Summer time heat

[Mopar1973Man]

I'm starting a general all around thread about trucks and summer heat. 

 

I know there is lots of you out there doing searching about overheating, high EGT's and other heat issues like transmission. The biggest thing to remember anything thing that is creating heat is cause by some sort of load. 

 

Engine Cooling System

 

Now how long has it been since you flushed out your cooling system? Don't buy into those coolants that claim 100k to 150k miles before failing. I would say about every 3 years tops should be flushed. Then about 70k to 80k miles in miles. Completely flush the block out with garden hose till there is no solid material or coolant color running out. Make sure to have the truck idling as well this will make sure the heater core is flushed out too. Flushing coolant and then refilling with fresh coolant reset the additive packages within the coolant. There is corrosion and lube package that get depleted. One of the few reasons I've not had any cooling problems or water pump issues. For those worried about thermostats NAPA I've been using for YEARS now and never had a bad thermostat. 

 

Transmissions (Manual / Auto both)

 

I've seen a few coming to me with transmission temps getting above 200*F. Like a friend lives near me has Chevy Duramax shift issues and higher than normal temps. He did a full pan dump and change the internal filter and all this issues went a away. Make sure you changing out your transmission fluid before the summer and installing a good filter. Clean all the coolers on the front of the radiator. 

 

Manuals for us the biggest thing to help in reduction of transmission heat is just placing a heat shield between the transmission and the exhaust pipe. This will reduce the amount of radiant heat from the pipe adding heat to the transmission. You can do this for both auto's or manuals. 

 

EGT's

 

This one could be other issues. Oversized tires, improper final ratio to the ground, excessively big injectors without enough boost to cover the fuel. Excessive weight on the truck and/or being towed. Don't be racing the truck up grade with heavy load take a minute and slow down and grab a gear lower. Climb the gear at a slower speed. Possibly with tuners improper timing for said load could also produce high EGT's. Like Edge product does not give a control for timing and typically stacking timing on top of the ECM stock timing typically this is a bit too high for towing applications. 

 

Tires and Final Ratio

 

I know there is alot of people that like the look of oversize tire and lift kits. Just remember the higher you stand in the wind the more drag comes with that lift. Just remember the drag value is based on a square foot measurement from the ground to the top of the truck and the full width. Now as for tires remember 3.55 gearing for most of the 2nd gens. Now add larger tires to that axle and your pushing that final number down so from 3.55 it will head towards 3.00:1 like 37 inch tire will do. Anything below about 3.40 it adds a lot of heat ot the engine and EGT's attempting to roll those big tire. Correct ratio makes a huge difference.  Optimal ratio is 3.55 to 3.73 final to the ground after tires have been figured in. 

[Doubletrouble]

 Great write up Mike. All good information, a diesel engine creates a lot of heat when working even if just driving an empty truck. Add a load or loaded trailer or camper and the heat builds from there. The radiators are big for a reason.

 One question, if one buys a used 2nd Gen Cummins truck (or any Gen for that matter) and finds corrosion in the cooling system when flushing such as light rust on the surfaces in the block. Is there a way to remove it? A chemical maybe that would clean that up without damaging anything else?

 I ask because I feel a clean metal surface would transfer heat better than a rusty one and once the surface rust is gone there is less chance of any small particals moving through and plugging things up or taking out the seals of the water pump.

[Mopar1973Man]

5 hours ago, Doubletrouble said:

One question, if one buys a used 2nd Gen Cummins truck (or any Gen for that matter) and finds corrosion in the cooling system when flushing such as light rust on the surfaces in the block. Is there a way to remove it?

 

Rust will be for sure in the block. Like the last time I had the head off the coolant jacket is just surface rust and meaningless. Nothing to do just leave it alone. Now if your flushing and seeing large flakes of rust you might have to discuss this with a radiator shop on different products or possibly have a shop capable of dealing with heavy rust. Scale that builds in the radiator is a sign of wasted coolant. Coolant main purpose is to correct the pH balance in the system. As the additive package is consumed now you start eating metals in the block, gaskets, etc anything that touching the corrosive coolant. This might be either direction acidic or basic. Now the oxides of metals cool at the core tubes in the radiator and deposit themselves to the metal tubes. I don't have ANY scale in my radiator even my factory radiator is perfect yet but a blown tank seal.

 

5 hours ago, Doubletrouble said:

A chemical maybe that would clean that up without damaging anything else?

There are chemicals that can eat at those materials but the problem is how strong of a chemical, how long to leave it soaking, etc. Again a professional radiator shop would know more. Personal I've never had any issues because I typically flush the coolant system by about 70k to 80k miles. If there is ANY color change of the coolant it already too late!

 

A side thing I love to do. I'll get a client that needs a radiator flush and I'll start draining the coolant they always say "See it still looks good!" I just smile and stay silent. As it comes to the last gallon and coolant start to change to rusty color I now speak up and say"Nope. The rust just proves the additive package was gone". Then typically I look in the tanks of the radiator and you'll find starts of scale blooms. The owner is now speechless and like the last one said it was factory coolant and nothing ever been added. Just because its factory coolant doesn't mean the additives will last forever. 

 

Another side note. I've been doing my own testing. Now I've been doing my coolant system flushes with creek water or well water. Never used any distilled water in 431k miles. The block is still clean inside, light surface rust that is all. ZERO scale blooms in the radiator. Both waters I use is very clean and clear and drinkable. Very low mineral content. 

 

Water pump... Hmmm... I'm still running factory OEM water pump. I've never changed a water pump yet on my truck. Again I keep good coolant in the system so there is lubricant package for that too. Again wasted coolant will no longer be able to keep water pumps lubed so the shaft seal fails and now you see the weep hole bleeding coolant. 

Edited July 16, 2021 by Mopar1973Man

[Silverwolf2691]

On 7/16/2021 at 10:16 AM, Mopar1973Man said:

Tires and Final Ratio

 

I know there is alot of people that like the look of oversize tire and lift kits. Just remember the higher you stand in the wind the more drag comes with that lift. Just remember the drag value is based on a square foot measurement from the ground to the top of the truck and the full width. Now as for tires remember 3.55 gearing for most of the 2nd gens. Now add larger tires to that axle and your pushing that final number down so from 3.55 it will head towards 3.00:1 like 37 inch tire will do. Anything below about 3.40 it adds a lot of heat ot the engine and EGT's attempting to roll those big tire. Correct ratio makes a huge difference.  Optimal ratio is 3.55 to 3.73 final to the ground after tires have been figured in. 

 

What about those of us odd balls with 4.10s?

[Mopar1973Man]

4.10 gears are the ticket for 35 to 37 inch tires.

[JAG1]

Around Portland, Oregon the latest fad is the super extra wide tires, not tall, with extra deep rims. Look like big toilet paper rolls way beyond the fenders on there. No mud flaps either. I wonder what they're smokin? 

[Silverwolf2691]

31s/33s on 20s or larger. Oh and 12.5 inch wide tires on 14 to 15 inch rims.. 

 

 

Almost always paired with a lower lift.. if any

 

It looks wrong, like the trucks skipped leg day at the gym..

[IBMobile]

3 hours ago, JAG1 said:

I wonder what they're smokin? 

Better stuff than you were in the 60's. 

[Dieselfuture]

3 hours ago, JAG1 said:

I wonder what they're smokin? 

New generation is retarded simply put. I fear that movie Idiocracy will soon be reality. 

[Royal Squire]

My son has a friend that has those real wide tires. They measured and his overall width is 12 feet!!

[JAG1]

I like moparMan style.... pizza cutters, lawn chairs and beer.

3 hours ago, Silverwolf2691 said:

31s/33s on 20s or larger. Oh and 12.5 inch wide tires on 14 to 15 inch rims.. 

 

 

Almost always paired with a lower lift.. if any

 

It looks wrong, like the trucks skipped leg day at the gym..

[Mopar1973Man]

I always love the guys with the desire to have 35 to 37 inch tires without any planning. When I do find them I always challenge for race and typically win. What good is it to go to the gym for leg day if your shoes are both tied together at the track? You still lose the race. When I might have a mere 30 inch tire (3.69:1 ratio) but product more power and torque to the ground that anyone with 35 to 37 inch tires with 3.55 gears which is 3.00:1 final ratio for 37 inch tire. 

 

Then flip it the other way those same guys with 35 to 37 inch tires will be parking there trucks because low teens MPG. (12 to 14 MPG) and the price of diesel heading past 4.00 a gallon. McCall ID is 4.109 a gallon today at Maverik. I'll go back to hypermiling and still twist out 20 plus MPG. Physics simply states you can add more spinning mass and gain power and torque. The bigger mass spinning on the axles will take a percentage of power and turn it into heat. (axle oil, tires, etc.). Since I don't have all the spinning mass I gain more for the power output and the MPG's too!

 

I'm like that skinny buff fighter that just beats everyone. David and Goliath who took down the giant with a slingshot. Hmmm...  

Edited July 20, 2021 by Mopar1973Man

[Silverwolf2691]

I'm never afraid of the boastful built guy, I'm afraid of the skinny quiet guy. I have a small skinny friend who I wouldn't trade for anything in a fight.

 

The built quiet guy however, make sure he's on your team.

 

*I don't condone fighting, but I've been around enough that some people just have an axe to grind that day. 

[JAG1]

On 7/20/2021 at 6:23 AM, Mopar1973Man said:

I always love the guys with the desire to have 35 to 37 inch tires without any planning. When I do find them I always challenge for race and typically win. What good is it to go to the gym for leg day if your shoes are both tied together at the track? You still lose the race. When I might have a mere 30 inch tire (3.69:1 ratio) but product more power and torque to the ground that anyone with 35 to 37 inch tires with 3.55 gears which is 3.00:1 final ratio for 37 inch tire. 

 

Then flip it the other way those same guys with 35 to 37 inch tires will be parking there trucks because low teens MPG. (12 to 14 MPG) and the price of diesel heading past 4.00 a gallon. McCall ID is 4.109 a gallon today at Maverik. I'll go back to hypermiling and still twist out 20 plus MPG. Physics simply states you can add more spinning mass and gain power and torque. The bigger mass spinning on the axles will take a percentage of power and turn it into heat. (axle oil, tires, etc.). Since I don't have all the spinning mass I gain more for the power output and the MPG's too!

 

I'm like that skinny buff fighter that just beats everyone. David and Goliath who took down the giant with a slingshot. Hmmm...  

Get those free wheel spin hubs for sale on the site,  get us all a good deal and watch the MPG savings roll. Dynatrac is one comes to mind.

 

If you ever get a chance to figure how much money you save with even just a 2 mile per gallon increase..... its incredible how it adds up to a lot.

Edited July 22, 2021 by JAG1

[Silverwolf2691]

Spyntec shorty with Dynatrac Dynalocs is supposedly the shortest combo for free spins. Its just hard to cough up the $2500+ for the kit and hubs. is there much of a benefit for the CAD axle trucks? I can see for @Mopar1973Man's truck being non-CAD, but I thought the whole point of the "automatic" hubs was to do away with the manual hubs.. 

[AH64ID]

I ran a Yukon spin-free kit on my 05 and can honestly say I never saw any definitive increase in fuel economy from it. It did make a huge difference in steering wheel feel, and 2LO was nice but I am not repeating that mod on my 18. Sure I wanted to, but it just wasn't something I could say gave me a benefit. 

 

Dad also put them on his 2006 and never saw any mpg increase either. 

 

There are advantages and disadvantages to the narrower shorty kits. I chose Yukon since it ran the old school wide stance for a couple reasons. The wider stance puts less stress on the bearings in turns and also run cooler. 

Edited July 22, 2021 by AH64ID

[Mopar1973Man]

Never thought there would be any savings between free spin hub for the price.

[JAG1]

I read there is about a 2 MPG increase so the calculations on my desk said it was a good deal and paid for itself in about 1.5 years. Then add easy bearing rebuilds with standard bearings, no more hubs. There are many times I could use low range on hard pavement without the 4 wd.

 

 

Working in a well to do neighborhood one month, other contractors working different homes up and down the same street. Many of their trucks had the 37's, some would snicker at my stock size going by. I could see that LOL but, one of them stopped me one day and said, ''Are you a woman, Why do you have such small tires on your truck?". I said because it's easier to work from a truck that's not jacked up, plus I am a contrarian, buck the trend, and go easy on my running gear without putting added leverage against the transmission and other parts. He says, Oh, okay and I drive onto my destination. 

Edited July 30, 2021 by JAG1

[Silverwolf2691]

4 hours ago, JAG1 said:

There are many times I could use low range on hard pavement without the 4 wd

 

If you have a cad axle, you could just pull the vacuum connector off the actuator. Did that once or twice to drive in a holiday light show parade in a park. Had about 10 people in the bed with blankets and pillows. 2lo and 2nd or third, dont remember, was the right amount of take off ease on the clutch and slow speed creeping to keep up with the line. I think that's pretty much all the pacbrake or bd 2lo kits are.. Just a spool valve to stop the vacuum from actuating the disconnect. I think for the 02 and up trucks with no cad its a transfer case rooster comb change, unless its only for the np231s...  [quick internet search says free spins only from 2002 to 2009. After 2009 they started bringing the cad back into the trucks, just electronically. I'm curious if you could do a rooster comb modification to the 241 to do the same thing as the np231. I know the shifting pattern is different, why? No idea.]

Edited July 30, 2021 by Silverwolf2691

[IBMobile]

@wil440 installed a vacuum control switch in his so he could use 4 LO with the front axle free.