Getting your own mechanic to look at it
The single highest-value hour in the whole process, and the one most people skip because they are not sure how to ask. Part one is the procedure. Part two is the sheet to hand the shop.
A pre-purchase inspection is not a mechanic telling you whether to buy a car. It is a mechanic telling you what the car is, in writing, so that you can decide with the same information the seller has. That distinction is worth holding on to, because it changes what you ask for and what you do with the answer.
Part one — the procedure
Pick the shop first
Find your independent shop before you find your car, because the week you find a car is the week you have no patience for phone calls. Look for a shop with no relationship to the seller — not the seller's recommendation, not the place next door to the lot. A shop that regularly works on the brand is better than a generalist, and a shop willing to talk to you on the phone before you commit is better than either.
Ask four questions
Do you do pre-purchase inspections? Does it go on a lift? How long do you need the car? And what does it cost? The cost varies by shop and region — we are not going to quote a figure that would be wrong somewhere — but the useful frame is that it is a small fraction of any single repair it might find. Book it before you need it if you can.
Raise it with the seller early
Ask on the phone, before you drive out: I'd want my own mechanic to look at it — is that all right? Asked early it is procedural. Asked at the end, standing next to the car, it sounds like an accusation and gets a worse answer. A yes with conditions is still a yes. A flat no, or an insistence on their shop, is the most useful thing you will learn that day.
Solve the logistics in advance
Somebody has to get the car to the shop. With a private seller that usually means they drive it and you follow, or you go together. With a dealer it is often simpler than people expect — most straight dealers will release a car for an inspection with a copy of your license, and a small lot will frequently just hand you the keys. If the car genuinely cannot be moved, mobile inspection services exist, though they cannot replicate a lift.
Send the shop the details
Year, model, engine, mileage and the VIN, plus the three specific things you noticed on the test drive. A technician who knows you heard something over bumps at low speed will go looking for it. A technician handed an anonymous car will run their standard list and may never drive it over the bump that matters.
Be there, and stay out of the way
Being present is worth doing — you will see the car on a lift, which almost no buyer ever does, and a technician pointing at something is worth three paragraphs of report. Standing under the car asking questions while they work is worth nothing to anyone. Ask at the end.
Get it in writing, with costs
A verbal "it's pretty good" is not a document and cannot be used. Ask for the findings written down and, critically, for estimated cost per item. A list of faults is a worry. A list of faults with prices is a negotiating position and a budget.
Use it in one of three ways
Walk away, if the findings are structural, safety-related or simply more than you want to own. Go back with the itemized estimate and ask for the price to reflect it — an estimate from a third party is a far stronger argument than an opinion. Or buy it as-is knowing exactly what is coming, which is a perfectly good outcome and the most common one.
Part two — the request sheet
Hand this over, or send it the night before. Most of it is what a good shop would do anyway; writing it down means the report comes back in the form you can actually use.
Pre-purchase inspection — requested checks
Please note findings and an estimated cost for each item, not just pass or fail.
- Structure and corrosion
- Full underbody on a liftFrame rails, subframes, mounting points and floor pans, with anything bent, welded, kinked or replaced noted.
- Corrosion assessmentRockers, wheel arches, suspension mounting points, brake lines and fuel lines. Note whether any undercoating looks recently applied.
- Evidence of prior repairOverspray, mismatched panel finish, non-factory fasteners, replaced or re-stamped panels, aftermarket glass, paint on rubber seals.
- Mechanical
- Fluid leaks, by sourceEngine, transmission, differential, transfer case, power steering, brake and coolant — identified individually rather than as "some seepage".
- Engine oil condition and levelIncluding any sign of coolant intrusion or unusual deposits.
- Cooling systemCoolant condition and freeze protection, a pressure test, and confirmation that the cooling fans cycle.
- TransmissionFluid condition where it is checkable on this vehicle, plus shift quality noted on the road test.
- Belts, hoses and CV bootsCondition, cracking, and any boot that is split or weeping.
- Exhaust systemEnd to end, including hangers, heat shields and any leak at the manifold.
- Wear items, measured
- Brakes with measurementsPad thickness and rotor condition at each corner as numbers, not as "ok". Note if pads were replaced on worn rotors.
- Tires, corner by cornerTread depth at each, the four-digit date code on each, and any wear pattern suggesting alignment or suspension trouble.
- Suspension and steeringBushings, ball joints, tie rods, wheel bearings, struts and shocks, with any play quantified.
- Electrical and electronic
- Battery and charging system testWith the printed result if the tester produces one.
- Full diagnostic scanAll modules, not just the engine — including stored codes, pending codes and freeze frame data.
- Readiness monitorsPlease confirm whether emissions monitors are set. Monitors that have not completed can indicate a fault code cleared very recently.
- Air conditioningIf ambient temperature allows it to be tested. If it does not, please say so rather than leaving it blank.
- Judgment
- Road test impressionsAnything you notice that is not on this list, in your own words.
- The two questionsWhat would you fix first, and roughly what would it cost? And is there anything here that would make you walk away?
What an inspection is not
It is a snapshot taken on one morning by one person with a lift and a scan tool. It cannot see inside a sealed transmission, it cannot predict when a water pump will decide it has had enough, and it is not a warranty. Cars that pass a thorough inspection still break, and that is not a failure of the inspection.
What it reliably does is eliminate the expensive surprises — structural damage, serious corrosion, a fault that was cleared last Tuesday, four thousand dollars of deferred wear priced into a car as if it were sorted. Those are the things that turn a fair purchase into a bad one, and an hour on a lift finds nearly all of them.
Why we encourage it on our own cars. We publish a 168-point inspection on every vehicle we sell, and we still tell people to take it to their own shop if they want to. A seller's inspection and a buyer's inspection are different documents — ours tells you what we found and fixed, theirs tells you what an independent party thinks of the result. If those two disagree, you should know before you sign and not after.
Inspection cost, scope and turnaround vary by shop and region; ask before you book. Nothing here describes any manufacturer's specification or any shop's policy. Whether a specific fluid or component is checkable or serviceable differs by vehicle — your technician's judgment on that governs, not this list.
Related reading
- The first phone call A specimen call, transcribed, including where the inspection question belongs.
- What the history report misses Cash repairs, shops that don't report, and the two years it sat.
- Buying a car in winter What the cold reveals, what it hides, and which checks have to wait for a warm bay.