Originally posted by DemonSVT:
Correct.

When the A/C is on it runs both fans 100% of the time. That is why the ECT is lower.

I would hope your 3L does not run hot enough to run both fans all the time. That would be a normal operating temperature over 227 degrees!

If it does you have serious other issues.




My understanding is that both fans are running above 214-215 degrees which is consistent with the conditions described. The hottest recorded temperature I have observed using my ODB-II data logger is 221 but the engine temp averages about 215 degrees. I have an autometer water temp and oil temp gage and the stock gage all pretty much agree on temps. I was concerned that my stock ECT gage sender may have been faulty and replaced it not too long ago and it still reads well within the normal even with both fans running. And trust me, I can tell when one or both fans are running. They're pretty loud.

Just as a side note, I replaced the ECT temp sender that feeds the PCM.

As far as the type of conditions...it doesn't matter. It could be stop and go traffic or highway cruising and the temp will still be about 10 degrees cooler.

Curtis 3L 'Oval Port' 98 Black SVT 180.5HP/178lbft '03 Black Sport Trac