Thermostat vs temp help???

[Bottomlesspit]

Hey guys,
Last month i installed a new 195* thermostat when I installed my Autometer mechanical water temp guage. I filled the radiato with Prestone Ready mix anti freeze.
I have never used the pre mixed stuff before. The car has a stock radiator in it with stock clutch fan and shroud.
This is the same setup I had on my built 93GT and it worked great.
Last month after installing it the temps always read a max of 195 even when temps got near 100. A lot of the time the temp would read around 190.
Now that the temps have dropped the water temps are even lower. Tonight while driving home the outside temps were in the mid 50s. The temp guage maxed out at 180*, even after driving for 30 minutes.
This all seems way too cold. I also noticed the heater, put on full hot, really only blew nice warm air. I drove home and in the 30 minutes I had the temp on full hot and the blower set on the 3rd position...never got but warm inside. If I had done the same in my 93 i would have looked like a piece of burnt toast by that time!
Is the pre mix stuff any part of the problem? Maybe my 195 thermostat not really a 195? My car's ancient cooling system a superior system Ford snuck into my car during the build?!!! Maybe my readings are norma?
Looking for some insight into this issue before I start pulling parts again. I have enough issues already that I'm working on, so I really don't want to have to start pulling parts again.
BTW, the mechanical sender is mounted in the water neck, just inside of the thermostat, so the temp readings are pretty accurate.
Thanks for any help or ideas.
Ken

 

[Fox8950]

No chance you put the thermostat in backwards is there? Only reason I ask is these motors have one of the few therm. housings you can actually physically fit the thermostat into backwards and the last 2 stangs I bought when I tore the motors down this was an issue and gave me the exact symptoms you are talking about.

 

[5spd GT]

I am not sure on the accuracy of the guage mounting location, so I would not comment on that.

I will say, that the thermostat typically has the number (like Motorcraft) of degrees the thermostat is rated at.

I know my heater never got hot in my '93, and I had a 180* thermostat.

 

[HISSIN50]

If you used a performance t-stat, that can cause reduced temps. The extra jiggle valves or bleed holes allow coolant to pass while the stat is closed, and balanced stats open sooner by design.

Like David, I haven't put a gauge sender in the t-stat housing and also cannot comment. There can be issues with this because if the stat sticks closed, your gauge won't alert you to the increased motor temps with any reliability. Most of us use the stock sender location for the aftermarket gauges, so this is our point of reference. That said, I've observed ECT's in real time, and a calibrated ECT is within 2*F of an aftermarket gauge (in the stock sender location) above 170*F on my car.

A point of reference perhaps: With a balanced 180*F stat, I can have gauge readings settle at 165* when it's cold out (50's) and I'm moving at 50 mph for a period of time.

The 50/50 mix is fine. The premixed stuff is fine too. Especially in Texas. Remember, water rejects heat ~2.6 times more effectively than E/G coolant, so you being fat on coolant only helps in the winter (and is why in the summer, sometimes we drop stoichiometry down to 25/75 coolant/water, respectively).

Ken, If you actually fix this, next summer you will be running hot I fear. If you are confident in your gauge readings (and know you are really running cool), have you considered shrouding part of the radiator? This will lower the heat rejection ability of the system and bring temps up. You've seen big rigs do this I'm sure.

I think at a minimum, if this is a non-perf stat, I would pull it and boil it. The boiling test isnt completely valid because it's not as rigorous as the conditions the stat sees in the car (If we could boil stats at 16 PSI, with water slamming vigorously against the pellet, this would be a more accurate test). But if it fails the boiling pot test, you know it's toast.

Good luck bud.

BTW, I recently picked up a donor car for a family member. I thought of your car as I have been 'unwiring' some of the circuits. I cannot believe what some people do in their spare time. Imagine if they fix their houses the same way.

 

[tuhockey11]

I have been having a similar problem. Granted Im using the stock gauge, but I bought the car with a 180 stat, just put in a brnad new 195 stat, and nothing has changed. I installed the stat the same way the other was was installed, assuming it was correct. Which is the correct way for it to face?

 

[PUNISHER RACING]

I feel with the colder weather the engine doesn't get a chance to make it to 195 to let it open fully I have a 180 in my dd and the Autometer never reads over 150 degrees ever , I actually drove it to work this fall and never flipped the switch for the fan. Try blocking some of the rad. with cardboard and see if that lets it get warmer. I have yet to see a stocker 5.0 that will run hot(near 200 degrees)

 

[HISSIN50]

I have yet to see a stocker 5.0 that will run hot(near 200 degrees)

Drive one in 115* ambient temps.

 

[PUNISHER RACING]

that would problably do it!! At 115 I ain't leavin the house for nuttn'

 

[Bottomlesspit]

Thanks for the replies eveyone.
I am sure the stat is installed correctly. I have done it a zillion times and I doubled checked the maintenance manual just to be sure when I did this one.
Maybe my temps are a non-issue, don't know. My main concern is I know the peak efficiency for these motors is around 210* so I don't want to run too cool.

I don't see the issue with having the temp probe in the water neck. Matter of fact, back with my 93 years ago in my past life, that was THE place to put it. About everyone on this board...all the old timers all recommended that location. I guess times have changed? It seems in this location I can: 1. see when/if the thermostat opens, 2. I'm getting a direct temp reading of the coolant right as it comes out of the motor. That was the old thinking anyway.

The thermostat I got isn't anything special. It was just listed as a 195* and has the bleeder valve at the top.

Hissin...I feel your pain. I am about 1/2 way done with the interior now. The wiring is unbelievable. The 10yr old must have had his friends over for play-day under the dash?! Right now I have 14 loose wires hanging down from under the drivers side dash?! Yes, I still have to drive it daily to work too. My feet get all tangled up. I have no idea where these wires go, so it's taking forever to trace each one. I know one must have something to do with the Oil pressure light, because everytime I press the clutch in the oil px light pulses! Oh what fun!

Thanks again for all the responses.
Ken

 

[HISSIN50]

The thing that worries me about having the gauge sender in the t-stat housing is that if the stat sticks closed, the gauge wont let you know very quickly that engine temps are skyrocketing (since the closed stat acts as a bit of a bulkhead).

For the same reason, sometimes the gauge readings are a little off as the car warms up (when the stat is closed). I have my OEM sender in the stat housing on the 94 (there's no rear port on the back side of the driver's-side lower intake, or I'd have put it there, as I did on the '88).

With the way you cycle through stats, even if any of that theory is valid, you shouldn't have any stats sticking closed.



I do find it weird that you run so cool with a generic (unbalanced) t-stat. They tend to really not even start to open till their rating. Then they can take an extra 10-15*F to open fully. Conversely, the balanced stats often start to open a little sooner than their rating and are pretty wide open by their rated temps.


I once did my own BS testing of this. I went from a new parts-store 180* to a balanced 180. Nothing changed, except ambient temps increased about 2*F between data collection times (I ran the new parts store stat for one week). The balanced stat lowered my temps at idle ~8*F (it was 110* in the shade). My operating temps at speed dropped even more (but due to so many extra variables, I dont offer any numeric support).



Man, I feel for you about the wiring - on a DD! My hat's off to you! I wonder if your PO had work done by the little elves in some commercial (IIRC they use a magnifying glass to heat the asphalt under the kickstand and dump a motorcycle on its side).

I don't even have an oil pressure light on my '88 so you're doing better than me Ken. Having the light illumiate with the clutch pedal depression is scary though.

Best of luck with it all!

 

[5spd GT]

It seems in this location I can: 1. see when/if the thermostat opens, 2. I'm getting a direct temp reading of the coolant right as it comes out of the motor. That was the old thinking anyway.

Would it not be going in the motor, and not out?

Maybe I am getting confused

 

[Bottomlesspit]

Ok, just to make sure I've got this all straight....
The temp probe is located in the hole where the unfinished dimple is on the stock water neck. It starts with the engine face, then the temp probe, then the thermostat, then the water neck-tube going to the top of the radiator. The temp probe is directly next to the outlet on the motor, before the thermostat, so the probe is sitting in the coolant before the thermostat opens. Is this what we are all talking about?
I'm 5 yrs older now since I was last on here with my 93 vert, so lot's of brain cells have been used up. I could be on Mars and not realize it?! I built up a couple of Explorers in the mean time...a lot harder to work on, that's for sure!!! My 05 4x4 is with my son at college, that's now I ended up with his Mustang. I guess it's mine now, it will never make the trip to his college...way too far and unsafe.

The rear control arm bushings are so shot everytime I start or stop the pops under there scare the crap out of me. POW, POW! I still plan to slowly fix it up as time goes along, but it will never be nice like my 93 was
Thanks again guys,
Ken

 

[HISSIN50]

Ken, your stat housing must be different than mine. The 3/8" NPT boss on my housing is on the radiator-side of the t-stat.

Have you considered getting a cleaner fox (funds allowing? Tough with your son in college) and just swapping the good stuff from your existing one into it. Then you'd have a driver that's a little more tractable and you'll be able to tinker with this [existing] one and sell it for a profit.

It sucks to put more money into a car than it's worth.
Of course, there could be a sentimental attachment with this one. I know how that goes.



I can see it now: Ken is sitting at a red light next to a car full of shady characters. The light turns green and Ken is afraid to take off, fearing the characters will think he's firing off rounds at them.
Speaking of scaring ourselves: In my youth, the first time I lost a rear axle bearing I crapped myself. The wheel was locking up almost constantly as I drove - I thought the rear end was falling out of the car. Fortunately an old timer showed me how to diagnose it and I had the axle reinstalled that afternoon.

 

[SuperStang83]

Did you make sure that you had no air bubbles in the system?

 

[Bottomlesspit]

Yeah, guys...old age brain fart again. My thermostat housing is stock, with the sender towards the radiator.
I did burp the system well, or thought I did. Worth a check this weekend to make sure. Thanks for the idea!
I have thought about the idea of picking up a better condition car, but you are correct...2 kids in college...not going to happen right now. I HAVE to keep this beater running as long as possible. I know the car's value will never be worth squat without a ton of money. I am trying to do all I can to help it out. Just have to do all the work myself...piece by piece. I suppose as long as the motor keep working I will keep fixing up the rest.
Once I get the wiring under the dash finished, I have to pull the door panels and work on getting the power windows and locks to work again. It never ends?!
I sure don't want to lose an axle bearing...knock on wood.
Ken