Cooling
Overheating, leaks, pressure loss, water pumps, thermostat housings, head gasket confirmation.
Diagnosis Method
Learn the car first. Then fix what is actually broken.
A scan code tells you which system complained. It does not always tell you the root cause. Oni Repair sells diagnosis before parts — especially on GM vehicles where one symptom can look like three different repairs.
Overheating example
The head gasket question.
When a GM overheats, the wrong move is jumping straight to the most expensive repair. The right move is proving where the pressure, coolant, and contamination are going.
Check the oil
Milky oil changes the diagnosis. Clean oil means we look hard for external loss first.
Check coolant and pressure
Low coolant, pressure loss, caps, seals, O-rings, hoses, pumps, and housings all matter.
Confirm before quoting
Pressure testing and combustion gas testing help separate “maybe” from “confirmed.”
What we diagnose
Systems, not guesses.
Electrical
Windows, A/C, charging, sensors, water-damaged circuits, no-starts, key and ignition issues.
Engine
Rough idle, oil leaks, blue smoke, fuel trims, compression clues, PCV-related symptoms.
Fuel / no-start
Fuel pump, tank condition, battery, crank/no-crank, sitting vehicles, start-and-stall issues.
Customer script
What to have ready when you call.
A better phone call produces a better first visit.
Tell us
- Year, make, model, mileage
- What happened first
- What changed recently
- Any codes or warning lights
- What another shop already said
- Where the vehicle is located
Got a code?
Call before replacing parts.
We will use the code as the starting clue, not the final answer.