I have to watch my number 3 cylinder because it always seems to be 20 degrees hotter than the other 3 on climb out and stays 20 degrees hotter in cruise. I have an IO 320 in an RV9. I don't know why I haven't checked it before, but I looked at it today when the engine was cold. 1,2, and 4 were 73 degrees and 3 was 92. Do I just need a new sensor? Maybe I haven't looked at it before because when reading other posts, #3 always seems to be a problem, so I just assumed the same. In me pre take-off I look at the oil temp, then I don't watch the cylinder temps until I am in climb out.
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Cylinder #3 is hot (even when the engine is cold)
- Thread starter Coryb
- Start date
You can always disconnect it from the harness, swap with the #1 sensor and see what happens.
If #1 is 20° hotter and #3 is normal, then it's the sensor. If #3 remains 20° hotter, then it's the harness wiring back to the EMS/EFIS. If the problem goes away, then it was the connections at the probe-to-harness.
If #1 is 20° hotter and #3 is normal, then it's the sensor. If #3 remains 20° hotter, then it's the harness wiring back to the EMS/EFIS. If the problem goes away, then it was the connections at the probe-to-harness.
I had a very similar problem. #3 as well.
1. Start by disconnecting the probe to the harness. Plug it back in and check. Mine cleared, but I replaced it anyway.
2. Swap #1 and #3 at the harness and see if the temp follows or stays with the probe to #1. If so, replace it.
3. If the temp stays with #3, it's not the probe. Not likely.
1. Start by disconnecting the probe to the harness. Plug it back in and check. Mine cleared, but I replaced it anyway.
2. Swap #1 and #3 at the harness and see if the temp follows or stays with the probe to #1. If so, replace it.
3. If the temp stays with #3, it's not the probe. Not likely.
