Thermostat issue??? (Page 1/1)
Barkaroo SEP 29, 03:25 PM
Hi to everyone!

I've had a coolant leak under the driver door recently which I have fixed. I burped the system successfully but my temp will only climb to 100 degrees or so. I am guessing it is my thermostat but I am having trouble removing it. Is there some trick to get it un-stuck? I am worried I will break it trying to remove it.
Gall757 SEP 29, 04:03 PM
Your thermostat will not limit your engine temp to 100 degrees, but if you do get it out you should replace it because the seal is most likely damaged.
It's more likely that there is still some air in the cooling system behind the sensor, and a little driving should take care of it.

[This message has been edited by Gall757 (edited 09-29-2019).]

theogre SEP 30, 11:03 AM
Is likely nothing wrong but iffy gauge lying.

Bleeding air is BS.
System will remove all air after gets a few hold/cold cycles. Just fill as directed in cave and other GM doc's.
Most times check air is gone after driving once to a few times just squeezing output hose and listen.
If system still has air then something is wrong letting air in. example small overflow tube or Rad cap letting air in even thru doesn't leak coolant. Air tight doesn't = liquid tight many times.

See my Cave, Coolant Fill

T-stat stuck is o-ring stuck to wall or worse, has weak/no coolant allowed rust in Tstat tube.
Remove. Suck out coolant enough to see inside of T-stat tube.
Get new Stant Superstat Thermostat in cave. Lube o-ring w/ brake or silicone grease before installed.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

SamanthaM SEP 30, 03:44 PM
Curious.......You mentioned an iffy gauge reading wrong? My 86SE v6 used to read 200 most of the time. Now for what ever reason it is reading around 160-180? I have no leaks and my coolant is good. My fan kicks on and off on the radiator as it should. I was considering a sensor issue or iffy gauge? I mean the car is 33 years old? I know my voltage gauge is off so it isn't unreasonable that the temp gauge is too?
Gall757 SEP 30, 05:45 PM

quote
Originally posted by SamanthaM:
I mean the car is 33 years old?



Fiero gauges were iffy when new....never mind the 33 years! They can be used for rough comparisons and that's about it. If one of them changes, check it out with a 'real' gauge.
theogre OCT 01, 02:07 PM
Yup.
Fiero uses same wiring as everything else but Fiero and many a very few others have Temp gauge w/ numbers that often reads BS right from the factory or soon after delivery to the first 1 - 3 years.

OP gauge and Volt gauge have problems too.
Even when gauges and senders are perfect... Any iffy wiring in the car can make them lie.

So you check w/ real tools to read at whatever.
IR to read T-stat house is quick check to coolant temp. Or use ECM scanner to read ECT sensor w/ much better accuracy.
Volt meter to read output for Alt and Battery directly.
"Shop" OP gauge on OP Port for that.

One crappy contact is enough and you have several for each gauge just in the dash to act up.
Example, I have OP reading high... Reading high, not pegged as sender disconnected. Over time... Replace/upgraded sender when that leaked and gauge still high. test w/ 45Ω at sender plug still reads high, etc, etc. Somewhere gauge still see extra 45+Ω but I stopped caring to find it. Even change the motor means I clean/fix many grounds etc to that and still OP gauge reads high.
Many have OP reading Low... Can be the iffy gauge too or a real problem that can kill the engine so always double check w/ a read gauge on OP port.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

SamanthaM OCT 01, 02:42 PM

quote
Originally posted by theogre:

Many have OP reading Low... Can be the iffy gauge too or a real problem that can kill the engine so always double check w/ a read gauge on OP port.




Thanks for the extra info.... I figured since I am getting the valve covers replaced today, I told the mechanic to run some checks for me. The volt gauge is off a bit, the tstat is good and the temp gauge is reading close to correct. He is going to run a test on the OP when he is done with the valve covers.
I also found out my speedometer is off about 2mph, but that one I don't really care about.

I figure while it is there, I can have him give me the "once over" so I know what else I have to look forward to replacing soon...lol
theogre OCT 02, 01:04 AM
Speedo off can be just tires have been replaced. Even Same size tires as factory tires from different makers or just different batches from one maker can change diameter enough. Even new vs. worn tires can effect the speedo.
If you use non spec tires, you will have speedo errors. How bad? run tire calc at miata.net etc to get in the ball park how higher or lower.

Note If compare to GPS... GPS speed can be off because is calc'ed in the GPS unit itself and not make to be a true vehicle speedo to start w/.

Also Fiero and others where built when most speedo's legally have ±X% of error.
I forget year charge but newer cars can legally read X high the actual speed but must never read lower in many countries not just in the US.
Speedo reads high then actual then cops won't stop you because Speed Limit isn't reached when Speedo = Limit.
Big issue when Speedo reads under actual speed... Cop love to stop speeders and many lawsuits for Car makers for installing speedo read wrong even w/ factory tires.
(Many newer cars can set Tire Size in PCM to correct Speedo errors and other issues but many owners never bother when buying big tires.)

Is part of why many cops don't bother stopping under 5mph over limit in many areas. But don't count on that in School Zones or even around town etc when Speed Limits are low. Low limits is common they can stop even 1 mph over...
tshark OCT 02, 11:44 AM
There are several areas where the PD decided to increase revenues by issuing citations AT 35 MPH IN A 35 MPH ZONE! Tickets ranged from $100 to $150. One such was an exclusive neighborhood, with affluent people. Was. The residents decided this was unacceptable, and issued an ultimatum: fix the law, or we will move. The PD chief is no longer in charge, but the practice remains. Most of the residents moved. Ticket prices increased, and people got ticketed for 34 in a 35. People avoided the area. Ticket prices increased, to $275. The area is now a ghost town. The roads are in terrible condition, and drug dealers are about the only people who go there. Nearby areas are going downhill.