Safety Concern: Possible Fire started from charged air to air cooler Caterpillar C-13 side radiator.
Roy Warren’s C13 experienced low power and was in a shop for a stuck turbo wastegate but the service shop could not locate the low power problem. They then traveled 2000 miles with problem getting worse. Roy and Vicki bought their motorhome to Dave’s Diesel in Quartzsite. AZ. We connected the Cat ET to their Caterpillar C-13 looking for fault codes pertaining the low power problem but found nothing out of place after reading out engine ECM data. Vicki then asked Roy if he had told Dave about the high noise and smell of burning rubber. Vicki went on to explain every time she would go to the back of motorhome while Roy was driving something did not seem right.
Thanks to Vicki’s information Dave changed subject and suggested low power root cause could be due to the charged air cooler (via the rubber hose coupling from charged air cooler piping or a crack in charged air cooler). The next morning we started inspection and tear down. This is what we found.
The discharge tube coming from the turbo charger to intake to the charged air cooler (note: heated air from turbo charger enters the CAC at temperature from 330 Deg F to 400 Deg F). The problem or point of possible fire location was the piping and rubber connector boot jamming tight into top corner just behind driver side rear wheel. Dave could see with a flash light the silver rubber backed sound suppression was charred and the corner rubber melted, charred as well as warped metal on top and side toward rear wheel. That said, it is totally impossible to reach the band clamps connecting the rubber connection boot to the CAC.
Not liking what we were looking at and unable to reach the problem area we decided, after talking with Roy and Vicki, to cut an access opening under the bed to reach the band clamps on rubber boot. What we found was the heat conduction from a hole in rubber boot to CAC along and a crack within the CAC itself. The heat warped the metal as indicated above and about a 12 inch area of carpet under the bed was discolored due to the heat with the rubber backing on carpet melted. This is the source of burning rubber Vicki smelled.
Fast forward to now and both Dave and Gale, his partner, verified that with poor builder design and lack of understanding (The What happen If , happened ) nobody ever dreamed a rubber hose would break down over a period of years along with crack in the CAC resulting in blowing
extreme heated air directly into the rubber sound suppression after melting rubber approximately 1 inch in thickness in top outside corner and warping metal and conduction of heat to under carpet inside of motorhome under bed.
Dave would suggest owners of any motorhome with side radiator take a real close look at the CAC piping connection boot and connection to CAC and area in the top outside corner for any signs of discoloring of the sound suppression foam of charred blackness directly in the top corner.
Lastly the installation of a CAC with a 200 pound hydraulic fan fasten on top of the it and bottom of radiator without the hydraulic fan being supported independently of the radiator is a very poorly thought out design.
In closing, as our coaches age problems are starting to surface. Also Thanks to Vicki Warren for pointing us in the right direction by relating something weird that gave us the additional information about a problem that had the making for a very bad ending.
Dave Atherton Retired Cat Mechanic