View Full Version : 195 Degree Thermostat???

08-08-2003, 02:51 AM
195' ??
Does this seem strange to anyone?
I always thought 180 was the norm.

Mechanic at part store said if I put a lower temp thermo in that it may confuse the puter. Thus making the puter richen up the fuel mixture causing other problems. Is this correct? My Bird has been running SO hot since I put my K&N on, and thought I'd try a new thermostat.

MIKE 38sc
08-08-2003, 02:54 AM
No Bob not strange at all, Thats the stocker. Thats the one I use.
Yeah what the guy told you is basicaly correct!

08-08-2003, 03:10 AM
OK, Thanks Mike!
Just sounded odd. Maybe I'll try some water wetter if new thermo doesn't help.

MIKE 38sc
08-08-2003, 03:23 AM
How hot you runin Bob?
What did you do with the air filter to cause engine temp to rise?

08-08-2003, 03:38 AM
Yes, the parts guy was almost right. The cooler t-stat will slightly affect te computer and cause the engine to run slightly richer, but also cooler which helps keep detonation away, and also means a denser aircharge(slightly) because the engine itself is cooler, the intake temps will be cooler as well. I wouldn't say it woudl cause problems other than a slight decrease in gas mileage. On thw Water Wetter, I would put it in the same time you do the t-stat. It definitly helps as long as you are getting good airflow across the radiator. Also, you might try a coolant system flush and a new ater pump.

MIKE 38sc
08-08-2003, 04:10 AM
Problem with 180 thermostat in these cars is it really doesnt make the engine run any cooler. The radiator is just too small on this car. Theres not enough extra capacity to help make up for a dirty radiator or a radiator that might be having small problems.
The stock system must be in perfect condition at all times or it just cant handle it well. That makes it easier to hurt the engine by running too hot, But 195 isnt too hot for an engine.
The trick is running 195 reliably and you just cant do it with the stock system if you dont keep it 100% in working order all the time.
Put some insurance in there, buy a bigger radiator. That will solve your problem. A thermostat will not.
A richer running engine does run cooler, but that engine is also more slugish and loses a little throttle response as well.
Running 195 and at proper fuel mixture will run better than running 180 and rich mixtures.

08-08-2003, 04:28 AM
Yes, don't expect the cooler t-stat to keep the car cooler. If you are having overheating problems, then you need to find the cause of that. The only way a t-stat can stop overheating is if the one in the car now is bad. I think the stock system works fairly well. I've only had my car for a few weeks, but in that time it has seen 100+ temps while driving and it never overheated. I do have a 180-t-stst in the car, 130K miles and stock head gaskets. During the day when it's hot out, the temp guage hangs out around the "r" in norm. At night when it's cool outside, it's well below the "N" on norm. A better radiator will definitly help keep it the same temp all the time though, but a boosted motor will usually always run hotter than a N/A motor.

MIKE 38sc
08-08-2003, 04:40 AM
Sure a boosted car does have the ability to heat up quicker, but really unless you are hammering it for long periods of time it shouldnt heat up like it does. You know, just driving around normal on a hot day shouldnt make the car run hot but far too often it does. None of my other boosted cars ever did this and they had hot turbos to cool off as well. You dont have that with this engine. It should run cooler ie more stabalized.

08-08-2003, 08:12 AM
I've tried many things to cool my 93 sc down; a 180 thermostat, red line, and total flush, and found no relief. My next move will be to install a new radiator over the winter. A 3.8 sc radiator takes 11.9 qts of coolant. How much more coolant will an upgrade take, and where is the best place to get one.

08-08-2003, 12:35 PM
I always wonder what "cool it down" means when talking about these cars. 220f is a normal operating temp for our cars yet I think sometimes people thing that is too high.

MIKE 38sc
08-08-2003, 01:19 PM
Mike 220 might be considered normal by some people, but its anything but normal, at 220 youre much too close to the boiling point of water for that temp to be accepted as normal. The engine doesnt like 220 I asure you. Too many other things going on at 220 for it to be good for the engine or performance. Getting it below 200 and keeping it there will reward you with better performance and increase the life of your engine. The problem is easy to take care. Put a bigger radiator on the car. Very simple actualy. Doesnt have to cost an arm and a leg to do it either.

08-08-2003, 08:45 PM
one other item that will help is having the fan turn on at a lower temp either by a chip or a fan control switch, or just to an on/off switch and control it yourself. Your really not doing a lot of good if you do put in a lower t-stat but leave the fan turning on at a higher temp.

08-08-2003, 09:03 PM
Im running at 190 is that to low?

MIKE 38sc
08-08-2003, 10:14 PM
lessonintorque: No, youre fine!

SCme: Yeah that little trick will help, but its still a stop gap measure at best.
Get the car running cool the normal way like it should be without any of that other stuff and you wont have anything to worry about again, that is until the water pump goes or you blow a hose. The car should cool itself just like any other normal engine...period.

08-09-2003, 02:28 AM
on my 89 looking at the fuel tables in the ecm they look the same for130,160, 180 and 195 it goes by rpm more than temp , i use a 180 it runs cooler for me ,on a hot day if im in town sitting at lots of red lights it runs up to 228 until fan kicks on , the 02 sensor starts working after about 1 to 3 minutes after starting car this controls your mixture from the fuel tables in the ecm , if you want to save fuel mine goes in to open loop just over 4 pounds of boost keep it at 4 pounds or below boost to stay in closed loop ,
the injecter pulse width gets shorter when coolant is over 200 degrees is the only diff i can see

CRANK_FUEL_PULSEWIDTH_VS_ECT # Crank Fuel pulsewidth vs ECT (ECT, PW in secs)
( 65534, 0.0108032 ) ( 250, 0.0108032 ) ( 200, 0.0114746 )
( 90, 0.0137634 ) ( 70, 0.0218811 ) ( 40, 0.0387573 )
( 0, 0.0780029 ) ( -20, 0.095993 ) ( -65536, 0.095993 )
( 7934, 0.0605469 ) ( 7936, 0.0605469 )

BASE_FUEL_TABLE # Base Fuel Table (A/F ratio)(Load vs rpm)

500 rpm 750 rpm 1000 rpm 1250rpm 1500 rpm 1750 rpm 2000 rpm 3000 rpm 4000rpm 5000rpm

13.9537 13.9537 13.9537 14.64 15.3262 15.3262 15.3262 14.64 14.64 14.64
13.1531 13.1531 13.1531 13.6106 14.1825 14.1825 14.1825 14.64 14.64 14.64
13.1531 13.1531 13.1531 13.6106 14.1825 14.1825 14.1825 14.64 14.64 14.64
12.4669 12.4669 12.4669 13.1531 14.0681 14.0681 14.1825 14.64 14.64 14.64
10.98 11.0944 11.6662 12.3525 13.9537 13.9537 13.9537 13.9537 13.9537 13.9537
10.5225 10.5225 10.5225 11.6662 11.6662 11.6662 11.6662 11.6662 11.6662 11.6662
9.95062 9.95062 9.95062 9.95062 10.98 10.98 10.98 10.98 10.98 10.98
9.95062 9.95062 9.95062 10.98 10.98 10.98 10.98 10.98 10.98 10.98

08-09-2003, 09:43 AM
Mike 38SC you are correct about making sure the actual system is up to par, but IMO the stock fan temp turn on points is just too high. If someones car is running hot all the time, best time/money is spent looking for the main problem and correcting that and then doing the other items as added prevention.

MIKE 38sc
08-09-2003, 02:19 PM
Oh I agree and the main culprit is that cheesyassed radiator Ford put in this car. Its just too small. You fix that problem and the stock fan turn on and off points would be just fine.
Like I said put a big radiator on it and everything else will be fine.
My God I have 4 cylinder cars with bigger radiators(stock) than this thing and those engines have a turbo on them and they NEVER get hot. Every engine I have has a 190-195 thermostat in it and they have always run just FINE with no overheating.
This engine should be no different, its just that the radiator is so small its right on the ragged edge of being too small to begin with so theres absoulutely no extra capacity built into it incase you have a small cooling system problem or you live in an area that has HIGH humidity like you do. High humidity seriously reduces the ability for the radiator to transfer the heat out of the radiator. Every problem with the stock system is a BIG problem because of the tiny radiator.
Put a big radiator on the car and be done with it. No need to tweak the comp for different turn on and off points. That doesnt address the real problem.:)