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I have a 180 thermostat on my 93' f-150 5.8L with no power modifications except for an all accel ignition. I don't have any issues with driveability as is and all systems are normal. I was wondering if a 180 thermostat even be necassary, because i'm curious as to wheter or not if the 180 would make the truck run rich.
I would have to say yes it does make it run rich. I tried a 180 in my truck and it got worse fuel economy and also failed sniffer test because of it. I have a 190-195 now. I think its 195. Thats the operating temp it is set up for.
I ran a 180 for several years before switching to a stock 192. I didn't notice any difference in fuel mileage between the two. All the warm up enrichment should be phased out by the time the engine reaches somewhere around 170, so there shouldn't be much difference. You could always switch thermostats and see if it makes any difference.
Uhm yeah, I changed the 180 thermostat to oem thermostat and truck is running very close to hot. The needle points to around the A and L in NORMAL. Just curious, where should the needle point to with the oem thermostat? I've already replaced the temp sending unit and checked the gauge, it's fine. The antifreeze solution is appropriate at 50/50 and I have no leaks. I am going to check the radiator cap. I've felt the fan clutch and it turns with some resistance. I know it could be a clogged radiator or engine block but what else could overheating be caused by?
Last edited by rusilva; May 19, 2009 at 11:39 PM.
Reason: left out info
My carbed '85 used to do the same thing when I ran the stock 192 degree thermostat. The needle would always point around the "A" and "L" on the "NORMAL" gauge. When it got really hot and humid here, it would come way too close to the red line for me. I never could figure out why, when other trucks ran the same thermostat and hovered around the middle of the gauge. I tested and tried two different thermostats and the same thing happened.
Finally, I reluctantly went to a 180 degree thermostat, and it solved the problem. Now it consistently reads between the "O" and "R." And I still don't know why. I wouldn't go below a 180 though.
The factory temp gauges are useless.. they do not display a real temperature so there's no way to know what temp the motor is actually running at. I have tried several sending units in my truck and each one produces a different output on the gauge.. with no other engine changes. I suggest you get a real temp gauge to see if you actually have an overheating problem or not.
Conanski, you are correct about the different sending units giving different measurements.
My oil sending unit was bad when I got my truck. I replaced it with one from NAPA, and it never got above 1/4" on the scale, and sometimes lower. I got a brand new one from NAPA again, and got the same reading. I went through a lot of trouble checking the oil pump, pickup screen, etc. before finding out everything was ok. I went to FORD and bought a Motorcraft oil sending unit, and my gauge shot all the way across the gauge to the 3/4" mark at startup. This is where I have seen it rest on newer trucks.
I replaced my temperature gauge with a Motorcraft unit, and a Motorcraft thermostat, and I found I still needed a 180 degree thermostat. Brand new radiator, heater core, hoses, and water pump too.
After doing some engine modifications recently, I discovered that the 302 engine has a 0.060 overbore! (Thanks for the cam and heads advice, Conanski, BIG improvement over stock!) Maybe that has something to do with it, I don't know, but the 180 degree works good so far.
A motor with a cam in it does run a bit hotter, I have noticed this with both my 5.0 and 5.8 motors, so it's entirely possible a motor like this with a 180deg stat will still run about 190deg or so which keeps the EFI system in closed loop.
So Conanski,
What would be a good running temp for the motors? I have a aftermarket gauge on mine but no one has been able to tell me a good temp for the motor.
I currently have a 195 stat and the temp reads 210. With or without the AC on, towing the boat or not... It is always at 210.
My fear is that that gives me very little room for the motor to heat up when working harder pulling the bigger camper over hills... What do you think? Drop to a 180?
Just a question to add to this conversation... If I'm going to use an aftermarket temperature gauge, do I need to change the sending unit or do I just plug it in to the regular one on the engine?
I changed my sending unit as the new gauge came with it. I figure better to use the one they sent with it then something that might not ohm out correct.
I changed my sending unit as the new gauge came with it. I figure better to use the one they sent with it then something that might not ohm out correct.
John
Good point. I didn't realize they come with one, unless some don't.