anywhere from $1,000 to $1,200. The timing chain and tensioner will cost $487 excluding a labor cost of $650.
How to spot: If your S2000 starts consuming a high level of oil or you notice a burning oil smell, this could be an indication that the piston rings or valve seals are on their way out. Misfiring in the higher rpm range may signify that your valve spring retainers are worn out. Rattling or tapping sounds, or if the engine suffers from a loss of power or misfiring, usually indicate a tired timing chain or chain tensioner.