Cannot Get Truck to Run Hot...

I don't understand what the problem is.

Greetings,

It sounds like your truck is near enough OK, but I've seen these symptoms happen with a combination of three things: Running a "Heavy Duty" or "High Flow" thermostat, air in your system, and having a worn out radiator cap.

Use a cheap, normal flow thermostat, buy a new radiator cap, and find the nipple that lets you bleed out any trapped air in your cooling system (usually on or near the thermostat housing).

Cheers - Jonathan

the truck runs at 165 even though it has a 195 thermostat in it.

I had this with two Rangers. Cooling system working fine, cold weather hits and the only way it gets good and warm is to put cardboard in front of half of the radiator.

I have a 1994 Silverado,5.7 Long Bed.I have a 195 thermostat.When the weather is cold,averaging 10 to 20m degrees at night,I have low heat temps too.I added 1/2 sheet of heavy cardboard in front of radiator.It helps.Make sure it is not too big and covers too much of the radiator.It can get too hot.

Burp your cooling system... It has air in it...

eventually could not

help me out.

196, then drops

probably the best to do is put some cardboard over the front I put 3 pieces on it that way if it excessively cold like below 20 I can cover the whole radiator to get it warmed up faster and then adjust the coverage by moving the center off to the side until needed again a very old trick but works great . Now if you have to ask about burping the coolant system then you may not want to attempt this and the best thing to do is take it to a reputable garage and have them do it for you this way it will be done right and if there is something else that comes up they will know what to do or let you decide how you want to handle it . The biggest problem today is the coolant systems are the most efficient ones that has ever been made but the problem that comes from cooler regions is they are the most efficient cooling systems that ever has been made and have to make some kind of compensation considering the wind chill in the winter where a still air at 32 degrees will drop to 15 degrees going at about 45 - 50 mph . so good luck and report back to what you find out what the problem is

If you have to put a piece of cardboard in front of your radiator something is wrong with your cooling system. The thermostat should open and close to maintain the rated temp of the stat.

Wind-chill does not affect cars or trucks. Still air at 32 degrees has the same effect on a vehicle as 32 degree air at 45-50 MPH. A common misconception. Regards, JR

When you replaced the heater hose quick connect, did you replace it with the correct replacement part or did you put in a plain hose barb?

Greetings,

Depending on your set up there is usually a small screw plug in the thermostat housing at the highest point in your cooling system. Remove the plug with the motor cold, start it up and let it get hot. When your thermostat opens up and fluid starts to flow from the hole then you can replace the plug. You could also speed up the process by squeezing the upper hose a few times with the plug out to help move the air out.

If you don't have a bleed plug, then you can try a few basic tricks. With the motor cold, remove the radiator cap and squeeze the upper radiator hose several times. You should be able to hear/feel the air in the line and watch inside the mouth to see when it gets pushed into the radiator. Fill the radiator to the top and replace the cap. You may need to remove the cap and start the truck and let it warm up until your thermostat opens to get the air out, or as a last resort loosen the highest clamp on the upper radiator hose to bleed it.

Always remember to keep the overflow tank full and check the lines to it for leaks. A cracked line or leaky fitting to the neck of the radiator is a typical place for air to get into the system when the motor cools off and fluid gets pulled back into the radiator from the overflow tank.

Cheers - Jonathan

what ? the radiator is a cooling system not a heating system ,and wind chill have nothing to do with anything hmm have you ever drive in cold weather or do you keep your vehicle in a garage most of the time ,around here we can get temperatures as low as below zero in the winter and as high as 100 during the summer and when a vehicle drops down that low I have literally seen the temperature gauge drop while going down the road by why because the radiator is very efficient thats fine in summer but in winter it is a pain since the radiator will let go of the heat to the surrounding air as fast as the surrounding air will take it the colder the air the more heat it will absorb ,a good example is the fact when a car has a bad electric fan during the summer if you stay still the temperature goes up but once you get moving the temperature goes down ,because air is moving thru the radiator and absorbing the heat and leaving the radiator surface at a cooler temperature ,thats what fans do to create airflow so that the radiator can exchange the heat to the air at a more efficient rate ,now they are designed in an average temperature range of 25-95 degrees to work properly now what happens when the temperature drops to below

20 degrees now that radiator is exchanging the heat to the air at faster rate faster than it was designed for the coolant now is not getting to the point to keep the heater working properly because the coolant is not as warm as it should be due to it's efficient heat transfer ,so how do you change the heat exchange rate ,you restrict air from moving across the cooling surface which you do by placing something over part of the surface to create in simple terms a smaller radiator which keeps the heat from being exchanged into the air as fast . now someone will ask then why in the summer does the radiator overheat well humidity plays an important role in the heat exchange as well ,even in colder weather here we have humidity which is moisture and is a great sponge for absorbing heat but like a sponge it can only hold so much ,the colder the moisture the more heat it can hold and the warmer the moisture the less heat it can hold so during the winter it can hold quite alot but in the summer it already is partly full of heat so it can't hold as much so it becomes less efficient which is why the fan runs all the time to compensate for the decrease in the heat exchange rate is to run more air thru it or use alot more half filled sponges . basically three things control the efficiency of your coolant system and heater system, air temperature , humidity in the air,and amount of airflow and out of those three the only one you can control is the airflow ,I hope this has been informing if not whatever .

Coolant flow thru the system has the greatest effect on engine temp. The cooling system is designed to hold coolant in the engine block until the thermostat starts to open. If the coolant cools down far enough the thermostat starts to close holding the coolant in the engine block to absorb heat, thus heating the thermostat enough to cause it to open. The thermostat doesn't care what the temp is in the radiator. Regards, JR

The radiator is what actually controls the temperature along with the fan ,you can run the engine without the thermostat it just takes it longer to warm up since it is running thru the radiator already but I would like to see a liquid cool engine run without a radiator ,all engines have some sort of cooling system whether it is a radiator or on aircooled engines it is the fins directly around the cylinders themselves,you can run an engine without a thermostat just not advised to do it outside of an emergency situation and only til the thermostat is bought and actually I guess you have never driven in the southwest in the summer stop your car with the engine running and you can watch the temperture rise even tho the coolant system is working perfectly ,the reason for this is that the air has so little moisture that the heat is not transferring to the air very well but when you get moving it will cool back down because you are increasing the flow of cooler air thru the radiator and transfer more heat just not as efficient because of the low moisture level and the warmer air,thats why years ago some vehicles got larger radiators installed in them to help compensate for the atmospheric conditions

This is getting really tiring but I will say it once again. The radiator cools the coolant, period. How well it cools depends on several factors, mostly airflow thru it. The thermostat controls the temp of the coolant in the engine block. The thermostat does not care how well the radiator does it's job as long as the coolant temp is lower than the thermostat rating when the coolant returns to the engine. The OP needs to buy a good name brand Thermostat (Stant) and radiator cap (Stant) and install them properly and make sure he has the proper level of coolant in the radiator. I'm betting his problems will go away.

The Only time I have ever put cardboard in front of my radiator was back when I was in college and the thermostat stuck open in my '65 Ford Falcon 200c.i.d. straight 6 cyl. I used the cardboard for 2-3 days until I could get home and change out the failed thermostat.

And BTW I have run more than a few engines on the engine stand without radiators using a raw water source to the inlet of the pump and a drain line from the water outlet. The THERMOSTAT blocked the water flow until the engine came up to temp then opened and allowed the HOT water to exit the engine block and out the drain. The THERMOSTAT then regulated the temp of the water in the engine at the PROPER temp range by opening and closing slightly.

I would LOVE to see you run a water cooled engine at the PROPER temp under varying conditions without a thermostat. Even outboard boat motors have thermostats. Regard, JR

I'll try to explain this too you again the radiator regulates the temperature all the thermostat does is restricts the coolant to warm up faster then opens radiator can do its job and regulate the temperature ,and you can run an engine without a thermostat ,instead of 3 minutes to start warming up it takes 10 minutes and it ran just the same no difference ,and my uncle had a couple old surplus power wagens that he ran without the thermostats for literally years ,and since your such an expert where is the thermostat on any motorcycles aircooled engines ? Then maybe you can explain why drag cars and stock cars and trucks dont run thermostats ? Thermostat is just there to get the heater working sooner ,just a convenience mostly. Ok now heres a real good guestion for you why does a car that can sit in PA running for hours on end in the summer not overheat but take same car to Reno Nevada at the same temperature and it overheats from just sitting at a red light ? This is actual experience now talking ,know why ? air is too dry . One more thing you better tell every truck driver out there on the road in the middle of winter that they don't know what they are doing when they put cardboard in the front of their radiator or why they sell grill covers and why some models actually come with the grill designed to be like shutters to shut them close when needed,those trucks cost more than your home and an average tire repair bill can be 150-200 at a shot easily ,and their engines run 24 hours a day ,but your right they don't know what they are doing.