Nobody walks out to their car in the morning and thinks “my crankshaft position sensor has failed”. They think “it won’t start”, or “there’s a puddle under it”, or “it makes a noise when I turn”. These guides work the way you actually experience a fault — from the symptom back to the cause.
Browse by Symptom Type
The Four Questions That Narrow Almost Any Fault
Before you search anything, answer these. They eliminate most of the possibilities on their own, and they are the first things a good mechanic will ask you.
- When does it happen? Cold start only, once warm, at idle, under load, at a specific speed, only when turning, only when braking. A fault that appears only when cold is a very different list of causes from one that appears only when hot.
- Is it getting worse? A noise that has been the same for a year is lower priority than one that appeared last week and is now louder.
- Does anything change it? If a vibration disappears when you press the clutch, or a noise changes pitch with road speed rather than engine speed, you have just narrowed it to a handful of parts.
- What changed just before? A service, new tyres, a pothole, a jump start, fuel from an unfamiliar station, or a cold snap. New faults very often follow recent events.
Latest Troubleshooting Guides
All problem guides ›-
Transmission Whines in Reverse Only: Causes
A whine or hum specifically while backing up — with reverse otherwise engaging and working completely normally — is a distinct, usually…
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Car Smells Like Exhaust Inside the Cabin: What to Do
An exhaust smell inside the cabin means exhaust gas — potentially including carbon monoxide — is reaching the space you’re breathing in.…
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Exhaust Ticking or Popping Noise at Startup: Causes
A ticking or popping sound from the engine bay that’s loudest right after startup and fades as the engine warms is a…
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Grinding Noise When Turning the Steering Wheel at Low Speed
A grinding sound that only shows up while turning the wheel at low speed — pulling into a parking space, making a…
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AC Blows Cold on One Side Only (Driver vs Passenger)
On dual-zone systems, a temperature difference between sides is usually a mechanical door problem, not a sign the AC system itself is…
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Car Won’t Go Into Park: Causes
Park uses a completely different mechanical system from every other gear — a dedicated pawl that physically locks the output shaft, which…
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Brakes Feel Spongy Only on the First Press of the Day
A pedal that’s soft only on the very first press after sitting overnight points somewhere different than the general soft-pedal causes covered…
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Engine Runs Rough Only When Cold: Causes
An engine that runs rough for a few minutes and then smooths out entirely is telling you something specific — the fault…
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Car Vibrates When Idling in Drive But Not in Park
This is a third, distinct pattern from two other guides on this site — sustained vibration specifically while sitting in gear, not…
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Car Stuck in Limp Mode: What It Means and What to Do
Limp mode is the car protecting itself, not breaking down — but driving through it without diagnosing the trigger just delays finding…
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Power Windows Won’t Work: Causes
Whether it’s one window or every window completely changes the likely cause — narrowing that down first saves real diagnostic time.
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Whistling Noise From the Engine: Causes
A whistle is usually loud enough to actually pinpoint by ear — and it often explains a lean-condition code that would otherwise…
Chock the wheels, use axle stands rather than a jack alone, let hot components cool, and disconnect the battery before touching wiring. Brakes, steering, fuel lines, airbags and the orange high-voltage cabling on hybrids and EVs can cause serious injury or death if handled incorrectly. If a job is beyond your tools or experience, stop and book a qualified mechanic — there is no shame in it and it is always cheaper than the alternative.