About

Most "is this engine reliable?" answers are one person's bad luck, or one dealer's sales pitch.

enginecreep exists to replace that with something closer to a pattern: what shows up again and again, across thousands of owners, official complaint databases, and repair forums — for the specific engine you're about to buy a car around.

Where the data comes from

Owner discussions pulled from relevant subreddits — what actually breaks, when, and how people fixed it.

Specialist forums

Marque- and model-specific forums (e.g. PistonHeads and others), searched for the engine code and its known failure terms.

NHTSA

Official US complaint and recall data — the same database regulators use, not a paraphrase of it.

HonestJohn Real MPG

Real-world fuel consumption reported by owners, compared against the manufacturer's official figures.

Wikipedia

Baseline specs — displacement, power, production years, chassis codes.

How raw data becomes one engine page

Two-pass collection

The first pass gathers everything findable for an engine. It is read once to pull out the specific terms people actually use for that engine's failures — a part name, a fault code, a nickname. A second pass searches specifically on those terms, so the data set goes deeper than a generic keyword search would.

Structuring, not summarizing

The raw data — Reddit threads, forum snippets, NHTSA complaints, recall text — is handed to an AI model with one rule above the rest: it does not invent or add issues that aren't present in the source material. Its job is to organize what's already there into a consistent shape, not to add expert opinion of its own.

Fixed format, every engine

Severity, repair cost ranges, km ranges, and the overall verdict all follow the same strict format across every engine, so a BMW N47 page and a Ford EcoBoost page are directly comparable, not written in whatever style happened to come out that day.

Sanity-checking the numbers

Reported fuel consumption is checked against what is physically plausible for that engine type — a naturally aspirated petrol four-cylinder and a turbo diesel six-cylinder do not have the same realistic range. If a figure falls outside what's plausible, or if "real" consumption comes out lower than the official rating (which would mean a more efficient engine in the real world than in a lab test — not how it works), it is marked as unavailable rather than shown as fact.

What this isn't

This isn't a guarantee, and it isn't a mechanic's inspection of the specific car you're looking at. It's a summary of what's publicly documented about an engine as a model — your exact example could have been maintained perfectly or neglected for years, and no amount of forum data can tell you which.

Owners who post online skew toward people having problems — nobody starts a thread to say their engine is fine. enginecreep tries to correct for that by cross-referencing against official complaint and recall data, not Reddit alone, but the underlying bias toward "things going wrong" is worth keeping in mind when you read a page.

Found something wrong on a page, or an engine that's missing entirely? That's expected at this stage — reach out and it'll get looked at.