[brighton911]

My case was different but may be of interest. My car was very slow to warm up, and during colder weather, never got close to normal operating temps. So I pulled and tested the engine thermostat. Right on Q, the thermostat would open at the specified temp so I put it back in. No change. Not one to spend money needlessly yet knowing despite the evidence the that showed the thermostat OK, I replaced it. Now it warms up quickly and stays right on the first mark even through a considerable ambient temperature range. Doesn't make sense but that was my finding.