Common K20 problems and issues

"Find out what the common K20 faults are"

The K20 is a very reliable engine, however, like most engines, there are some common weak spots, issues, and problems so we've put them all here in this handy reference guide to help you track down these issues and hopefully avoid problems.

In general, K20 engines are dependable and sturdy machines, as long as you adhere to the manufacturer's service schedules and use high-quality oil to guarantee long-term performance. Providing they are serviced and maintained on a regular basis, there should be few concerns.

Regular oil changes are essential for the K20, particularly when the engine is tuned, and will assist to prolong the engine's life and dependability. When the improper grade of oil is used, the camshaft is frequently the first component to experience issues.

If you are wanting more power please check out our K20 tuning guide.

Make sure the valves are adjusted and replace the timing chain before the manual suggests, we feel 120,000 miles is too long but it depends greatly on how the engine is treated and what sort of operating range it is used in.

Check out our video introduction to Common Honda K20 Problems, all you need to know and full guide.

K20 problem areas to keep an eye on.

Here are the issues we will cover on this page. What are the most common K20 problems and issues?

  • Following tuning modifications, K20 has been experiencing problems.
  • Troubleshooting difficulties with the K20 crankshaft oil seal
  • Troubleshooting the K20  knocking sound
  • Rough idle issues with the K20
  • Vibration issues
  • Carbon build-up problems
  • Following tuning modifications, K20 has been experiencing troubles in some cases.
  • Exhaust Cam Lobe Pitting

Problems after K20 Tuning

While some of our members have reported issues with flat spots or glitches following the application of mods and upgrades or tuning, this is not usually related to the engine's design; and is most commonly down to airflow or fuelling issues.

Please see our article on diagnosing flat spots and problems after tuning, which should assist you in getting to the bottom of the problem - diagnosing flat spots and problems after tuning

Troubleshooting difficulties with the K20 crankshaft oil seal

Another problem that occurs often with these engines is oil leaking from the front seal of the crankshaft.

An examination of your K20's front crankshaft oil seal should indicate if it is prone to weeping small amounts of oil while the engine is running. This is a minor annoyance but can create a burning oil smell in the car, leave oil deposits on your drive and necessitate more frequent oil top-ups.

This issue may be resolved by replacing the seal (never use oil treatments to "fix leaking seals").

Troubleshooting the K20 banging  knocking sound

Several K20 owners have reported hearing knocking noises in their cars. The best-case scenario is that changing the valves or just checking the clearances will resolve the issue.

It has been noted that low octane fuel can sometimes cause a knock or pinking sound, but this usually goes away after higher octane fuel is used.

Although it is possible for things to go worse, the exhaust camshaft may eventually get worn out and must be replaced after a period of time. The constant wear degrades the lobe and reduces the lift of the camshaft so you have worse performance and an annoying knocking sound.

The wear will accelerate over time if it is not addressed and starts quite slowly so investigate these knocking sounds at your earliest convenience.

There are many instances of engine mount failure, and you will notice increased engine vibrations when this occurs, but this is not a reason for alarm just a minor annoyance.

Rough idle issues with the K20.

A broken idle control valve may also result in a harsh idle. It is worth periodically cleaning the throttle body and while you are at it make sure the air flow meter is clean and in good order.

The throttle body gets dirty and may also need to be cleaned if the engine is idling poorly and is probably the single most common cause of rough idling on the K20.

Vibration problems and issues in the K20

The engine mounts are the typical cause for vibration problems as these are made from rubber and degrade over time.

These vibrations have a nasty habit of causing other issues so it's best to get this sorted sooner rather than later.

Occasionally the timing chain can cause issues when it stretches you'll notice rattling and poor running with flat spots when this happens.

K20 Carbon build up problems

Carbon accumulation in the head, on the other hand, might result in flat areas in the power band, which can impair the vehicle's overall performance. This tends to happen on very high mileage engines, and is nowhere near as bad as direct injection motors.

Even though this is a more serious problem with direct injection engines, it should be kept an eye out for on all engines, particularly as the mileage increases. How to get rid of carbon build up is covered in detail here removing carbon build up..

Fouled spark plugs can cause misfiring and flat spots, so using good quality fuel and occasionally putting in a fuel cleaning additive will help improve matters and reduce the need for Maintainance.

Exhaust Cam Lobe Pitting

This issue has been mentioned a couple of times by commenters and forum users, so after a little digging around it does seem to affect quite a few of these engines around 2003 to 2011.

You'll notice this issue as lifter noise or chatter.

Wrong oil selection can cause this problem to happen more quickly. It is strange this does not affect the intake cam, just the exhaust ca, but it does seem to be a regularly reported issue on the K20 and K24 engine.

There is much debate over the cause of this pitting and galling on the cam lobes but many seem to feel it is down to the casting methods used to make these cams.

Please provide us with your thoughts in the comments section below to help us improve these suggestions.

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Please consider joining us in our forums if you would want to exchange ideas and information with other K20 owners. We have a specialized Honda tuning area as well as general vehicle forums, and we don't have the off-topic banter and hostility that can be found on so many auto sites these days.

So do join us in our welcome forum, where you can discuss K20 tuning alternatives in more depth with other K20 owners who are also interested. We recommend that you read our impartial Honda tuning articles as well so that you can understand the advantages and disadvantages of each adjustment.

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