Thermostat takes about 3 miles / 5 minutes to open

Messages
1,574
Location
Alamo, CA
Is this normal? I get on the freeway and can see the temps rise to near high than open , dropping back to normal after about 3 miles/ 5 minutes from start.
 
Messages
1,383
Location
Agrestic, CA
I've never seen a temp gauge overshoot the "normal" range and then return to normal. My guess is that your thermostat is taking longer to open and may be going bad. How old is the vehicle and what is it?
 
Messages
1,383
Location
Agrestic, CA
Quote:
Every brand new stant I've put into my Dad's Blazer overshoots then returns to normal.
Really?!? I've owned quite a few cars in my life and have never had that happen to me. Although I have never used a stant brand thermostat. That doesn't seem like it would be a good thing to me.
 
Messages
1,383
Location
Agrestic, CA
Quote:
However, it doesn't go to high! It goes to about 215 then drops to 195 and stays there.
Still, I would think that the ideal situation would be for the needle to only move until it hits 195 and then stops.
 
Messages
6,171
Location
Santa Barbara, CA
My '68 Volvo 122s overshoots then drops to "normal". My '93 MX6, that I just replaced the OEM factory stat with a Stant 2 days ago, warms up the exact same with the new Stant thermostat. Could be a sensitve temp gauge, or a slow thermostat.
 

m2200b

Thread starter
Messages
1,574
Location
Alamo, CA
Sounds better to replace as its got several years. I can't recall ever seeing it attract my attention before so I assume it had been just going up and then leveling off rather than peaking and then going down. Its a 1991 B2200 Mazda so it should act like surfstars MX6 Mazda .
 
Messages
6,171
Location
Santa Barbara, CA
When in doubt, throw parts at it To clarify, (after re-reading my above post) the new Stant and old OEM Mazda thermostat warm up and level off. They didn't behave as my old Volvo's stat does.
 
Messages
4,009
Location
Calgary Canada
My chev k1500 used to overshoot at about 3 miles then drop to a mid-cold level. The needle would then go up and down like this a few times (dropping to a higher low-level each successive time) until it would settle at and hold the final operating temp. I think this would be pretty normal if you have a large radiator with significant cooling capacity. The cool water from the radiator really makes a significant temp differential the first few times the thermostat opens. I think this considered normal for many cars.
 
Messages
1,383
Location
Agrestic, CA
Quote:
My chev k1500 used to overshoot at about 3 miles then drop to a mid-cold level. The needle would then go up and down like this a few times (dropping to a higher low-level each successive time) until it would settle at and hold the final operating temp. I think this would be pretty normal if you have a large radiator with significant cooling capacity. The cool water from the radiator really makes a significant temp differential the first few times the thermostat opens. I think this considered normal for many cars.
Learn something new everyday. However, if this is a new behavior I would throw a new thermostat in there. It probably needs replacing by now anyway and we aren't talking a lot of $$ here. Should be easy to do on the Mazda.
 
Messages
4,009
Location
Calgary Canada
I agree with Lou, a change in behavior could indicate a problem. Thermostats are cheap, and if the one in there fails (and doesn't fail in the open position) then your best possible case will be be a very inconvenient situation. Better to sort it out in the comfort of your garage when you feel like it than to HAVE TO deal with it on the side of the road when you're late for work.
 
Top