Cleaning Radiator

[spike45]

Originally Posted by dball

Well, I did my radiator cleaning today. Again, I could do nothing effectively from the engine side. I used Simple Green and got lots of black material even during the application. I used a power washer (had NO problems with fin damage) and got loads of black drainage so I think I did some good. However, I still see very little light through the radiator when I place a drop light on the engine side. I have no experience with this so I don't know what I am supposed to see. It will be two more weeks before I take it back to the mountains. This time it will be the Smokies and not the Rockies. That won't be as challenging so I still don't think I will know if I really solved my problem. Somewhere I read that there should be a 20 degree temp drop across the radiator if it is doing the job of cooling adequately. Can anybody comment?
dball

As a former Caterpillar certified truck engine training instructor, I taught courses on troubleshooting engine cooling systems problems. A publication of that era (1980s), "Know Your Cooling System" states that with the thermostats fully open meaning the engine is under loaded conditions sufficient cause this, the temperature drop across the core ranges from 7 - 15 degrees Fahrenheit. The range can is due to atmospheric density, fan speeds, and ambient air temperature. It is a 7 degree drop across the core in higher altitudes due to reduced air pressure thus less cooling medium.

Be certain that you are using a pressure cap rating recommended by Caterpillar, not your motor home manufacturer. Higher cap pressures increase coolant boiling temperatures which will cause more heat transfer from the engine into the coolant and radiator. Low rated cap pressures result in boiling in the cylinder head creating a steam film that insulates the hot metal surface from the adjacent coolant.

If the thermostats are fully open, your foot is controlling the heat load. While the engine has plenty of torque with high torque rise meaning the transmission likely will not shift down, the engine speed does slow down some thus reducing water pump and fan speed. All contribute to higher jacket coolant temperatures. Shift down and keep the RPM up above 2000 as it will mean less fuel burned and lower heat rejection......the engine runs cooler.

Your challenge is how to measure that temperature drop accurately. With dash gauges it will not be good data. Unless you have access to some test instrumentation where you can measure the thermostat housing temperature and another port at or near the water pump inlet, you cannot measure this while operating the MH. use of infrared heat guns is not an option either unless you had the CAT on a chassis dyno pulling full load. Another unlikely situation as prolonged operation on a chassis dyno overheats the tires.

You could use the Simple Green cleaner mixed with less water or even full strength. Spray it on with a pump garden sprayer and let it soak. It may take several applications. Glycol ethers are potent cleaners but are water based making them safer than using petroleum solvents. One word of caution, do NOT inhale the vapors or mist. Wash out with strong garden hose spray or pressure washer. Simple Green contains a glycol ether with components that are good at removing hydrocarbon compounds (oil) as well as an alcohol-based cleaning agent good for non-hydrocarbon and water soluble contamination.

[spike45]

Originally Posted by RVNeophytes2

After I made an appt to have the system flushed and new coolant installed, I was on the creeper underneath and noticed that my hoses have material inside that crumbles when squeezed. In other words, she's clogged with scale!!

Stay tuned for results!!

Actually you were seeing hardened sodium silicate which precipitated from the coolant on the lower side of the radiator. At one time the cooling system had to have been filled with a LD auto coolant. Treatment of LD coolants with supplemental coolant additives can cause silicate precipitation. Usually this silicate remains a polymerized gel that is not coolant soluble. It become hard when exposed to air for some time.

It could also be that the coolant was Caterpillar ELC OAT coolant. Use of that coolant when mixed with hard tap water will produce some insoluble sludge as CAT ELC and similar OAT coolants do not use scale inhibitors like more robustly formulated conventional HD diesel coolants with SCA have.

Did you flush the cooling system with a cleaning agent to remove the "scale"? If you found it in your lower hose, it was in the lower radiator tank as well. True scale formations take place on the hotter portions of the cooling system, like the cylinder head and to a much lesser degree, the radiator top tank.

[gewilli]

Had to replace my 05 radiator, corroded off fins on the engine side. Likely due to deicer on the hiway as we take the rig up skiing everyweekend during the winter. Luckily caught it before it failed.

[RVNeophytes2]

Originally Posted by spike45

Actually you were seeing hardened sodium silicate...

My "scale" was in fact a shaping spring inserted into the hose.

I had the system professionally flushed by folks who are fast gaining fame in our area as a reputable MH service center, they reinstalled Motorcraft Premium Gold coolant, with superior anticorrosion properties.

These folks have a racing team and are motorhome enthusiasts.

Stay tuned for the first test run, pulling a 3800# Crosstour in 105F temps!!

[wagonmaster2]

Originally Posted by dball

Well, I did my radiator cleaning today. Again, I could do nothing effectively from the engine side. I used Simple Green and got lots of black material even during the application. I used a power washer (had NO problems with fin damage) and got loads of black drainage so I think I did some good. However, I still see very little light through the radiator when I place a drop light on the engine side. I have no experience with this so I don't know what I am supposed to see. It will be two more weeks before I take it back to the mountains. This time it will be the Smokies and not the Rockies. That won't be as challenging so I still don't think I will know if I really solved my problem. Somewhere I read that there should be a 20 degree temp drop across the radiator if it is doing the job of cooling adequately. Can anybody comment?
dball

That sentence about the 20 degree drop is very interesting. I'm having a little heating problem on mountain passes where the temp increases from the usual 192/194 up to 218-221 (221 is where the "yellow check info center" comes on. I cleaned the radiator just before this trip and again after returning ( no results on that one yet) but once the engine reaches operating temp (192) the right hand 1/3 of the radiator (passenger side) will read about 170-177 with an IR gun, the middle and left hand 1/3s will be in the 140s-150s. I guess the water from the engine enters the radiator at the top right side (standing at the back facing the radiator) and leaves at the lower left hand corner so maybe this is how it show flow.

I did notice that by holding a paper towel on the radiator with the engine running if flaps more at the top 1/2 of the radiator than at the bottom 1/2, like I still have work to do cleaning on the lower 1/2 of the radiator.

Still need to check the tension of the water pump belt to make sure it's not slipping some on the hard pulls.

Wagonmaster2

[spike45]

Originally Posted by wagonmaster2

That sentence about the 20 degree drop is very interesting. I'm having a little heating problem on mountain passes where the temp increases from the usual 192/194 up to 218-221 (221 is where the "yellow check info center" comes on. I cleaned the radiator just before this trip and again after returning ( no results on that one yet) but once the engine reaches operating temp (192) the right hand 1/3 of the radiator (passenger side) will read about 170-177 with an IR gun, the middle and left hand 1/3s will be in the 140s-150s. I guess the water from the engine enters the radiator at the top right side (standing at the back facing the radiator) and leaves at the lower left hand corner so maybe this is how it show flow.

I did notice that by holding a paper towel on the radiator with the engine running if flaps more at the top 1/2 of the radiator than at the bottom 1/2, like I still have work to do cleaning on the lower 1/2 of the radiator.

Still need to check the tension of the water pump belt to make sure it's not slipping some on the hard pulls.

Wagonmaster2

Actually, Wagonmaster2, the temperature drop across the radiator from inlet to outlet is 7F - 15F when the thermostat is fully open. That is difficult to measure on a vehicle without having thermocouple probes at the thermostat housing and the water pump inlet. I used to make those measurements on Caterpillar engines ...........a looooooooooooong time ago. Caterpillar published a tech publication entitled, "Know Your Cooling System" If you can get a copy from a Caterpillar dealer, do so. It is loaded with good information. Engines have changed a lot since that pub was first out. Cooling systems have not changed since then so the numbers and information are still good info.

Your simple test of the fan air flow is a good one.

[wagonmaster2]

Thanks Gary, I'll try to get a hold of that publication. I may have to try to rent a small power washer for the bottom half of the radiator if I can find one that's not too strong but more so than just the garden hose with the very small nozzle I have on it. Don't want risk bending any of the radiator fins. Everyone posts about all the dirt that washes out the bottom but after 7 years of washing the radiator at least twice a year all I ever see coming down the bottom is sudzy water. I spray the engine side and the radiator side with either Simple Green or Dawn soap with my garden sprayer, then using hot water in the sprayer give both sides a rinsing before turning the garden hose on both sides till all the soap bubbles disappear. Guess I'm still missing something in the lower half of the radiator slowing down the air flow.

Thanks again for all the replys on this subject here.

Wagonmaster2
2004 Meridian 36G Cat 330 C-7

[salvagediver]

Have you considered a good ol' radiator flush? Also, it's still best to not exceed the 50-50 mix of water & fluid as the water is what carries away the heat... Checking the cap seal and spring is always a good and easy check (especially if you can glom onto a cap pressure tester). Having the correct temp range themostat is often forgotten. Finally, all us guys with old BMW 2002's have had our radiators re-cored or substitued larger 320i radiators AND use Water Wetter to help beat the heat.

You guys may know all this stuff, just offering a few lessons from the school of hard knocks.

[1ciderdog]

I spray simple green and/or dawn into the radiator from under the engine with it running at idle speed. My theory is the fan will spread it and push the cleaning solution into the radiator(s) - then I follow up with garden hose. I do get wet and dirty while doing this but I also get a lot of black water out - not to mention a gazillion bubbles. My concern with this is I might get spray on the alternator or other water sensitive part but so far so good.
Safe Travels
Bob

[texnet]

Originally Posted by RVNeophytes2

My "scale" was in fact a shaping spring inserted into the hose.

I had the system professionally flushed by folks who are fast gaining fame in our area as a reputable MH service center, they reinstalled Motorcraft Premium Gold coolant, with superior anticorrosion properties.

These folks have a racing team and are motorhome enthusiasts.

Stay tuned for the first test run, pulling a 3800# Crosstour in 105F temps!!

You must have had your MH worked on by Thomas Myers at Myers Automotive! Thomas is a great guy and does quality work.

[salvagediver]

Originally Posted by 1ciderdog

I spray simple green and/or dawn into the radiator from under the engine with it running at idle speed. My theory is the fan will spread it and push the cleaning solution into the radiator(s) - then I follow up with garden hose. I do get wet and dirty while doing this but I also get a lot of black water out - not to mention a gazillion bubbles. My concern with this is I might get spray on the alternator or other water sensitive part but so far so good.
Safe Travels
Bob

I wrap the altenator and any electrical junction boxes with saran-wrap before hosing the radiator...foil works too, but remember you have live juice directly on the back side of the alternator and that can light up your life...if you make the connection.

[Airtool]

I use a Karcher Electric pressure washer to clean the radiator and intercooler. It putouts around 1700psi and has worked very well for me.
I'm on my second one because I have used them to clean more the the MH radiator. Clean the Engine area, Battery's and the compartment plus the deck and deck chairs.
I have packed it in one of my storage areas when we take extended trips,so I can clean the outside when needed and have it, if the radiator gets real dirty from construction areas and dirt roads.
It only uses 1.5 to 2 gal per min,so I have been thinking of installing a water connection from the water pump so I can use it when boon docking should the need ever come up.

Dick.

[1ciderdog]

1700 PSI - doesn't that bend the fins on the radiator?
Bob

[Bill Adams]

Not when used properly as the strength and width of the spray is adjustable.