My thermostat reads 210 degrees on warm days. Should I be worried?

thermostats, summer

Dear Tom and Ray:

I'm part of the male population that, in the past, you have politely referred to as "anal-retentive" when it comes to car care. I'm getting better, though. Thanks to your sage counseling, I no longer shake the car to make room for that last 0.148 gallon of gas when I fill up. However, this one is killing me. I have an '86 Mercury Grand Marquis that runs great but is getting long in the tooth (224,000 miles). In order to keep a closer eye on things, I installed temperature and pressure gauges. Now I have to admit that too much information is a bad thing. At issue is the water temperature. At highway speeds, the temperature hovers around 210 degrees on warm days. This worries me, but since the car uses a 195-degree thermostat, maybe 15 degrees above the thermostat rating isn't so bad? Should I be worried? If not, what would be considered the point at which I should start worrying? -- Garry

RAY: When you see plumes of steam wafting up from your engine compartment, Garry.

TOM: Actually, you're nowhere near the worrying point. Worry when it gets up to 240 or 250 degrees.

RAY: Under pressure, antifreeze doesn't boil until it hits about 260. So, 210 is absolutely fine. You're in no danger of overheating this old beast.

TOM: But more importantly, Garry, I can see you've still got work to do. Are you staying with the 12-step anti-retentive program we recommended?

RAY: Or are you still stuck repeating the first step over and over again to make sure you've got it right? If so, it might be time to call your sponsor, Gar. Remember, one day at a time, baby.

Tags (Browse All)
thermostats, summer

You must be logged in to leave a comment. Login / Signup
Support for Car Talk is provided by:

Donate Your Car,
Support Your NPR Station

...and get a tax break!

Get Started

Find a Mechanic

Promo tile

Rocket Fuel