Introduction to the K-Series Honda Engine

By Hatsukari715 - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3125381

If you own a non-SUV Honda or Acura made after 2001, chances are there is a K-Series engine under the hood. The Honda K-Series is one of the most prolifically produced engines in the world. Used in millions of cars with tens of different variations, the K-Series is adaptable if nothing else. These engines are truly the jack of all trades, good fuel economy, good power, good torque, reliable, efficient, whats not to like?

The K-Series has seen many, many iterations over its long use period. We will not be going into each variation of this engine, there's just too many to cover. Instead, we will go over the information any K-Series owner should know in basic, digestible terms.

Common Problems

The K-Series is generally a very reliable engine, but like anything else, they are not without their flaws.

• Oil Consumption: Some years of the K-Series have problems with the piston rings wearing down and allowing too much oil to slip by into the combustion chamber. This causes excessive engine oil to be burned in the cylinder, leading to a progressive loss of oil, poor emissions, and potentially engine failure. The main cause of this problem is infrequent oil changes. K-Series owners are advised to change their engine oil every 5,000 miles and use only synthetic engine oil and Honda OEM oil filters.

• Variable Valve Timing Actuators: The variable valve timing (VVT) is an ingenious system that allows the engine to modulate the lift and duration of the intake and exhaust valves. Doing so allows the engine to produce more power during aggressive driving, and improved fuel economy during cruising. The VVT system uses a pair of actuators attached to the end of the camshafts to make these adjustments in real time. Sometimes, these actuators can fail prematurely. When they fail, often times you will hear a rattling noise from the engine right after it starts up and the noise quickly goes away within 3 - 10 seconds. Unfortunately, a failure with the VVT actuators can quickly lead to more expensive and invasive repairs such as a failed timing chain. Much like the oil consumption issue, the main cause of premature VVT actuator failure is infrequent oil changes. As stated previously, K-Series owners are advised to change their engine oil every 5,000 miles and use only synthetic oil with OEM Honda oil filters.

• Oil Leaks: The K-Series is not an engine known for leaking oil, but there are a few places we have noticed leak more often than others. Particularly, the VTEC spool valve, timing chain cover, timing chain inspection cover, oil filter adapter, and valve cover seem to be the weak spots on these motors. Thankfully, all of these are easy fixes!

Maintenance Requirements and Intervals

The K-Series (and Honda engines in general) have some special maintenance requirements that many other vehicles do not. This is because of Honda's unique design.

• Oil Change: The number one thing you can do to prolong the life of any engine, but especially the K-Series, is consistent and on-time oil changes. Change the oil no later than every 5,000 miles. At 5,001 miles, you are late.

• Air Filters: Some people will tell you air filters need to be changed every 30, 20, or even 10 thousand miles. This is mostly malarkey, as it all depends on how and where you drive your car. I recommend having your air filter checked with every oil change and replaced when it is dirty enough to impede air flow to the engine.

• Spark Plugs: Honda uses Iridium spark plugs. Iridium is a special metallic element that holds up extremely well at high temperatures, and is highly electrically conductive. Iridium spark plugs are a bit pricey, but easily last 100,000 miles when properly installed. Honda recommends replacing your spark plugs with OEM approved Iridium spark plugs every 100,000 miles.

• Valve Clearance Adjustment: Honda does not use hydraulic valve lifters (for good reason, in my opinion). As a result, K-Series engines need to have their valve clearance adjusted every 100,000 miles. Valve clearance is the distance between the rocker arm and the top of the valve. Improper valve clearance can cause premature wear of engine components, poor performance, poor fuel economy, and failed emissions.

Overall, the K-Series is a robust and good-performing engine platform for many uses. Honda seems to agree, as the K-Series continues to be produced in everything from the Civic Type-R to the base model Accord.