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Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Honda’s clearest documented oil-dilution campaign involved certain 1.5L turbo direct-injection engines in 2016–2018 Civic and 2017–2018 CR-V vehicles. Honda linked excessive dilution particularly to repeated short trips in very cold weather. The campaigns were limited by model, year, market, and VIN, so an engine badge or model year alone cannot confirm whether a specific car was affected.
Which Honda engines and vehicles were involved?
The strongest manufacturer documentation concerns the 1.5L turbo direct-injection engine in certain Civics and CR-Vs. It does not establish that every Honda 1.5L turbo—or every Honda engine—has an oil-dilution problem.
| Market and vehicles | Documented scope | What to check |
|---|---|---|
| Canada: certain 2016–2018 Civic models with the 1.5L turbo direct-injection engine | Honda Canada described a campaign addressing excessive fuel and moisture dilution under particular conditions. Its December 2018 letter set out Canadian campaign terms. Honda Canada campaign letter | Confirm the vehicle’s VIN and campaign status with Honda Canada. |
| United States: certain 2016–2018 Civics and 2017–2018 CR-Vs with 1.5L turbo engines | Honda communications described product updates for eligible vehicles in 21 cold-weather states. Eligibility was VIN-specific. Honda U.S. campaign information | Ask an authorized Honda dealer to check the VIN and whether the applicable update was completed. |
The linked Honda campaign documents describe different market-specific scopes and procedures; do not apply Canadian warranty terms to a U.S. vehicle, or assume every vehicle in a listed model year qualifies.
What causes the oil dilution Honda described?
Some injected fuel can migrate past the cylinders into the oil pan. Repeated short trips in very low temperatures may leave the engine with less opportunity to warm fully; warming helps vaporize and burn off fuel that has entered the oil. Honda Canada noted that some oil dilution is normal for this engine, but that statement does not mean an unusually high oil level or warning symptom should be ignored. Honda Canada customer letter, December 2018
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What did Honda’s updates involve?
The remedy depended on market, vehicle, and bulletin version. Honda’s Canadian campaign letter described software changes to engine fuel-injection, CVT if equipped, and climate-control settings, plus an engine-oil replacement. It also described a six-year-from-first-registration warranty extension with no mileage limit for certain components and repairs associated with excess dilution before the update. Those terms are Canadian campaign terms, not a general warranty promise for vehicles elsewhere.
U.S. campaign materials described software updates and engine-oil replacement for eligible vehicles. A revised CR-V service bulletin directed dealers to check VIN status; a later procedure replaced an earlier A/C control-unit replacement step with a software reflash. For the CR-V campaign procedure, the oil filter did not need replacement. Follow the instructions applicable to the exact vehicle rather than treating any of these details as universal. Honda U.S. service bulletin
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These were product updates, not proof that every eligible vehicle developed the condition or that an update resolves every later oil-level or driveability complaint. Campaign completion and individual repair eligibility should be confirmed by VIN with Honda.
What symptoms did Honda identify?
Honda campaign communications listed possible symptoms, but none alone diagnoses oil dilution. The U.S. materials included lack of power and diagnostic trouble codes P0300–P0304 (misfires) and P0172 (rich fuel mixture). Honda Canada also listed check-engine indications associated with misfire or rich running, a low oil-pressure warning associated with moisture freezing in the oil pan, and, in exceptional cases, abnormal camshaft noise related to rocker-arm roller-bearing wear. A warning light or noise calls for diagnosis, not an assumption about the cause.
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- Delivers 20% better wear protection and 15% better sludge defense than industry standards to help prevent engine breakdown
- Extra detergents safeguard against friction, corrosion and deposits to keep high-mileage engines clean
- Advanced friction-fighting additives help maximize performance and improve fuel efficiency
- Provides performance benefits for high mileage, new and re-built engines alike
How to check a used Honda or your own vehicle
- Identify the model year, model, engine, and original market. The documented campaigns concern particular 1.5L turbo vehicles, not an engine designation by itself.
- Ask Honda or an authorized dealer to check the VIN for campaign eligibility and completion. A vehicle can match the model-year description without being covered.
- Request the service history, including documentation of any campaign update and oil replacement. If you have a symptom or an unusually high oil level, have the vehicle diagnosed even if a campaign was completed.
- Use the oil specification in the owner’s manual for the exact vehicle. The campaign sources do not establish one universal oil grade or an aftermarket oil as a fix.
Do not confuse dilution with an oil leak
Honda’s July 2025 bulletin for 2018–2026 Accord 1.5L turbo and 2018–2022 Accord 2.0L turbo models concerns an external oil leak at the timing-chain tensioner inspection cover, with insufficient sealant adhesion identified as a possible cause. It is not evidence that the Accord 2.0L turbo has oil dilution, nor does it expand the earlier Civic and CR-V dilution campaigns. Honda bulletin, July 2025
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How large was the U.S. campaign?
WardsAuto reported in 2019 that the bulletins covered about 143,000 2016–2018 Civics and 239,000 2017–2018 CR-Vs in 21 cold-weather states—nearly 400,000 vehicles expected to receive updates. These are historical reported campaign figures, not a count of vehicles still unrepaired today. Honda’s U.S. communications described the CR-V campaign announcement in October 2018, a scope expansion in December 2018, and a revised repair procedure in February 2019. WardsAuto, 2019
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- Advanced protection against the four main causes of engine breakdown: wear friction heat and deposits
- Delivers 40% stronger wear protection than industry standards to reduce friction and improve fuel economy
- Provides 15% better deposit defense vs. industry standards, keeping engines cleaner for smoother performance and longer-lasting protection
- Up to 2.5X better heat protection vs. industry standards to fight harmful sludge formation and thermal breakdown
- Engineered for excellent low-temperature flow, reducing metal-to-metal contact during cold starts — when most engine wear typically occurs
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