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cylinder head temp sensor

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Old 09-10-2021, 06:57 AM
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Rabs
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Default cylinder head temp sensor

Have a cold start issue - can anyone help by explaining how I check if this sensor is working correctly? Thanks
Old 09-10-2021, 09:22 AM
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Rocket Rob
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The cylinder head temp sensor tells the DME the temp of the engine. When its cold, it richens the mixture. A faulty sensor can cause the engine to run poorly when cold.
Old 09-10-2021, 10:11 AM
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No_snivelling
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You can test the cylinder head temperature sensor with a scanning tool like Scantool, Durametric, PDT999, UDT999 or the Porsche Hammer if you can get your hands on one.
It will provide actual temperature values.
Old 09-10-2021, 10:56 AM
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cjoenck
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Measure resistance between terminal 45 and 30 on the DME plug or directly at the sensor cable. You should get between 1.4 and 3.6 kOhm at 15-30C ambient temperature. At 40C you should be at 1-1.3 kOhm and at 80C you will be at 250-390 Ohm. If you get 0 Ohm or infinity your cable is shortened out or broken. You find details in the workshop manual in volume 1 under DME diagnostic/troubleshooting.
Old 09-10-2021, 11:51 AM
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darylbowden
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Originally Posted by No_snivelling
You can test the cylinder head temperature sensor with a scanning tool like Scantool, Durametric, PDT999, UDT999 or the Porsche Hammer if you can get your hands on one.
It will provide actual temperature values.
^^ if your cylinder head temp sensor is bad it'll be immediately apparent in the readout of the Hammer. It'll be bouncing all over the place or some NaN type number, etc. It will be really obvious.
Old 09-10-2021, 12:03 PM
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cjoenck
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Not everyone has a Hammer so reading internal resistance with a multimeter is straight forward, easy, and reliable.
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