Engine heating

[jagan]

Have 2001 Itasca with Cat 330. Had problem with temp gauge showing over heating with alarm coming on. Conditions were, running 65 MPH into a strong head wind, running chassis AC and outside temp 103 F. I would pull over and temp gauge would drop. If I reduced my speed to 60 MPH, with no AC running, the temp gauge would stay in the middle heat range, but as you know no AC @ 103 degrees is tough. This was a 300 mile trip. Any ideas, Thermostat or guages. Had plenty of coolant. Do you think I should blow radiators with air or water to see how dirty they are? I have been told that my chassis AC fans on the outside (visable) should run full time when I have the AC on. Is this correct?

[Martind4]

My guess is that you're suffering from the classic rear radiator that needs cleaning. The Cat engines have a crankcase vent (slobber tube) that provides an oily mist that gets sucked into the charge air cooler and radiator, thereby attracting all the road dust and debris

Do a search on engine overheating and you'll find more information than you care to know. If it hasn't been cleaned in a while, it might take several cleanings to get it clean.

When you get it clean, be sure to modify the slobber tube (also a search item) so you only have to clean it once a year.

Good luck

[Gary D]

Having had the same problem with our 2005 Meridian 350 C7 I would agree with getting the rear rad and CAC cleaned. While travelling in Death Valley the engine overheated requiring pulling over to get engine cooled down.

I had the engine and CAC steam cleaned at Freightliner and problem solved. Now engine temperature holds between 187F - 196F.

Searching the forum, many others with the same problem have suggested many ways to get the slobber tube venting away from the rear fan intake. I piped the slobber tube to the rear behind the rear mud flap using 1 inch copper pipe.

There is also another contributing factor to crankcase vent oil being excessive. Caterpillar have issued an update to reduce the amount of oil to be used from 21 quarts to 19 quarts for the C7 shallow crankcase.

I also had the oil dip stick recalibrated to be consistent with the recommended oil reduction. The amount of oil now being vented is minimal.

Good luck.

[MaverickBBD]

Yes find a place or rent a wet steamer and clean your rad. & C.A.C. Also remember to keeps your r.p.m.s up. Try taking some of the load off by running genny and using house air too.

[ernieh]

If your temp was hot enough to sound the alarm, you have a problem as others have suggested. I was just in similar conditions two weeks ago and my temp increased from the normal 1/3 scale to a little over 1/2. My cooling system is in good condition, but 1700 rpm is just not going to move enough air under those conditions. You need to be turning around 2000 rpm to maintain normal temps under those conditions, even when everything is working as it should.

[jimmccreary]

I agree with others since I had the same problem too. I would have described it as overheating on a long pull, but given your speed and head wind you may not need to be going uphill in order to overheat. In my case the overheat warning came on in my info center. You can confirm a clogged radiator problem by crawling under the engine behing the passenger side rear wheel. From this angle, with a flashlight you can see the radiator just behind the fan blades. you can move the fan blade by hand to get a better view. In my case the viewable portion of the radiator was covered with a greasy sludge.
Follow the cleaning recommendations from others in the past. By the way I used 1:1 simple green to water to degrease the radiator front side and also sprayed it into the rear of the CAC.
A 2000 rpm aslo helps.

hope this helps,
jim & debbie, 04 journey, 34H 330 Cat C7

[AZgl1500]

If you are going to pressure clean the radiator yourself, please use extreme caution to not get too close to the fins, nor do you want to get OFF of a 90* perpendicular angle to those fins. The fins are very fragile and will flatten out in a heart beat if you hit them sideways or too hard with a hard water stream.