Ok so I have stated my thoughts on this before but I would like to revisit the issue. We all know that diesel engine like heat and in the winter that can be interesting. I have seen many posts about cold fronts (vinyl, cardboard, Plexiglas) to cover the radiator to get more heat in the engine and cab. This seems to me, to go against the design of the cooling system.

The Thermostat (if its working correctly) will stay closed (no coolant flow to the radiator) up to a certain tempature. Most of our trucks either have a 195° or 203°. So the stat should keep engine temps close to those numbers if they are working correctly. If the engine coolant goes above that the stat opens and allows coolant to the radiator where is cooled and sent back to the engine. The heater core gets coolant straight from the passenger side head and in theory the coolant should be a pretty uniform tempature.

I have also seen many claim faster warm up times with the radiator covered but again since no coolant should be flowing in the radiator I don't see how that is possible.

So in my mind I can't see how adding an air diverter to the radiator on a properly working system should do any good.

Lets discuss how this works, what you have seen by adding one of these devices or not having one. What thermostat do you run and what is your average coolant temp? For those of with the stock gauge your letters (N O R M A L)will be hard to quantify but still somewhat helpful.

I know that OTR trucks use these but they are different animals so unless you have input (facts) on why they run them they are not part of the this conversation.

I will start with what I see in my truck. Mod in the sig running a IC, 203 stat and as of right now no fan just cuase I didn't want to put it back on after my last WP R+R. Does not matter though cause no change in temps with or without it. Aftermarket temp gauge with the sender located right under the thermostat in the WP in an empty fitting. Summer and winter normal driving I run a solid steady 200-205. If I am running really hard (towing with a heavy foot or doing 1/4 mile passes on back roads) it will creep up toward 210. Winter temps make no difference. single digits to zero no matter. Cab heat is hot. I have to run the temp selector at the very middle of cold and hot to not roast myself out.

So since all of our cooling systems are equal I don't see why some of you need your radiator covered to get good heat in the cab and temps in the engine.

Help me understand.....
(please don't hijack this thread with repair questions about your truck or bunny trails about OT matters!) I will do my best to abide by my own request

 

tim, i agree 100%. last year i used plexiglass to cover my radiator to try and get my temps back up, i cant comment on actual values since i run a stock gauge but the gauge does drop in the winter time a considerable amount. running the plexiglass cover made no difference at all, my truck has good heat, i wouldnt say it burns you out of the cab but it is hot. after running for a while i turn it back to about 3/4 heat and move the selector to the floor. running uncovered my warmup time is about 1-2 miles of 25-30mph cruising from my house. if it gets in the single digits its more along the lines of 4-5 miles to get hot heat.
this is also using no block heater or idle time, thats fire up and take off. if temps reach single digits or negatives i have to idle for about 45 seconds to a minute since i run 1540 year round. if i try to take off in extreme cold i have no throttle response.
i will check to see if i have a spare temp gauge laying around and perhaps i will install it if i have one to play the game.

 

So Joe you see a temp drop but covering the radiator did not help? That doesn't make much sense either. What does your EOT run when warmed up? I sit right about 180-185 in the winter 190 in the summer (I Think)

 

i would have to get ahold of the scanner again, if i gave you a number right now it would be a pure guess. i'll get the ngs and remove the eot mod and get some numbers for wintertime anyway.

your 180-185 numbers, is that at cruise or is that at idle? i cant quote you numbers but i do know that my eot will drop at idle considerably in the wintertime. once i get cruising under a load it will heat up. i do recall that before the eot mod went in that i could not get above 170 at idle during the winter. iwant to say 155-160 but dont hold me to that. to perform a cct test i had to run the crap out of the truck and pull over realy quick and run the test to keep the eot up long enough to run the test.

 

All my temps are cruise numbers. All bets are off with long idles times and temps!

 

i dont have to idle for more then a few minutes and i am below 170, i will try to get ahold of the ngs tomarrow if possible, then i will have actual numbers to play with

 

The T-stat is more like a throttle valve.
No 2 T-stats are the same. Even from the same lot.
Lets use the 195*. The 195* may start to open on/about +/-% "195*".
This 195* might be full open by 210* on/about +/-%.
Its the same on the other end of the spectrum. Using the same #s (15*)
the T-stat will not fully close until 170* after the first cycle of the T-stat opening. First opening from fully closed was 195*.
Winter fronts warm the whole system. No air crossing the core allows it
to hold more heat. The PSD is very efficient. Most of the energy produced
is not converted into heat.
Most run the coolant temp sensor at the T-stat.
Test have shown gauge and stat looks good.
Now take the sensor and move it to the center of the head.
My sensor is in the center of the drivers side head by the exhaust port.
Gauge at that location shows a much longer time to reach opt temp,
or match the t-stat. It somewhat mimics the oil temp (rate to rise).
My coolant system is a bit more balanced do to i have a heater plumbed on the divers head. Its just like the cab heater on pass head.
So flow should be about the same.

Tj BTW the EBPV sol trick worked! Limping home.

Bill

 

I used to cover my radiator as well. I didn't do it this year because the only time I drive my stroker is for trips and on the weekends.

During the summer time my truck's operating temperature varies between 215 and 205. It's always been like this and I'm not sure why it's higher than most. I usually intsall my fan back on somtime in late April.

I remove the fan during the winter because I want better throttle response and I with the sub zereo temperatures in Iowa the truck cools itself rather well. On the normal day, operating temperature usually stay around 205. About 10 degrees cooler than the summertime. When the temps where down to about -27 plus windchill, my rig would barely hit 165 until I pulled on the super slate. Even then, it still barely hit 200 at 75 mph.

I've noticed that with the radiator covered up, it retains the heat better when not traveling on the highway. For example, slowing down or driving in the town. Adding a winter front only seems to reduce the variability in temperatures during different operating patterns.

I have to agree with you TJ on this aswell. Blocking the air flow to the radiater would only help if you have a stuck thermostat.

 

Not sure if anything I know about this topic is worth reading but back when we had a fleet of OBS trucks at work we had winter fronts on all the diesels because of complaints with cab heating and the darned EBPV coming on all the time. One thing that you are missing TJ is that cold air (especialy when darned cold) flowing around the motor cools too and the winter fronts stop part of it. My current truck has a new 'stat from Ford. I have no idea what temp, long or short. I bought it and put it in before I knew about things like 203s. A couple weeks ago I drovethe truck 15 miles to a buddy's place who has a scanner. I let it warm up for 15 minutes before the trip and although the heater was putting out decent heat the coolant temps were too cold to run a contribution test and he had to shut the heater off to get it warm enough for the test to start. As I remember it was like 10 degrees that day. Mine sits most of the winter so these cold weather issues are kinda OT for me, LOL

 

Farm

Wind chil will just drop the coolant temp to ambient temp quicker.
It becomes more efficient (rad). You cannot cool it down to wind chil
temp.

Bill

 

-27 was the ambient temperature that morning. IIRC wind chill was around -45 that day.

 

dats COLD!! My whole truck would need a blanket then!

 

forget the truck, where's my blanky!!!!

 

Yeah, that morning broke all the records. The one thing that really surprised me was the amount of drag the differentials had. Wow. I actually had to give it fuel to move the truck! I did the "throw a cup of water into the air" trick and bam it would disappear in a white cloud before it hit the ground.

But anyways, it wouldn't get to operating temp that day at all. About 20 miles down the interstate it finally made it to 195.

 

Just the sound of that temp hurts.

Bill