Cat 13 overheating

[Terry Melot]

I know this has been addressed before on here.  Searched the forum and couldn't find it.

Have an 05 Thunder purchased 7 weeks ago. On first 1000 miles when going up a hill, the normal 192-4 temp would start to climb. Around 200 it would start to drop, still in the climb. I figured; ok, the Tstat opened up or the two speed fan kicked to high.  Started toward Phx last week. Noticed on long grades the temp would just keep climbing.  Coming into Vegas on 160, a long steep grade, around 100'F outside temp,  the engine temp just kept climbing. Trying keep the rpm up and slowing. Got down to 30 mph in 3rd (around 2,000 rpm) and temp climbed to 230'F and the engine cut back. This occurred several times before reaching the summit. I have since cleaned the radiator with Simple Green and garden hose. Didn't get much out it.

Questions is; is the thermostat sticking or the two speed fan not going to high. Leave for Phx tomorrow and expect more hot weather. I read on here some time back of someone having trouble with the two speed fan and disconnected the control to it, leaving it running in high speed all the time.  Anyone know how to do that?
No time or possibility of changing the Tstat tomorrow, but if I could keep the fan running on high, I would.

[Edward Buker]

Terry,

Be sure that the cooling system is full. Sometimes the overflow/expansion tank will have fluid in it but the block and radiator will not be full. Check by adding and see it takes in fluid or just completely fills the expansion tank and wants to overflow. If full I would look to have the thermostats replaced as a precaution and have Cat look up the history by serial number of your motor and see if there is a history of overheating and what has been done to it. If possible contact the prior owner and see if this is normal for this particular coach or something has changed. 230 is getting up there but I do not own that year and model so I do not have an experience base of where this version of a Pat Thunder runs temp wise. Maybe some other owners can chime in...

What is above are the simple things regarding looking at an overheating issue. Fan speed, plugged radiators, water pump issues need some expertise to diagnose. The folks in Bend may have some ideas on who might best diagnose your coach if it turns out to be a more complex issue.

Later Ed

[Gerald Farris]

Terry,
The 05 Thunder does not have an overheating problem as a rule. The most likely problem is low coolant level, so be sure that your are full of coolant before doing anything else. Next check the fan speed at operating temperature.

If you can not find anything and you want a repair shop, I have heard that Massey Diesel in Phoenix does good work.

Gerald

[Orman Claxton]

Massey Diesel does great work, I would call Tom and see if he can get you in, they are usually pretty busy

[Roy Warren Co-Admin]

Terry,
One problem of the 2005 Patriot Thunder is the plastic coolant tank doesn't always have a good pressure cap.  Make sure it is a closed system and will maintain the 14 lbs of pressure needed.  You might have that checked before you leave.
Roy

[Terry Melot]

OK, thanks, guys. The plastic fill tank is right where it should be for "cold". I have no way of checking the fan speed, as it would need to be at 200'F to go to high.
It will only get there after a long hard pull. However, if I have to pull over tomorrow because it is getting close to 230, I will go back and check it.

[Terry Melot]

OK, thanks, guys. The plastic fill tank is right where it should be for "cold". I have no way of checking the fan speed, as it would need to be at 200'F to go to high.
It will only get there after a long hard pull. However, if I have to pull over tomorrow because it is getting close to 230, I will go back and check it.

[Larry Fisk]

I have  the same unit and I'm wondering how hot is too hot? I have seen my temp get up to 216 on a long grade and wondered if I was overheating the engine. Is that considered normal? Also when I went to the extended life coolant the tech said he installed 195 degree thermostats instead of the 185. I would think the 185 would have been better.

[Joel Ashley]

I've never quite grasped the principle myself, Larry, but it works.  On our old Pace Arrow, when it went through an overheating spell a "warmer" thermostat was put in and it performed much better.  In my mind, a tstat stays closed to allow faster warmup upon starting, then opens at the prescribed temp. to begin circulating fluid through the radiator.   A "warmer" one would just stay closed a few degrees longer and seemingly circulate actually hotter fluid until the radiator comes into play.  

Exactly why the tstat even plays into the picture during temps well above and beyond their "open" setting is above my paygrade, I reckon;  but it apparently does.  Perhaps others here more astute about the idea can enlighten us.  

I'm going to guess that as with refrigeration principles, it has to do with pressure.  Perhaps if a "warmer" rated tstat stays open longer, the pressure in the radiator is lower, allowing more evaporative cooling?

Joel

[Edward Buker]

Terry,

Even though the tank shows that it is where it should be cold that does not mean the block is full. Add until you are feeding coolant down the main pipe feed to the engine and see if it takes any.

Later Ed

[Terry Melot]

No heating problems between Vegas and Phx today.  It was a little cooler (90) but never saw over 217 at the top of the long climb south of the Boulder dam bridge. I read in the Cat owners manual that the coolant should be changed every 3 years regardless of miles. Good time to change the Tstat as well. There is also a "boil out" that Cat recommends to remove scale from the radiator and engine. Since I have no maintenance records from BCS, I'll assume it has never been done.
Will have them check the fan for proper operation while at the diesel shop.  Thanks guys, for all the suggestions.
Oh, also, the generator kept the house batts charged all day.  Who knows what that was?

[Peter and Connie Bradish]

We are the ones who had the over heating problem.
We have a 300 Cummins. It turned out to be the hydraulic divider. Our two speed engine fan never ran on high so we would overheat on climbs because the fan would stay on low. We had a solenoid which we could disconnect and the fan would run on high all the time. But that obviously was not the solution to the problem.
We can recommend Jeff of Bend RV Repair in Bend Oregon. He will wrestle the problem to the ground and fix it. We finally got a fix for our problem. As we are older and getting parts is a problem. Jeff redesigned our system and we now have a working hydraulic pump and fan system.
Connie B.
PS our engine overheating light goes on at 215 degrees F