Thermostat Stuck Open? 2001 Venture
GregA
11-13-2006, 01:33 PM
Hi Folks,
While driving my van to the airport a few weeks ago (2001 Chevy Venture) I noticed something strange - the Temperature gauge was at the BOTTOM of its range, or VERY low. I had noticed that the temperature gauge DID started to rise at the beginning of my trip, and I had the heater on because it was kind of cool that morning (about 50 degrees F).
Anyway, the gauge stayed pretty low throughout the trip (about 30 minutes @ 60+ MPH), and the heater was NOT working as well as I think it should have (I had to turn the temp control dial all the way up to get any warm air).
On the way home from the airport a few days later, the gauge seemed to be stuck low for a while BUT then suddenly came up to about 1/4 scale on the gauge (where it "normally" sits).
So here is my question: Could it be that the thermostat is stuck (or sticking) OPEN?
Normally I would just change it, but on this van that can be a bit of a pain because the thermostat housing is not exactly "in the clear" or easy to get at. So before I tackle this job I would like to get a couple of other opinions.
All input is appreciated.
Take Care,
While driving my van to the airport a few weeks ago (2001 Chevy Venture) I noticed something strange - the Temperature gauge was at the BOTTOM of its range, or VERY low. I had noticed that the temperature gauge DID started to rise at the beginning of my trip, and I had the heater on because it was kind of cool that morning (about 50 degrees F).
Anyway, the gauge stayed pretty low throughout the trip (about 30 minutes @ 60+ MPH), and the heater was NOT working as well as I think it should have (I had to turn the temp control dial all the way up to get any warm air).
On the way home from the airport a few days later, the gauge seemed to be stuck low for a while BUT then suddenly came up to about 1/4 scale on the gauge (where it "normally" sits).
So here is my question: Could it be that the thermostat is stuck (or sticking) OPEN?
Normally I would just change it, but on this van that can be a bit of a pain because the thermostat housing is not exactly "in the clear" or easy to get at. So before I tackle this job I would like to get a couple of other opinions.
All input is appreciated.
Take Care,
Glen_T
11-14-2006, 01:25 PM
If it's never been replaced, I would suggest replacing it. Your symptoms sound just like a bad thermostat, and if you have many miles on it, the wax motor inside it is probably going bad.
To check, if you've driven it quite a bit and the upper radiator hose is still pretty cool, then I'd say the t-stat is stuck open. One other thing would be that the fans are both on full blast and perhaps overcooling the coolant, but I'd think you would notice the noise......Good luck, Glen
To check, if you've driven it quite a bit and the upper radiator hose is still pretty cool, then I'd say the t-stat is stuck open. One other thing would be that the fans are both on full blast and perhaps overcooling the coolant, but I'd think you would notice the noise......Good luck, Glen
GregA
11-14-2006, 09:20 PM
Thanks for the input Glen.
I am having my son change the thermostat & flush the cooling system tomorrow during his "Auto Tech" class (free labor :grinyes: ).
The fans seem to be working fine, both low & high speed. And since the temperature sensor is right by the thermostat, I would think that any coolant coming through the engine would have time to get pretty warm once it reaches the sensor.
I "gathered some data" on the coolant temperature the other day through two cycles of the system (until the fans kicked on). I am going to stick the data into a spreadsheet and plot it out. Maybe you would be interested in it?
To summarize, the fans turn ON (low speed) at about 226 degrees and back OFF at about 210. BUT - if I turned on the defroster (turns on compressor & fans), the coolant temperature would dip down to about 172! I just don't think it should dip that low with a 195 thermostat.
I will let everyone know what happens.
Take Care,
I am having my son change the thermostat & flush the cooling system tomorrow during his "Auto Tech" class (free labor :grinyes: ).
The fans seem to be working fine, both low & high speed. And since the temperature sensor is right by the thermostat, I would think that any coolant coming through the engine would have time to get pretty warm once it reaches the sensor.
I "gathered some data" on the coolant temperature the other day through two cycles of the system (until the fans kicked on). I am going to stick the data into a spreadsheet and plot it out. Maybe you would be interested in it?
To summarize, the fans turn ON (low speed) at about 226 degrees and back OFF at about 210. BUT - if I turned on the defroster (turns on compressor & fans), the coolant temperature would dip down to about 172! I just don't think it should dip that low with a 195 thermostat.
I will let everyone know what happens.
Take Care,
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