When buying a used engine, warranty terms are often unclear. Some sellers mention "3 months", others "as is", and others a "remaining manufacturer warranty" whose real conditions nobody knows.
Yet the law is clear — and it protects you more than you might think. Here is what you need to know before you buy, so you are not left alone facing a breakdown.
The 3 types of warranty on a used engine
There are three distinct levels of protection that apply cumulatively:
Legal conformity guarantee
24 months mandatory
Applies whenever the seller is a professional. No contract required.
Hidden defects guarantee
2 years after discovery
Covers defects not visible at purchase. Also applies to private sales.
Commercial warranty
Variable by seller
Optional. Terms vary widely from one seller to another.
1 — The legal conformity guarantee (the most important)
Since January 1, 2022, the legal conformity guarantee has been extended to 24 months for any product sold by a professional — including spare parts such as used engines (Article L217-3 of the Consumer Code).
What this means in practice:
- The engine must be fit for its intended use and match the advertised specifications
- For the first 12 months, any defect is automatically presumed to have existed at the time of sale — the seller must prove otherwise
- After 12 months, you must prove the defect existed before sale — but the guarantee remains active for up to 24 months
- You may request repair, replacement or a refund depending on the case
What the legal guarantee covers on an engine
- Internal operating defects (compression, sealing, bearings)
- Non-compliance with the advertised engine code
- Defects present before sale but not visible on visual inspection
What the legal guarantee does not cover
- Normal wear parts (gaskets, timing belt, filters)
- Damage caused by incorrect installation
- Known defects disclosed at the time of sale
- Damage linked to poor maintenance after sale
2 — Hidden defects guarantee (Article 1641 of the Civil Code)
A hidden defect is a fault that:
- existed before the sale
- was not visible at purchase
- makes the engine unfit for use or significantly reduces its value
Unlike the conformity guarantee, the hidden defects guarantee also applies to sales between private individuals. You have 2 years from the discovery of the defect to take action.
Concrete example:
An engine has an internal crack on the block that is not visible to the naked eye and cannot be detected without dismantling. It causes gradual oil loss after fitting. That is a hidden defect — even if the seller was unaware of it.
3 — Commercial warranty: what sellers actually offer
The commercial warranty is optional — no law requires a professional to offer one on top of the legal guarantee. It is in addition, not a replacement.
In practice, here is what you find on the market:
| Seller type | Typical commercial warranty | Reliability |
|---|---|---|
| Private seller (classified ads, etc.) | None | |
| Salvage yard | 1 to 3 months (often exchange only) | |
| Non-specialist online reseller | 3 to 6 months (unclear terms) | |
| Specialist professional (e.g. Auketra) | 10 months, written terms |
Duration alone is not enough — what matters is what is covered, how to claim, and who is accountable.
5 questions to ask before buying a used engine
Before confirming a purchase, always ask:
-
How long is the commercial warranty and what exactly does it cover?
A serious seller must answer precisely — not just "3 months". -
Was the engine mechanically inspected before sale?
Compression test, oil analysis, bearing checks — see our inspected vs standard engine guide. -
Was the engine code verified and does it match your vehicle exactly?
Incompatibility can void warranty coverage. See our engine code guide. -
How do you claim the warranty if a problem occurs? What is the process?
Response time, labour for removal/refit, exchange or refund. -
Do you have written warranty terms?
A verbal warranty is worthless. Require a document attached to the invoice.
What Auketra offers: 10-month commercial warranty
At Auketra, every engine sold comes with a 10-month commercial warranty, in addition to your statutory rights.
This warranty covers:
- Internal mechanical defects found after fitting (compression, sealing, bearings)
- Non-compliance with the advertised engine code
- Technical support before and after delivery
It does not cover:
- Normal wear parts (gaskets, belts, filters)
- Damage from incorrect installation or poor maintenance
All our engines are inspected before shipping — it is precisely because they go through this process that we can offer this warranty. An uninspected engine cannot be seriously warranted.
Conclusion: warranty reflects the seller's confidence
A seller who offers a serious, written commercial warranty for a meaningful period is a seller who stands behind what they sell.
Conversely, a seller who offers no commercial warranty (beyond the legal minimum) or hides their terms sends a clear signal: they cannot commit to the condition of what they sell.
Warranty is not a marketing bonus. It is the simplest measure of the quality of the engine you are buying.
FAQ
10-month warranty, inspected before shipping
Every Auketra engine is inspected, tested and delivered with a 10-month commercial warranty — on top of your statutory rights.
