Temp Higher After Coolant Change In Cat 350

[bigdgr]

When I drove home after having the local Cat dealer flush the cooling system and install ELC coolant the operating temperature was about 10-15 degrees above where it normally runs. Is this normal with a change from regular auto anti-freeze or could something be wrong? What is the optimum operating temp ? Thanks, Darrell

[wolfe10]

No, a coolant change should not change operating temperature. But, Caterpillar recommends changing thermostats (called regulators) every three years. So, they may have change the thermostats which could change operating temperature.

What are you reading-- and is it on the dash gauge and/or Silverleaf or other monitor system?

It is also possible that you have an air lock in the thermostat housing.

Be sure to check coolant level, as it air may be migrating to the overflow tank.

Brett

[MikeCanter]

Darrell, what was your water temp before the coolant change and what is it now? I believe my thermostats are 188* units. So at 188* they start to open and then fully open by 205*. My engine will stay right around 188-190* unless under real load. Did they change the thermostat? Are you a rear radiator or a side radiator coach? If you are a rear radiator coach then maybe it is time to get a couple of cans of Gunk spray engine cleaner (any parts store or Wal-Mart)and spray the whole radiator from both sides and let it soak for about five minutes and hose it out from both sides. The CAT motor has a real problem with the slobber tubes venting a fine mist of oil that is sucked up by the radiator fan on gets on the rear radiator units then the dirst sticks to the oil and plugs then up. If you have a rear radiator unit then you should clean that radiator with a spray engine cleaner at least once a year.

Just as a note here...write down what coolant they used and file it away so if you ever need to top it off in the future you can use the same brand of coolant.

[bigdgr]

Dear Brett and Mike, I have a dash gauge which would set at just past the 170 mark at what I guessed would be around 180-185. On the way home after the coolant change it was running just shy of the mark midway between 170 and 235. I guessed this as around 200. I do have a rear radiator which I try to clean after each use before the coach goes into storage. The service man had me back into the steam bay so he could clean off the back of the coach before I left. Do you think that some of the old coolant got on the radiator ? I drove about 40 miles from the Cat dealer to my storage. I wasn't charged for a new thermostat so I doubt one was installed. I told them to drain and flush the system, check the hoses, replace anything they felt needed replacing, install a new belt and fill with Cat ELC coolant. Based on Mike's engine where my gauge is running now should be about right. I was just concerned with the change and possible problems. Thanks again for the input and hopefully we'll meet in Madison. Darrell

[MikeCanter]

There is no reason the old coolant would have gotten on the radiator and even if it did it would hurt anything unless it caused dirt to stick over time. When that engine cools down you should check the coolant level and see if it burped air. Does your cooling system have a little petcock that allows you to bleed air out of the system. Sometimes these are located behind and above the radiator and look like a drain petcock. If so then put a catch can under it and open it up when the engine is running and leave it open until coolant runs out of it. How hot was the ambient air temp when you drove it?

[wolfe10]

Two recommendations.

Caterpillar Corp recommends changing thermostats every three years. I believe your C7 has two in the same housing. I would replace them along with the gasket. They are not expensive or difficult to replace.

Also, you mention cleaning the radiator from the back. The vast majority of the dirt will be on the front (front of coach) of the CAC. It is not possible to clean that dirt from the back. To see if this may be an issue, access the top of the engine from the bedroom or closet. Shine a strong flashlight inside the fan shroud/between fan blades. Insure that the perimeter is as clean as the center (the blades sling the dirt to the perimeter).

And, yes, we will be in Madison.

[hermanmullins]

Two recommendations.

Caterpillar Corp recommends changing thermostats every three years. I believe your C7 has two in the same housing. I would replace them along with the gasket. They are not expensive or difficult to replace.

Also, you mention cleaning the radiator from the back. The vast majority of the dirt will be on the front (front of coach) of the CAC. It is not possible to clean that dirt from the back. To see if this may be an issue, access the top of the engine from the bedroom or closet. Shine a strong flashlight inside the fan shroud/between fan blades. Insure that the perimeter is as clean as the center (the blades sling the dirt to the perimeter).

And, yes, we will be in Madison.

Brett,

There are cleaners that A/C people to clean evaporators and condensers. A/C parts store have it in stock. It come in a spray can and after a short wait it can be rinsed with water. The instructions are very clear. But as always, do not use a high pressure hose to wash with because it can bend the fins. I would think for rear radiator you could spray through the inside (bed or closet) and hose from the outside. Be sure and do the cleaning where the mess on the ground wont bother you or the environment.

Good luck.

[wolfe10]

Herman, et al;

On paper, shooting water through from the back would clean the radiator. The problem is that most rear radiator coaches are SANDWICHED cooling systems. No way for water shot from the back of the coach to go through the radiator, air gap, CAC and still have enough force to knock dirt off the front of the CAC where it is deposited. Were you to used enough PSI to do it, you would surely bend the fins of the radiator. That is why these sandwiched cooling systems have to be cleaned from the front.

No, it is a "no fun" job. Nothing complicated, just dirty/messy.

But driving a "40 vacuum cleaner" down the road requires at least annual cleaning of the front of the CAC. The number of rear radiator coach owners complaining about overheating, when they did not do that when new attests to the clogging of the cooling system.

[MikeCanter]

Let me just make sure we understand that just squirting water on these rear radiator and CAC units is not going to get all the dirt out from between the fins. The reason the dirt is sticking is that the slobbber tube has sprayed a fine mist of oil on the CAC and radiator that is then mixed with the dirt sucked up from the road. You have to use several spray cans of engine degreaser to cut that oil from both the front and back of the whole unit. I find that the orignal Gunk engine degreaser spray is the best. If you take care and aim you can get that spray degreaser in between all the fins on both sides. I did it successfully for years. After the degreaser has soaked for a few minutes and cut the oil the dirt will hose right off without using a too of a high pressure stream.