Toyota Camry 2.5L Fuel Dilution: 2018–2022 Owner’s Guide

Pull the dipstick on a short-trip-driven 2018–2022 Toyota Camry 2.5L and the reading doesn’t add up at first glance. Oil is supposed to go down between changes, not up. Yet on cars built around the A25A engine, lab-analyzed samples have come back showing more than 5% gasoline by volume in the sump — about the point where 0W-20 oil loses a quarter of its viscosity. That’s the detail that makes an owner look twice: the level creeps up the dipstick instead of dropping, and it starts to carry a whiff of raw fuel. Ignore it long enough and the diluted oil lubricates poorly, capable of triggering a low oil pressure warning in extreme cold — but the ending is avoidable, and it comes down to a few cheap habits.

Which Camrys — and engines — this affects

Before following the symptom any further, it helps to know which engine is actually under the hood. The pattern centres on the A25A-FKS (the 203-hp gasoline 2.5L) and the A25A-FXS (the Atkinson-cycle hybrid version), fitted to Camrys sold in Canada from 2018 through 2022. Both share their core architecture with the M20A in the Corolla, and Toyota’s guidance treats the two the same way. If the car in question carries the 3.5L V6 instead, none of this applies — that’s a different engine entirely.

The symptom that surprises owners: a rising oil level

Most oil-related detective work starts with a level that’s falling — the question is only how fast. This one runs backwards. Fuel slips past the piston rings and lands in the sump, so the level climbs toward, and sometimes past, the full mark. The clue isn’t unique to the Camry, either: a widely read owner report on the same A25A-FXS engine in a 2019 RAV4 Hybrid describes an identical pattern — a dipstick that kept reading higher after every change, backed up by lab testing at over 5% fuel dilution.

The signs worth watching for, roughly in the order a tech would notice them:

• Oil level at or above the full mark, or higher than at the last change
• A sharp gasoline smell on the dipstick or filler cap
• Milky, tan, or foamy oil (usually extreme cold — that’s moisture, not just fuel)
• A low engine oil pressure message on the dash
• A check-engine light with codes P05202A or P052477

Why it happens, in plain terms

Follow the fuel and the mechanism isn’t mysterious — it’s three ordinary things stacking up at once. Modern direct-injection engines deliberately run rich on a cold start, spraying in extra fuel before the cylinder walls are warm enough to burn all of it cleanly. Some of that fuel condenses on the cold metal instead, and gravity does the rest — it washes down past the piston rings and joins the oil below. Oil is built to shed that gasoline, but only by reaching full operating temperature and holding it there long enough to boil the contaminants back out. A five-minute commute never gets it there.

The hybrid drivetrain makes the problem worse, not better. The A25A-FXS shuts its engine off constantly in stop-and-go traffic, so a cold “trip” often means the engine spends more of it off, or running cold and rich, than actually warmed through. Add a Canadian January to that mix, and moisture from blow-by gases can freeze inside the oil — exactly the chain of events Toyota lays out in its own service bulletin.

When it becomes a safety issue

Here is where the diagnosis stops being academic. Diluted oil is thinner oil, and around 5–6% fuel content, 0W-20 can lose roughly a quarter of its viscosity — wear protection drops right along with it. In ordinary cold that’s a slow, watchable problem. In extreme cold it turns urgent: Toyota’s bulletin warns that accumulated moisture can freeze and drop oil pressure low enough to light warnings and set fault codes. That’s the point where the smart move is to stop driving — sustained low oil pressure is exactly how bearing damage gets started. Short of that, this is wear you monitor and manage, not a failure that happens overnight.

What Toyota has said — and the class-action backdrop

Toyota has already opened this file. Its official answer is TSB T-SB-0104-21 (December 2021), covering 2018–2022 vehicles built with the A25A-FKS, A25A-FXS or M20A-FKS. It names the same evidence a tech would gather — milky or discoloured oil, the low oil pressure warning, and codes P05202A/P052477 — and attributes all of it to moisture from blow-by condensing during short trips in extreme cold. The bulletin then walks dealers through an inspection and repair procedure. Naming the TSB number at the service desk tends to move the conversation along faster.

Widen the lens, though, and there’s context worth knowing. As of this writing, there is no Transport Canada safety recall and no certified class action specific to A25A fuel dilution — the remedy path runs through the TSB, plus warranty or goodwill, not a mandated fix. Toyota’s history with oil-related class actions isn’t clean, though: it has settled a sludge case covering roughly 3.5 million vehicles, and a 2AZ-FE oil-consumption case that ended in extended warranty coverage and reimbursement. That history is exactly why experienced Toyota owners keep such close watch on a newer engine family’s oil behaviour — and why a dated dipstick photo and a stack of service invoices are worth holding onto. Running the VIN against official records is the natural first move (see how vehicle recalls work in Canada).

What it costs in Canada

Catch the dilution early and the fix reads like ordinary maintenance, not repair:

• Full-synthetic oil change (the A25A takes about 4.5 L of 0W-20 with a filter): typically $80–$120 CAD, per Driving.ca’s national survey — averages land near $100.
• Lab oil analysis (the test that turns a suspicion into a number, mailed in with your change): typically $40–$80 CAD — worth doing once a winter if most trips are short.
• Dealer TSB inspection and oil service: roughly $120–$250 CAD depending on the dealer.
• The ending if the story gets ignored — bearing wear leading to engine replacement: a used low-kilometre A25A installed typically runs $4,000–$8,000 CAD. That gap is the entire reason the $100 oil change exists.

Six habits that keep dilution in check

Once the mechanism is understood, breaking the cycle is mostly habit, not heroics:

1. Check the dipstick monthly, under the same conditions each time — a rising level tells you everything you need to know.
2. Shorten the interval. Mostly trips under 10 km? Change at 6 months or 8,000 km instead of waiting for the maintenance minder. Our synthetic vs. conventional oil intervals guide covers the severe-service logic behind that math.
3. Give it one long run a week. Twenty to thirty minutes of steady highway driving is enough heat, held long enough, to boil the fuel and moisture back out of the oil.
4. Skip the idle warm-up. Extended idling only piles on more rich-running time with no load to burn it off; gentle driving from the first minute warms the oil faster.
5. Get one oil analysis. A single lab report replaces guessing with an actual dilution percentage — the difference between a hunch and a diagnosis. And resist the urge to top up with a heavier oil to compensate; use the correct 0W-20, changed on schedule (see our motor oil buying guide for Canada).
6. Keep records. Dated photos and invoices are the evidence that protects you if Toyota extends coverage later.

Honda’s 1.5T engine tells a strikingly similar short-trip story — our Honda Civic oil dilution guide walks through that parallel case.

Buying a used 2018–2022 Camry? Do this in the lot

Standing in front of a used Camry, the same diagnostic instincts apply — just compressed into a few minutes in a parking lot:

• Pull the dipstick cold. A gasoline smell, a level above full, or milky residue at the cap answers the question before the hood’s even fully up — negotiate hard or walk.
• Ask for oil change records. Frequent, dated changes are the best sign this engine has been looked after; no records from a short-trip seller means budgeting an immediate change and analysis.
• Cold-start it and watch the dash. Any low oil pressure message, or a check-engine light that lingers, needs a code scan before any price talk continues.
• Scan for P0520-series codes with a basic OBD reader — cheap, and it settles the question fast.
• Run the VIN through Transport Canada’s recall database to catch any open campaigns, and ask what TSB work has already been done.

On this generation, those few checks are what separate a well-kept engine from one that’s been quietly diluting itself for years.

Frequently asked questions

Is fuel dilution common on the 2018–2022 Toyota Camry? It’s less a guaranteed defect than a pattern that keeps showing up under the same conditions. Owner reports cluster around Camrys — hybrids especially — driven on repeated short trips in cold weather. Toyota’s own TSB T-SB-0104-21 covers A25A-equipped 2018–2022 models for exactly this kind of oil contamination from short-trip driving, which is the manufacturer’s own confirmation that the pattern is real.

Why is my Camry’s oil level rising on the dipstick? A rising level is the oil telling you that fuel and moisture are arriving faster than they can evaporate back out. On the Camry’s A25A 2.5L, repeated cold starts paired with short trips let gasoline wash past the piston rings and settle into the sump. Owners of the same engine family have sent samples to a lab and measured over 5% fuel in the oil — reason enough to check the level monthly and shorten your interval if most of your driving is short hops.

What does Toyota’s TSB T-SB-0104-21 actually cover? The bulletin covers 2018–2022 Toyotas with the A25A-FKS, A25A-FXS or M20A-FKS engines showing milky or discoloured oil, a low oil pressure warning, or fault codes P05202A/P052477. Toyota’s own explanation points to moisture from blow-by condensing in the oil during short trips in extreme cold, and the bulletin walks dealers through an inspection and repair procedure to confirm and address it.

How often should I change oil if I only drive short trips? Cut the normal interval in half. If the maintenance minder would otherwise wait for 12 months or 16,000 km, a short-trip Camry is better served changing at 6 months or 8,000 km, with one 30-minute highway run worked in each week. In Canada, a full-synthetic oil change typically runs $80–$120 — a small price against oil that’s already lost its viscosity to fuel.

Is there a recall or class action for Camry fuel dilution? Not as of this writing — no safety recall and no certified class action specific to A25A fuel dilution exist yet. Toyota’s answer so far is TSB T-SB-0104-21. The company does have a track record of settling oil-related class actions on other engines (the sludge case, and the 2AZ-FE oil-consumption case), which is exactly why owners tracking this issue are keeping records and checking for updates.

Sources & further reading

• CarComplaints.com — Toyota TSB T-SB-0104-21 text (2018–2022 A25A/M20A engines)
• RAV4World forum — “Anyone having fuel dilution issues?” (A25A-FXS owner oil analysis, >5% dilution)
• Bob Is The Oil Guy — Toyota/Lexus A25A-FXS hybrid engine oil discussion (dilution vs. viscosity)
• Driving.ca — How much does an oil change cost in Canada?
• Center for Auto Safety — Toyota oil sludge class-action settlement coverage
• Paul’s Travel Pictures — 2018–2022 Camry 2.5L A25A-FKS oil change guide