Normal
Idle speed holds steady.
New in version 2.0
AcceloVibe
Your engine's pulse.
An idle reading from your iPhone. No tools, no wires.
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No tools. No wires. Nothing plugged into the car. Put your iPhone on the hood, let the engine idle for about thirty seconds, and see if the idle holds.
How it works
-
01
Tap Start Test.
Pick the length. Thirty seconds is the usual. You can also choose 10, 20, or 60.
-
02
Set it on the hood.
A three-second countdown gives you time to place the phone on the center of the hood, in a non-slip case.
-
03
Hands off. Engine at idle.
The iPhone motion sensors read the vibration and turn it into engine speed, using the engine type and cylinder count you entered.
-
04
Read the idle.
A plain answer, the numbers behind it, and the graphs. Saved to that car.
Watch
Thirty seconds
on a real hood.
Save the car. Choose thirty seconds. Step out, tap Start Test, and set the phone down. The app does the listening.
Readings
Four plain answers.
Every test ends in one color. Green, orange, and red describe how much the idle speed is moving. Gray means the signal was not clean enough to score.
Caution
Idle speed is moving more than usual.
Attention
Idle speed is moving a lot.
No reading
The signal was bad. Try again.
The numbers behind it.
From a 2016 Subaru Crosstrek at idle. One phone, one hood, thirty seconds.
Engine speed
0RPM
Worked out from vibration alone. Nothing connects to the car.
Firing frequency
0Hz
Rotational frequency
0Hz
Speed fluctuation
0%
Graphs
Vibration by frequency. Engine speed across the test.
Turn on harmonics to see the vibration lines around the firing tone.
Version 2.0
Every screen, rebuilt.
Your cars
Every car gets
its own file.
Save the make, model, year, and car ID, with a photo, color, and odometer. Each test lands on the right car.
The same car, again
Know its
usual idle.
After five scored tests, a new reading is compared with that car's usual idle. You see where today sits against the rest.
A report you can share
Two pages.
Take it with you.
-
The whole reading, on paper.
Share a PDF from any saved test. Bring it to the seller or the mechanic.
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The answer first.
The car, the date, and one plain line: "Idle is steady and clean. Speed held at 845 RPM, give or take 3."
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Measurements.
Engine speed, firing and rotation frequency, RPM variation, peak width, phone tilt, and signal strength.
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Against this car's usual idle.
Today's speed placed on the range from that car's earlier tests. Usual idle 812 RPM. Today is inside the range.
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Vibration by engine order.
Each bar is vibration at a multiple of engine speed. The firing order is the expected peak.
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Across saved tests.
How one order moves from test to test, so a change stands out.
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Engine RPM over time. Full spectrum.
The speed trace across the test and every vibration line from 0 to 50 Hz.
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What it shows. What to do next.
Plain notes on the reading, and when to test again in the same conditions.
The film
Buying a used ship
on Titan V?
Some sellers smile a lot. The idle does not. Know before you buy.
Before you start
Six steps
at the curb.
Engine at idle, phone on the hood, you outside the car.
- 01Park away from traffic, on a flat surface, with the parking brake on. Start the engine and leave it at idle.
- 02Save the car in the Car screen: make, model, year, car ID, engine type, and cylinder count.
- 03On the Test screen, choose the length. Thirty seconds is the usual.
- 04Step out of the car.
- 05Tap Start Test. During the three-second countdown, place the phone on the center of the hood. Use a non-slip case.
- 06Leave the phone still until the timer ends, then review the reading. Share the PDF from the saved test if you want a copy.
A reading, not a diagnosis.
AcceloVibe does not connect to the car and does not read vehicle systems. A warning light, a noise, a leak, or a repair decision belongs with a mechanic.
Safety
- Do not use while driving.
- Flat surface, parking brake on.
- Stay outside the car during the test.
- Engine at idle only.
- Phone in a protective, non-slip case.
- Park away from moving vehicles and traffic.
Limitations
The reading is supplementary information from vibration, not a definitive assessment of engine condition. The make, model, and year you enter are for your own reference, so tests of the same car can be compared.
AcceloVibe is provided "as is" without warranties of any kind.