The car dies at a green light. You restart it, the person behind you leans on the horn, and you tell yourself it was a fluke. Three weeks later it happens again on a freeway on-ramp with your kid in the back seat.

That is the moment most people start looking for answers. Here is the one that matters: in California, an engine defect that keeps coming back after the dealer has had a fair shot at fixing it obligates the manufacturer to buy your vehicle back. Not offer you a goodwill discount. Not extend your warranty. Buy it back.

You also do not have to know what is wrong under the hood to win. That surprises almost everyone we talk to, and it is the single most important thing to understand about an engine defect claim.

Which Engine Defects Actually Qualify

California’s lemon law is the Song-Beverly Consumer Warranty Act. The operative section, Civil Code § 1793.2, says that when a manufacturer cannot repair a vehicle to match its written warranty after a reasonable number of attempts, it must replace the vehicle or refund what you paid.

The defect has to substantially impair the use, value, or safety of your vehicle. Engine problems clear that bar constantly:

• Stalling and no-starts. Losing power in traffic is a safety defect, and the law treats it that way.
• Misfires and rough running. Shaking at idle, hesitation under throttle, repeat ignition coil or injector replacements.
• Excessive oil consumption. If you are adding a quart between changes, that is a defect, not a maintenance habit.
• Oil and coolant leaks. A leak the dealer keeps chasing but never stops.
• Overheating. Head gasket, water pump, and thermostat repeats.
• Timing chain stretch, bearing failure, and engine knock. Often the warning before catastrophic engine failure.
• Limp mode and repeat check-engine lights for the same fault code family.
• Total engine failure or a replacement long block installed under warranty.

Software counts too. Modern engines are managed by control modules, and a reflash that quiets the symptom for a month before it returns is an attempted repair that did not work.

If your issue is not on this list, our overview of common car defects covered under California lemon law runs through the other systems that regularly qualify.

What You Prove, and What You Never Have To

An engine defect claim rests on three elements:

1. The defect substantially impairs the use, value, or safety of the vehicle. Value means value to you, not what a dealer’s appraisal sheet says.
2. You presented the vehicle to an authorized dealer for repair.
3. They failed to fix it after a reasonable number of attempts.

Notice what is absent. You never have to identify the failed component, name the root cause, or hire your own mechanic to diagnose it. California courts have been explicit about this: you prove the vehicle did not conform to the warranty, and that is the end of your burden. Proof that a problem was persistent and the dealer could not locate or repair it is enough.

That matters enormously with engine defects, because the manufacturer’s whole strategy depends on making the cause the argument.

How Many Repair Attempts Before a Buyback

California gives you a presumption, which is a legal shortcut that shifts the burden onto the manufacturer. Within the first 18 months or 18,000 miles, your vehicle is presumed to be a lemon if:

• It went in two or more times for a defect that could cause serious injury or death (stalling belongs here)
• It went in four or more times for the same non-safety defect
• It has been out of service 30 or more cumulative days for warranty repairs

Two clarifications. A visit where the technician road-tests the car and writes “could not duplicate” still counts. You presented the vehicle, the problem persisted, and the manufacturer had its chance. And missing the 18-month window does not kill your case. The presumption is a shortcut, not a ceiling, which is why lemon law claims can still work after your warranty expires when the engine defect first appeared while coverage was active.

Oregel v. American Isuzu: You Never Had to Ask

The case that put teeth in all of this is Oregel v. American Isuzu Motors, Inc. (2001) 90 Cal.App.4th 1094.

Marcelino Oregel leased a 1998 Isuzu Rodeo and had it serviced by the same dealer that leased it to him. The engine leaked oil. He brought it in six separate times and asked them to fix the leak. They never did. He started photographing the oil stains on his driveway. When he finally demanded a repurchase, Isuzu refused.

The jury found for Oregel and awarded $11,131.82 in damages, then added a civil penalty of the same amount for a willful violation. On appeal, Isuzu argued the leak was a maintenance problem and that it had never been given a real opportunity to repurchase. The Court of Appeal rejected both arguments and made two points that shape every engine defect case filed in California since.

First, the only affirmative step the law requires of you is giving the manufacturer a reasonable opportunity to repair the vehicle. Whether the dealer takes that opportunity seriously, or simply cannot isolate the problem, is not your responsibility. You do not have to write a demand letter to trigger the duty. The obligation to repurchase belongs to the manufacturer whether or not you ask.

Second, a manufacturer cannot escape a civil penalty by staying ignorant. Isuzu had never bothered to investigate the repair history before refusing. The court held that a decision reached without using information the manufacturer could easily have gathered is not a reasonable, good-faith decision. That is the reasoning that turns a stonewalled engine defect claim into a doubled award.

What a Lemon Law Buyback Actually Pays

Under § 1793.2(d), a qualifying vehicle entitles you to a comparable replacement or restitution. The choice is yours, not the manufacturer’s.

A lemon law buyback returns essentially everything you have put into the vehicle:

• Down payment and every monthly payment made to date
• Sales tax, license, and registration fees
• Finance charges you actually paid
• Incidental costs including towing, rental cars, and repairs you paid out of pocket

Only one deduction is permitted: a mileage offset for the use you got before the problem started. The formula is (miles at your first repair visit for that defect ÷ 120,000) × the price you paid. Miles you drive after that first visit cost you nothing, so the date your engine defect first showed up on a repair order is worth real money. Check which mileage figure the manufacturer used, because using your current odometer instead is a common and expensive error.

Then there is the Oregel piece. A willful refusal to honor the buyback can add a civil penalty of up to two times your actual damages.

After a Total Engine Failure

Complete engine failure changes the conversation but not the law. Manufacturers often replace the long block under warranty and treat the engine defect as resolved. It is not resolved. That replacement is a repair attempt, and if the same symptoms return, the earlier failed repairs still count toward your total.

Watch for two moves. The first is blaming maintenance, exactly what Isuzu tried. Keep every oil change receipt and that argument collapses. The second is blaming fuel, driving habits, or aftermarket parts you never installed.

Before your next service visit, run your VIN through NHTSA’s recall database. If your engine has an open recall or a technical service bulletin matching your symptom, the manufacturer already documented the defect. That is strong evidence and it is free to find.

Six Things to Do Starting This Week

1. Get a printed repair order at every visit, including “no problem found” visits, and confirm your complaint is written in your own words.
2. Note the exact date and mileage of your first engine-related visit. That number drives your offset.
3. Record video of the stall, the shake, or the smoke. Symptoms that vanish at the dealer are why claims stall.
4. Save receipts for oil changes and scheduled maintenance.
5. Save receipts for towing, rentals, rideshares, and any repair you paid for.
6. Do not trade the vehicle in while the claim is open.

Your Deadline Depends on Your Manufacturer

California’s process changed in 2025. Under AB 1755 and SB 26, automakers now choose between the traditional path and an opt-in track carrying a mandatory 30-day pre-suit notice, tighter filing deadlines, and required mediation. The Department of Consumer Affairs publishes the list of manufacturers who opted in each December, and our page on California lemon law laws and requirements covers what applies to your vehicle.

The short version: the windows got shorter. Waiting is the most expensive thing you can do with an engine defect claim.

Let’s Find Out What Your Case Is Worth

You paid for a vehicle you can merge onto a freeway in. If yours stalls, shakes, burns oil, or has already been apart once, you have a case worth taking seriously, and repair orders you have been collecting without realizing how valuable they are.

We take on the manufacturer, the deadlines, and the offset math. The manufacturer pays our fees, not you. Win or lose.

Bring us your repair history through our free case review or call (310) 525-2244, and we will tell you in one conversation whether your engine defect qualifies for a buyback.