well I'm driving to Galmis this weekend about a 3 hour drive to the desert so I decided to change the thermostat fluid and flush everything out. I got a new thermostat which now opens at 160 degrees after driving my truck doesn't get hot. it hits the line on normal doesn't hit the "n". my question it that good or bad? I have a 86 F-150 302 w/aod long bed extended cab 6"lift w 33" mud tires 174000 miles. also had some knocking problems in the mornings but when warmed up no prob, now the enging dosen't get very warm. but at high speeds no prob.

suggestions? comments? they will help before my 3 hour drive, thanks guys.

 

[updated:LAST EDITED ON 07-Jan-03 AT 04:55 PM (EST)]I put the same thermostat in my 1990 Bronco with the 351W. My engine has been bored .10 and has a few more things done to it. My engine with the original 195* thermostat ran at the "R" to "M" in NORMAL!
I think you made a great choice. I take it you live in a warm climate. If you live where it regulary gets below freezing, it might be a better idea to put back the 195*. To sum it all up I think you made a great decision!!!!! I nver regreted mine had it in for 6 months now!!!! Running great. By the way I live in Arizona!!!!!

 

The best and most efficent thermostat I have found is made by Robertshaw. They can be found at Autozone. They have higher flow charecteristics and respond faster to temp. changes. I have a 180 degree in mine, works great.

 

thanks guys i was a little worried about the change and I do live in cali, so it does get warm.

tony

 

well after talking to a few people i changed it again put in a 195. I went to auto zone bought a new thermostat and bought some coolant the stuff is orange and has a guarantee of 5 years/ 150000 miles so i bought 2 gallone about $9 bucks each. Put in a after market temp gage and the damm truck still wont heat up. drained some of the coolant and put in water and still no good. the gauge reads 140-160 when I turn it off the truck will get up to 180. @ 180 my thermostat still is not open

I can litterally open up the radiator cap while the truck is running or off after driving for hours no problem.

should I be worried about this.

ir the hose going from the top of the radiator to the thermostat to the block is hot does that mean that the thermostat is open?

I really need some help on this one guys on this friday I'm going to drive to glamis, a 3 hour drive.

tony

 

"the hose going from the top of the radiator to the thermostat to the block is hot does that mean that the thermostat is open?"

Yes. There is no coolant flow in the top radiator hose if the thermostat is shut.
What is the temperature outside where you live?
I am assuming you are letting the system settle down, and burp itself before passing judgement on it.

 

No, wrong!! The hose gets hot because there is no fluid flow! Try the other hose after your thermostat opens (the hose going to the thermostat) That hose should be pretty cool. You should have left the 160* in. It is much better for the engine to run cooler, Especiaaly when your pulling quads through the desert!!

Also sorry to burst your bubble your going to have to change the coolant again!! The orange coolant is called Dex-cool. It's made by GM and used mostly in there diesels. The problem with it is it will make brown sludge in your recovery tank,radiator and coolant passages. I ran it for a month and changed it due to the brown sludge forming. Go ahead and put the trusty grren stuff back in. Go for PEAK. It's my personal favorite!!!
HOPE THIS HELPS!!!!

 

Oh, one more tip!! If you end up fixing the thermostat at the last minut and don't have time to wait for the gasket sealer to set up at the thermostat. Let it sit for 30 minutes, then loosen the radiator cap let it get up to operating temp with out ever pressing on the gas (that creates pressure) then let it idle at oper. temp. for 10 minutes and your ready to go!!

 

Here's a couple of links for you to explore:

http://www.grapeaperacing.com/GrapeApeRacing/tech/coolingmods.cfm
http://members.tripod.com/~grannys/cooling.html

I rethought my whole opinion on thermostats after researching the subject.

 

[updated:LAST EDITED ON 10-Jan-03 AT 02:03 PM (EST)]I still stand behind my first statment about the upper radiator hose being cool till the thermostat opens. How can it be hot if there's no coolant flow in it?

"should have left the 160* in. It is much better for the engine to run cooler, Especiaaly when your pulling quads through the desert!!"

The above statement is not necessarily true in all cases. A warmer engine benefits from;

Less condensate and contaminates in the oil-these are taken away more readily by the PCV system if the engine oil is warmer.

It has been proven(not by me), that a warmer engine has less cylinder bore wear.

I also believe if a certain condition brings an engine to a certain temperature that's above the original 195 thermostat temp, that the 160 degree thermostat will not bring the temp down. In other words if you have a prolonged pulling condition in heat, and the engine runs 220 degrees, the 160 thermostat may delay that temp being reached, but given enough time, the 160 degree engine will eventually achieve the same 220. What is the difference between the 2 different thermostats if the actual running temp is above both? The are both open in this condition.

Of course if you have short periods of hard pulling, the 160 may make a difference. And it may be an option in the warmer parts of the states, but I would never run a 160 degree thermostat in a winter climate.

All I am saying is, everything is not always black and white.

 

Dex-cool is not for Fords, and cannot be mixed with the green stuff. If it is mixed, it will form a sludge that will plug up the system.
The upper hose on your truck can only get hot if the t-stat is opening. The reason for this is that the coolant leaves the engine through the t-stat, goes through the upper hose, and into the radiator. If the hose is cool when the t-stat is open, the you either have the wrong water pump on the engine, causing reverse flow, or you don't know the difference between hot and cold.
A warmer engine is a happy engine. In a cold engine, fuel is not vaporized as well, contaminants aren't burned out of the oil, and the oil doesn't protect the metal as well, causing premature wear. The only time I would run a 160* t-stat, is in a hot climate with an engine that has been overbored by .040" or more. I would recomend using a 180* t-stat, flushing the system completely with fresh water, and filling with 50/50 premix green coolant, as Ford recomends. Also, if you are going by the factory gauge, don't. They are known to be faulty. If need be, get an aftermarket gauge, but if the engine hasn't overheated on you, don't worry about it.

Jared

 

just rember to always use distiled water it will make the cooling system last much longer