rvrepairnut
bc
Senior Member
Joined: 11/11/2011
View Profile
 Offline
|
A friend has a 300HP CAT that runs hot pulling hills.Anyone know of the type of cooling fan system on these units.I have seen where people say the rear cooling rads get very dirty compared to side cooling? Is the 300CAT known to run warm?
Thanks
|
Big Katuna
Deland, FL
Senior Member
Joined: 12/27/2003
View Profile
Good Sam RV Club Member
Offline
|
The CAT is not known to run hot. I am guessing his rad is dirty. Yes, rear rads are more susceptible to oil blowby (did he route is slobber tube past the rad?) which then picks up dirt. I have never had a problem but I clean mine from both sides annually. He could also try downshifting a gear which ups the RPMs, which moves more water.
My Kharma ran over my Dogma.
|
wolfe10
Texas
Senior Member
Joined: 10/08/2000
View Profile
Offline
|
No,very rare for overheating to be an engine issue-- whether on Caterpillar or Cummins.
If rear radiator, access the TOP of the engine from the bedroom or closet.
Shine a strong flashlight inside the fan shroud/between fan blades. You are looking at the front of the CAC (Charge Air Cooler), the radiator is behind it.
Make sure the perimeter is as clean as the center (the fan "slings" the dirt to the perimeter). Pay particular attention to the lower part.
Suspect you will find quite a lot of the surface of the CAC will be blocked off by dirt.
Brett Wolfe
1993 Foretravel 36' U-240
Cat 3116, Allison 3060
FMCA Forum: www.community.fmca.com/index
Caterpillar RV Engine Owner's Club: www.catrvclub.org
|
sch911
Rochester Hills, MI
Senior Member
Joined: 04/13/2003
View Profile
|
Keeping the radiator airflow path clean is a good thing to do. But, all engines will reject more heat when climbing a grade. How hot is it getting? Are you sure it's not normal?
Chrysler/Dodge/Ram/Jeep Engineer
2003 Damon Challenger 348 Class A - F53 Triton V10
|
Big Katuna
Deland, FL
Senior Member
Joined: 12/27/2003
View Profile
Good Sam RV Club Member
Offline
|
sch911 wrote:Keeping the radiator airflow path clean is a good thing to do. But, all engines will reject more heat when climbing a grade. How hot is it getting? Are you sure it's not normal?
Good point. Just because the temp guage goes up doesn't mean its hot. Need to know what temp it is going up to.
|
|
|
jauguston
Bellingham, WA
Senior Member
Joined: 07/03/2005
View Profile
Offline
|
Rear radiators need regular cleaning. They need to be forcefully flushed with water after a soak with a good detergent. I spray a strong solution of Spic and Span with a weed sprayer from both front and back. Then flush with a 1500 psi electric pressure washer. A hose with a nozzle if you don't have access to a pressure washer. Repeat until the flush water is running clean onto the ground. Pay special attention to the area outside of the fan circle in the corners. Most of the dirt will be in the CAC that is closest to the fan. The radiator is behind the CAC (intercooler).
If it has not been done add a hose to the slobber tube and route it below and behind the radiator.
Jim
2005 Coachman Sportscoach Elite 402 40'
350hp Cat C-7 w/MP-8
7500w Onan quiet diesel generator
6-Kyocera 130w solar panels SB3024i MPPT controller
Pressure Pro TPMS
1987 Suzuki Samurai tintop Toad w/VW 1.6 turbo diesel power
|
wolfe10
Texas
Senior Member
Joined: 10/08/2000
View Profile
Offline
|
Big Katuna wrote:sch911 wrote:Keeping the radiator airflow path clean is a good thing to do. But, all engines will reject more heat when climbing a grade. How hot is it getting? Are you sure it's not normal?
Good point. Just because the temp guage goes up doesn't mean its hot. Need to know what temp it is going up to.
I have a slightly different perspective. If the engine temperature rises more than a few degrees from thermostatic controlled temperature except under extended high throttle conditions in hot ambient temperatures, I would look at the cooling system, particularly with a rear radiator configuration.
The reason-- even before your cooling system is blocked enough to cause coolant temperature to run too hot (thermostat wide open, but not enough heat dissipated in the radiator), the CAC, likewise is not able to dissipate the heat it is supposed to. So intake air gets hotter and both performance and MPG go down.
|
rvrepairnut
bc
Senior Member
Joined: 11/11/2011
View Profile
Offline
|
OK
I have read all responses and will go look and see if the rad core is dirty externally and go from there.He says its getting very hot on the gauge and the alarm is going off.I was wondering what type of fan cooling clutch system these engines use?
|
wolfe10
Texas
Senior Member
Joined: 10/08/2000
View Profile
Offline
|
You don't say what chassis it is on, but the vast majority of rear radiator coaches have direct drive fans (no clutch system).
And, hot enough for the alarm to go off answers many of our questions, as that is WAY too hot.
BTW, when you look inside the fan shroud, you will NOT see the radiator. That is the CAC (Charge Air Cooler= After-Cooler= Inter- Cooler-- different names for the same thing, an air to air heat exchanger that cools air exiting the turbo before it goes to the intake of the engine). The radiator is behind (toward rear of the coach and visible from the back of the coach).
Without knowing the age or mileage of the unit we really can't offer other advice. Check out the front of the CAC first, and if the overheating continues, give us some more facts to work with.
|
sowego
northwest panhandle of Nebraska
Senior Member
Joined: 03/14/2006
View Profile
|
When we were newbies our 1st year out...our CAT 330 got hot on hills...even smaller hills. After going through the whole process to rule out mechanical problems and cleaning the radiator...it still ran hot.
The simple answer was - we were not manually downshifting on grades to keep the rpm up, therefore improving the airflow through the cooling system to prevent overheating. We thought that Allison would take care of all that. The transmission will downshift somewhat on hills but not enough to keep you running cool. Drop down 2 or 3 gears upshifting as you crest the hill.
If that does not solve your issue then it will take further investigation.
2002 Tiffin Phaeton
2005 Malibu Maxx toad
|
|
|
