Question about my mercury tracer...

Today I noticed that the temp gauge needle doesn't reach the level it used to. It sits way too low. The heat on the car isn't that warm anymore either.

What on earth can cause the car never to fully warm up? Bad thermostat? I checked the radiator fan, it isn't constantly running that I can tell... Could possibly be a gauge problem, but it seems like the heat isn't where it used to be either so I tend to believe the gauge is correct and that the car just isn't warming up.

I'm guessing thermostat, not sure what else it can be. ?

J

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Best in Show - NG07
2010 - 6G74/3.5L E16Gs - 688awhp/679awtq (Race+Meth)
2011 - 6G74/3.5L 68HTAs - 740awhp/762awtq (Race+Meth)
2013 - 6G74/3.5L MTC Stage4 - 908awhp/832awtq (Race+Meth)

A faulty thermostat is the place I would check first. The part is cheap and almost certainly very accessible. Give that a shot, I would bet it fixes the problem.

Matt

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1993 Sandstone Gray Metallic VR-4 (1 of 56)
11.77@122
11.76@119

I'm almost 100% sure it'll be your thermostat. It probably just failed open. Which is a good thing.

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~Joe - aka spider gear destroyer
'94 Stealth R/T
-Lightly Modded ;)

You're going to have to drain some of the coolant to replace the thermostat (might as well drain it all). When you refill it, put more coolant in than water. Chances are, the coolant going thru the system in that car hasn't been flushed recently (if ever). Fresh coolant will make the heat work much better.

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06 Blue EVO 9

If the car NEVER heats up, then it probably isn't a bad thermostat. If it just takes LONGER to heat up, then it is probably a bad thermostat. A bad thermostat stuck "closed" will cause your car to overheat, and a bad thermostat stuck "open" will just make it take longer for your car to heat up, but it will eventually heat up.

There could be an issue with the heater core (maybe it is partially blocked). This doesn't explain the temp sensor though. It may be that the thermostat is stuck partially open, so flow is restricted enough to prevent the car from overheating, but also limiting flow to the heater core to prevent it from heating up properly?

The car would probably benefit from a coolant flush and fill (~$60). This will allow for better heat transfer from the block and to the heater core. A higher percentage of coolant (such as 60% antifreeze to 40% water) will allow the car to run warmer than a 50-50 mix.

Brad

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Brad
92&93 RT TT

Mods:
TD04L 13T's | Alamo Side Mount Intercoolers | RC 550 cc injectors | Supra fuel pump | SBC DXD 6-puck | 3SX Poly Motor Mount | TySpeed DP w/ TP | custom Magnaflow exhaust | DSBC | S-AFC | + much more

The coolant will NEVER reach normal opperating temperature without the thermostat regulating the coolant temp. Try popping the 'stat' out of your stealth and drive it around for 30 minutes. Sure, the air will be warmer than the 30 degree air outside, but the coolant will never get close to reaching the 180 degrees it would normally be regulated to. You'll be lucky to get even close to that with the cold air temps while the car is moving. I know this for a fact as I took my thermostat out for a couple weeks to see if the old 'muscle car' trick would benefit us. Which it didnt. All it did was cause the comp mess with my idle in attempt to raise the engines temp into normal range. I never hit a coolant temp about 150 degrees while cruising, and this was in 70 degree outside temps.

If the Temp reading is normal, than you could check the heater valve. It may be faulty and not allowing the coolant to flow into the heater core. But in this case, the temp reads low, so the coolant could be getting perfect flow into the core.
Its just not being held in the engine long enough to absord the engines heat. This is not good for alluminum engine parts because they do not take the heat as well as iron parts without a properly regulated cooling system.

But I do recommand a flush either way. It cant hurt, especially when 90 degree summer temps roll around.

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~Joe - aka spider gear destroyer
'94 Stealth R/T
-Lightly Modded ;)

so on my way to pickup a thermostat from hiller ford ($14), i notice the temp gauge is reading fine again. and, since then, it's still been reading fine. i also get plenty of heat now too. weird, maybe the thermostat is acting flaky and on it's way out. i guess i should change it regardless...

_________________

Best in Show - NG07
2010 - 6G74/3.5L E16Gs - 688awhp/679awtq (Race+Meth)
2011 - 6G74/3.5L 68HTAs - 740awhp/762awtq (Race+Meth)
2013 - 6G74/3.5L MTC Stage4 - 908awhp/832awtq (Race+Meth)

..

could be air in the hoses causing problems. A flush and fill with the new t-stat should fix erallup.

I would still change it and flush out the system. Its a small price to pay versus freezing your toes off. Or worse, having it fail shut and overheat the motor.

_________________
~Joe - aka spider gear destroyer
'94 Stealth R/T
-Lightly Modded ;)