MarinerCoachman

Overheating Cat 330-Discovery

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It is a combination viscous and electric clutch. The viscous works to certain point when the fluid thins out from temperature then a temp sensor activates the electric clutch allowing full engagement for maximum cooling.

According to the Freightliner help line they are still using these. The purpose is to reduce the horsepower used to run the fan in light load conditions thus saving fuel.

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Gwheel   

I have a 2004 Alfa with the 330 Cat and we keep having an issue with the top radiator hose blowing off the radiator causing all the coolant to spray out. We have replaced the thermostats to see if that would fix the 215 temp problem. We have had to pull over more than 17 times to put the hose back on. Any suggestions?

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Hi Gwheel ! Welcome to FMCA !

Sounds like a restriction in the Cooling system other then the thermostat. The hot side of the cooling loop, generally the top radiator hose heats up rapidly once the thermostat opens.

The other possibility is a restriction in the overflow system line or a defective radiator cap. This will show up as no change in the level of the overflow tank level from cold start to hot.

Have you tried to run the heater fan on high to see if you get constant heat output from the heater ? Does running the heater fan on high extend the time it takes to raise the engine temperature ?

If so then the water pump is operating properly. IF Not-Might point to an air pocket in the cooling system causing a blockage of coolant flow or as a cavitation in the water pump. This would also reduce or limit the amount of heat coming from the heater core running on high fan speed. Should the heater work well then.

That would lead one to the engine cooling loop, including a restriction in the radiator, possible restriction(s) in the upper or lower radiator hose(s).

Hope these thoughts put you on track to finding the problem.

Rich.

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We have a 2003 Newmar Dutchstar, Freightliner chassis, Cat E-3126, 80,000 miles. In the past we have pulled a loaded three horse trailer over 7,000 ft. passes without a problem. Now we are overheating crossing the Cascades (3,500 ft.). I have drained, flushed and replaced the coolant with proper coolant. Today I removed the side radiator grill, loosened the condensers, treated with de-greaser and pressure washed. That being said, I am concerned that the speed sensor on the hydraulic radiator fan is not increasing the speed when needed. Last trip I pulled into a rest area at the top of a 1,800 ft. climb, temp gauge was about 210 and the fan was not particularly noisy. Where is the sensor and how do I replace it?

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R03Dutchstar,

Welcome to the FMCA forum!

With 80K on the coach, have you ever had the hydraulic fluid and the filters changed?

Water pump belt tension and thermostat replaced?

Rich.

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jleamont   

Keep in mind if your radiator cap is releasing pressure too soon it will cause the coolant to boil prematurely. See the chart below. Call me crazy but when I service a cooling system for repairs or a flush I either test the cap or just replace it.

Table #2
lists the boiling point of water at a particular pressure

propan5.jpg

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Looks like I'm going to have to replace both Thermostats (Regulators) on our 2003 Newmar Dutch Star with the 3126 Cat 33 HP engine. Anyone have a detailed map, set of instructions to do this job...?

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wolfe10   

Brad,

Drain 2 gallons or so of coolant.

Access the top of the engine: under bed or closet-- you need to get to the top front of engine (back of coach).

The thermostats are under the top radiator hose. Pretty easy to get to.

Make sure you remove all the old gasket and USE A NEW GASKET.

Pour the coolant into the thermostat housing until just below overflow level (this prevents an air lock when starting the engine).

Install thermostats and gasket.

Pour remaining coolant into radiator/overflow reservoir. May not take all of it until engine started, warmed up and cools down.

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I did exactly that. Our 2005 C7 continued to get hotter and hotter to the point I had to climb hills in 1st gear to spin the motor fast enough to keep it from melting. When I got home from that trip I pulled the engine cover from the floor of the closet. I bought a yard sprayer from the hardware store for $14, bought 2 gallons of Industrial strength, non corrosive Simple Green. I used the yard sprayer to spray the simple green onto the charger air cooler and engine fan from the engine cover in the closet, then I sprayed the simple green on the radiator from behind the coach. I waited about 30 minutes and took a garden hose inside the coach and sprayed the charge air cooler with water from the engine cover in the closet using a power nozzle and being careful not to bend the fins with too much pressure. Then I went outside and sprayed the back of the radiator with water the same way, doing both until clear water came out. I cut the blow by tube a little shorter, clamped on a 90 degree elbow and threaded about a 4' piece of pipe to the side of the motorhome ( I made it long enough to be sure it went further back than the radiator) so that the blow by oil wasn't picked up by the engine fan and blown directly into the charge air cooler and radiator. You have to be sure to do all of this in a place where you can recover the oil that comes out of the radiator and charge air cooler and not let it seep into the ground. I've put 10,000 mile on it since then and it hasn't overheated one time. It's a messy job but when you consider that the local Cat dealer wanted $3000 to seperate the charge air cooler and radiator, and clean it that way, it's well worth it. 

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manholt   

Welcome.

Well done, it goes better with practice.  I do mine in March and your right about saving a lot of $$$$ by DIY!  I have a side radiator, so I do mine from laying on my back...I wear an old dive mask and TYVIK coveralls that I get at the paint store and rubber maid gloves that Linda tapes over wrist....Still get dirty.  I use a steam power sprayer.

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wolfe10   

With a side radiator, you can get most of the dirt off from the OUTSIDE, since air (and dirt) flow from outside to inside.

Said another way, the CAC collects most of the debris (on either rear or side radiator designs) as it is the first thing in the cooling package and "filters" out most of the debris.

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Side radiators are not near the problem that rears are. The side panel on a big CAT Safari was originally a fixed panel riveted numerous places yet on a hinge. I drilled all the rivets and put two bolts in the bottom keeping it in place. Now for the annual wash/rinse remove them and open, no more trying to get through the louvers.

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10 hours ago, blakleyfamily said:

Extending the blow by tube to the side with a piece of pipe is a huge help.

 

I added a catch jar on my slobber tube. I used a large plastic container somewhere around 2 qt.+ drilled a hole in the cap that the hose would fit through added a hose clamp so it couldn't pull back out. You need to drill some holes around the top area (the same or more total area than the area of the ID of the OE hose) to let the pressure out and not cause any back pressure. I have rinsed it out a couple of time and don't find any large amount of oil in the bottom of the jar. 

Bill

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I've been thinking about doing that. The other thing folks need to consider on these rigs is that when Freightliner puts the oil pan on there are two differen pans. A long one, and a short one. The long one hold 23 quarts and the short one holds 19 quarts. Putting too much oil in the short pan is not only bad for the motor but causes more oil to blow out the slobber tube. There are also 2 different dipsticks, I changed my oil and put in 19 quarts and when I checked it looked like it was a gallon low on the dipstick so I made a new mark on the stick to indicate where it was with 19 quarts. A picture of the slobber tube catch can you made would be great.

Thanks and have a great day,

T.

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wolfe10   

Actually, Caterpillar did make two different pans,  a shallow pan (stamped steel) and a deep one made of ribbed aluminum. To my knowledge, Safari (Magnum chassis) is the only one who used the deep pan. Deep pan capacity is quite a lot more than shallow pans-- 29 qts with filter.

Best to confirm oil capacity by calling the Caterpillar RV Hotline with your engine serial number: 877 777-3126. The reason-- Caterpillar DID change their capacity recommendations for some engines!

And totally agree, calibrating the engine oil dipstick is an excellent idea, and FREE at an oil change.

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