Sprinter turbo intake hose slippage causing limp home mode
Hello Sprinter chassis owners. Several instances of Sprinter Turbo Resonator failures have occurred in which the vehicle has gone into “Limp Home” mode going up steep hills, which resulted in the vehicle slowing abruptly and almost being hit from behind by a following vehicle. In at least two cases that we are aware of, the following vehicle was an 18 wheeler traveling at highway speeds. In this failure mode, the Sprinter slows to a crawl almost immediately with no visible warning, because the BRAKE LIGHTS DID NOT COME ON. Typically, the driver has his or her foot on the gas pedal.
What we have just learned is that this same situation can occur even if the resonator does not fail. If the intake hose, which is under high boost pressure, suddenly “pops off” the stock resonator (or “pops off” the billet aluminum resonator eliminator), the effect on the vehicle is exactly the same as a resonator failure.
In one instance reported to us, a dealer had just replaced a stock resonator with another stock resonator. The Intake hose “popped off” the turbo resonator not long after leaving the shop and the vehicle was nearly rear-ended. Upon investigation and review we duplicated this problem in our shop. We discovered that as the tightening screw advances along a series of “indented” grooves in the clamp “strap” it is possible when re-using this type of clamp for the screw to deform the indented grooves in a manner that prevents the clamp from tightening fully, while at the same time, providing a false sense of “tightness.” Literally, the clamp can be tightened as hard as you can turn it and it can still be loose enough to allow the intake hose to “pop off”, under boost pressure, which is quickly followed by a “whoosing” sound of rushing air from the passenger side of the engine and then the vehicle immediately slows down into “Limp Home” mode. You may wish to use an “Ideal” brand 1&3/4 inch-to-2&3/4 inch, stainless steel “worm drive” screw clamp available at most automotive or hardware stores. These clamps have actual SLOTS for the screw to grip through, instead of the “indented grooves” found on the stock clamp and they do not give a false sense of tightness. On our own Sprinter we have installed TWO of these clamps, one behind the other. Hope this helps some of you avoid this problem. Best regards, Jim Riordan