ESP8266 Automotive Head gasket leak detector

[Zim]

Years ago, we would sniff the radiator overflow bottle with a "four gas exhaust analyzer". If we detected HC (gasoline) in the bottle, it was a sure sign of combustion gases getting into the cooling system.

This would often cause poor performance, engine overheat, poor heater output. This was a valuable diagnostic technique to find leaking head gaskets.

Gas analyzers are very expensive, so here is my "poor man" approach. Video at the bottom...

- when turned on, unit will blink "blue" quietly for 30 seconds to allow sensor to stabilize

- unit will then wake up and blink green when ready to sample gases (circulation fan turns on)

- audible beeps and LED flashes will indicate detected HC gases.

                                                                                                                                                                              micro muffin fan

CODE: xxxx.bas

---

' Zim's Annex HC monitor V2  
CLS
GAS = ADC
D1=5:D2=4:D5=14
SPEED = 0
MAX = 0
PIN.MODE D1, OUTPUT    'is ground to buzzer and green LED
PIN.MODE D2, OUTPUT   'is ground to blue warming up LED
PIN.MODE D5, OUTPUT    'is an output to fan
PIN(D1) = 0
PIN.TONE D2, 1          'blinks blue LED
PIN(D1) = 1           'buzzer and green LED off
PIN(D5) = 0           'fan is off
PAUSE 30000        'wait for sensor preheat 
PIN(D5) = 1     'purge sensor with fan
PAUSE 5000
PIN.TONE D2, 0        'blue LED off
PIN(D2) = 1           'blue LED off
AUTOREFRESH 1000
TIMER0 1000, PROCESS
WAIT

PROCESS:
GAS = ADC
PAUSE 10
'wlog "gas", gas
SPEED = (GAS - 30)/450 * (30 - 1) + 1  
'wlog speed
IF GAS < 30 THEN LET SPEED = 1
PIN.TONE D1, SPEED 'flashes buzzer and green LED
RETURN

[Electroguard]

Very nice project, Zim.

Does that gas sensor only detect petrol, or could it also detect diesel ?

[Zim]

I will try it on diesel later today..

Thanks

[Zim]

Electroguard

No responce from diesel. I guess its not volatile enough...

Zim

[Electroguard]

Thanks for trying - and is still a very practical gas sniffer project for whatever gas sensor is used.

[cicciocb]

Interesting idea. What is the sensor used in the project ?

[Zim]

Hi cicciocb

sensor is MQ-2

Zim

[cicciocb]

Thanks Zim