Thermostat Check? - Toyota Nation Forum : Toyota Car and Truck Forums

jon1000 · 10-30-2010, 02:21 PM

How can you tell if a thermostat is stuck part of the way open. It seems the car (2000 V6 LE) is taking a bit too long to warm up. I does get to normal range eventually. This will be the first winter with it and I don't want to change it after it gets cold.

Thanks in advance.

deadrx7conv · 10-30-2010, 02:23 PM

If its more than 5 years old OR if its not a Toyota thermostat, change it out.

The boiling it on the stove method to see if it opens is overly used and not at all accurate for testing a thermostat.

***LynchburgCSI*** · 10-30-2010, 08:14 PM

Sounds like it may be stuck open or closed (which ever sends coolant to the radiator 24-7). If it takes FOREVER to heat up, that's probably because it's sending coolant to the radiator ALL THE TIME... cooling COLD coolant.

Just swap it out with a TOYOTA OEM unit.

***fenixus*** · 10-31-2010, 01:36 AM

how much time does it take to warm up and under what conditions (idling or light driving) from cold start?

jon1000 · 10-31-2010, 12:18 PM

It took 2.9 miles from a cold (48 Deg.) start at 30-35 MPH. doesn't sound like much, but that is a lot longer than it used to. A lot of that is at a higher RPM because the tramsmission wont shift into third unless it is warm enough or the car reaches 35 MPH.

Toyota in my area has bad hours so I couldn't get another thermostat or might haave doneit toaday.

***JohnGD*** · 10-31-2010, 01:14 PM

Thermostats are not tested and reused. If it's suspect just replace it. The only reason you might test it is to verify its operation. It's just not worth the time and new coolant to reuse an old thermostat/gasket.

48 deg F is not that "cold".

So see how a new thermostat (Kuzeh made most likely) and gasket helps. Don't use an aftermarket thermostat here. I've never seen one that's decent for domestics or imports. Refill using Toyota Red and distilled water only.

Quote:

Originally Posted by jon1000

It took 2.9 miles from a cold (48 Deg.) start at 30-35 MPH. doesn't sound like much, but that is a lot longer than it used to. A lot of that is at a higher RPM because the tramsmission wont shift into third unless it is warm enough or the car reaches 35 MPH.

Toyota in my area has bad hours so I couldn't get another thermostat or might haave doneit toaday.

Solid_Koolaid · 10-31-2010, 02:21 PM

I know it's already been said in this thread many times but I add my share : use an OEM thermostat

I never ever had good experience with any aftermarket unit in both my 95 Tercel and my 90 Celica (had the 5SFE).

In the Tercel it would take WAY too long to warm up. In the Celica, it would not react fast enough and revving the engine to the redline would cause a drastic drop in coolant temperature (water pump spinning much faster + bad aftermarket thermostat).

In both case, switching back to Toyota OEM solved the problem.

BTW I don't get why something as simple as a thermostat can't be made to work correctly by an automotive aftermarket company, like... what the f*** men ?

***TrailDust*** · 10-31-2010, 03:05 PM

Quote:

Originally Posted by solid_koolaid

btw i don't get why something as simple as a thermostat can't be made to work correctly by an automotive aftermarket company, like... What the f*** men ?

+1

snigma · 11-01-2010, 09:11 PM

My 98 5S-FE has the same problem: Needle is halfway to the middle, and heat blows lukewarm even at 40F ambient.

I noticed that there are OBD-II codes for it:

http://www.obd-codes.com/p0128
http://www.obd-codes.com/p0125

Shouldn't the ECU throw these codes if the thermostat has failed? From searching the forums, it seems that the ECU never throws these codes but the heat is working again after a thermostat replacement.

***LynchburgCSI*** · 11-01-2010, 09:19 PM

Just because a code exists, doesn't mean that the car has the sensors for the ECU to pick up a fault. If that makes sense. I've never had a code thrown on a camry from a thermostat stuck open or closed. Just issues with it heating up or over heating.

dave1811 · 11-01-2010, 09:44 PM

If you don't absolutely need it today, I ordered my thermostat for my 99 last Monday on 10/25 and got it today via UPS along with hoses, clamps, and some other odds and ends from Toyota Parts Zone. They seemed to have really good service. The factory thermostat was like $14.62 plus $3.89 for the gasket which goes around the thermostat. Came today in the factory Toyota box.

My 2 cents.