Okay so I've been noticing that my car has been running at low temperatures lately. I first noticed it on my way home from WI a few weeks ago with my buddy. We were driving about 80mph with a few bursts to 120mph or so (he has a '99 SS). Anyways, I noticed my coolant temps were at like 122-124 and I was kinda confused.

Today on my way home from Nic's, I noticed again my temperature got no higher than 130*F (based on datalogging) with most of it being 120-124ish. This is a 35-40min drive at 35-45mph. It seemed when I was going faster it was a bit lower and when I was going slower it got a bit higher.

Is it just me, or does it sound like my t-stat is stuck open? I wonder if it could be...that would be another possible reason I've been failing emissions with slightly high HCs.

Tomorrow I'll start it without the radiator cap to see if I see coolant moving.

If I have to change the t-stat...how much of the coolant do I have to drain to install the new t-stat? Just to get it 2" or so below the top of the radiator? Also, should I just replace it with the 195*F t-stat I bought awhile back (and has been sitting here) or should I try to find one that would run a bit warmer for emissions help?

 

How about your temperature sensor?

 

A new t-stat costs five bucks.
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I suggest no higher temp, than a 180.
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Test it in a pan of hot water, to make sure it opens.