We are not a garage and we don't fit engines. What we do is vet the specialists who will — and here is the exact checklist we apply, including the things that disqualify a supplier outright.
We are an independent editorial resource, not a garage. We don't repair vehicles, we don't hold stock, and we don't fit engines. We research Mercedes engines, publish what we find, and route enquiries to a network of 15+ vetted specialists who do the actual work.
Full criteria, disqualifiers, our commercial model, and what happens when a specialist stops meeting the bar, below.
Every one of these is checked before a specialist receives a single enquiry from us.
| # | Criterion | What We Actually Check |
|---|---|---|
| 1 | Genuine Mercedes specialism | Demonstrable regular work on Mercedes powertrains — not a general garage that will accept the job |
| 2 | Minimum trading history | Established trading record, verifiable through Companies House and trading address |
| 3 | Written warranty on supply & fit | A stated, documented warranty period on both the unit and the labour — see our warranty standards |
| 4 | Engine provenance | Ability to state where a reconditioned or used unit came from and to what standard it was rebuilt |
| 5 | Response time | Consistent response to enquiries within a working day — slow responders are removed from routing |
| 6 | Complaint handling | A documented process for when a job goes wrong, and evidence of having used it |
| 7 | Insurance & premises | Current liability cover and a permanent, inspectable workshop address |
Any one of these removes a supplier from the network, regardless of how well they score elsewhere.
A verbal assurance is not a warranty. If it isn't documented, the specialist doesn't join.
Any supplier willing to quote a full engine replacement without seeing the vehicle or the diagnostic evidence.
If they can't say where a unit came from or to what standard it was rebuilt, we don't route to them.
Isolated problems happen in any trade. A pattern of them, or a refusal to engage with them, is disqualifying.
This site is free to use because specialists pay us for the enquiries we send them. You pay us nothing, and we take no commission on the work itself.
We'd rather explain that openly than let you assume the site runs on goodwill. And it's precisely why our editorial independence matters: if we only ever told people to replace their engine, we'd generate more enquiries in the short term and destroy the reason anyone trusts us in the long term. That's why our repair vs replace framework is published in full — including the 70% threshold above which we tell people not to replace — and why pages like is it worth replacing a C‑Class engine and when should you scrap a Mercedes exist at all. Our full position is set out in our editorial standards.
Vetting at the point of joining is the easy part. Specialists are reviewed continuously against response time, completion rate and post‑job outcomes collected through follow‑up surveys — the same data source behind our published case studies and our verified owner outcomes. Where a specialist's outcomes deteriorate, routing is reduced or stopped. Our data handling and tagging is documented on the data verification page, and any corrections we've had to make are logged publicly in our corrections log.
Removal isn't a single strike process. A specialist falling below the response‑time or completion‑rate bar first receives reduced routing rather than immediate removal, giving them a chance to correct course — most do. Full removal happens where a disqualifying issue is confirmed, such as an unresolved complaint pattern or a warranty dispute the specialist refused to engage with. We don't publish the names of removed specialists, both for straightforward legal reasons and because our purpose is steering future enquiries well, not running a public complaints board — but the removal itself is real and immediate once confirmed, and no specialist has ever been reinstated after a disqualifying removal.
We are not a garage, we are not a dealership, and we are not affiliated with Mercedes‑Benz AG. We don't hold engine stock, we don't carry out repairs, and we never present ourselves as the party doing the work. What we do is research — our annual failure index and published methodology are the clearest statement of that — and then connect owners with specialists who do. If you'd like to know more about the people behind the research, our expert panel page sets out who reviews what, and how it works walks through what happens after you make an enquiry.
Criteria, Not AdjectivesSeven specific checks, published — not a vague "trusted partner" badge.
Disqualifiers Published TooWe tell you what gets a supplier removed, not just what gets them in.
Commercial Model DisclosedSuppliers pay for enquiries. You pay nothing. Stated plainly.
Not a GarageWe research and route. We never claim to do the work.
Every enquiry routes only to specialists who meet the criteria on this page.
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