BWilcox

Hi Guys,

I had to fix a leaking cylinder head plug on my engine.

Before the "fix", the ECT sensor readings were normal. Please see the "normal" picture.

After the leaking plug fix, I filled the cooling system with new coolant and noticed some strange ECT behavior. Please see the "weird" pictures.

I have checked the wiring. No problems detected.

The engine coolant level is now stable. So I assume the system is packed with coolant and any air bubbles are long gone.

No error codes are reported.

The dash gauge appears to indicate the expected (180 F) temperature. I do not look at this gauge frequently while driving. So some observation error is possible.

Thoughts:

1.
The ECT values are not at end-limit values. So I have assumed the wiring is not intermittently shorted or open.

I have moved the wires around while data logging and do not see any response change that is associated with the wire movement. Vibration should not be an issue.

I have moved the wiring harness by the ECM (7730) and did not detect strange ECT readings.

Other things to try?

2.
Other sensors, IAT, EOT, and TPS seem ok.

3.
I forgot to turn on the heater.

Wonder if I need to get the coolant to run through the heater core to fully purge the coolant system of air?


Comments?


4.
Wonder if I have a gas bubble around the ECT location?

Running a TPIS MiniRam II.

Comments?


5.
What about a Thermostat that is not fully open?

My Thermostat opens (ideally) @ 170 F. Yes, I live in NC and it gets hot in the summer. This car is not a daily driver.

I noticed the ECT value seems to climb during longer runs and cool when at idle for a period of time. Just wonder if a partially open thermostat would restrict (too much) the coolant flow and result in partially higher short-term coolant temperatures?


Comments?

Thanks for any trouble-shooting suggestions.

Things were just fine a couple of weeks ago.

Best Regards,

Bruce

BWilcox

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