Cummins Intake Manifold Sensor Failure

[NorthernFocus]

The previous owner of my R25 reported having had a failure of the intake manifold pressure/temperature sensor. It appears to be on the fritz again reading erratic inlet air temperature and zero boost pressure when the engine is running. Both signals are used by the ECM in calculating fuel injection rate. Having two failures over the course of a couple off seasons is a bit worrisome. Or just darn bad luck.

So my question to the community as follows: Are sensor failures a chronic/recurring problem on the Cummins or is mine an isolated situation?

Thanks,

 

[knotflying]

Are you sure it is the sensor? I have a Yanmar and I had a recurring problem with the turbo pressure. It turned out that the vacuum hose that operated the waste gate kept slipping off. Once I secured it with a better clamp all is fine. I'm just thinking that perhaps there is an underlying issue. Although it may have been addressed with a mechanic replacing the sensor and when working on the boat also securing a vacuum hose and not saying anything and now the hose may have slipped off again. I am not sure if there is a similarity in components between the Cummins and Yanmar, but it may be worth a look.

 

[NorthernFocus]

Thanks for the response.

Both temperature and pressure come from the same sensor and both are affected. So it appears to be either the sensor or an electrical issue with the plug and/or harness. So far I've only done a cursory inspection of the plug/connector. That's what I'll do next prior to ordering a sensor. A detailed inspection and perhaps a bit of "tune-up grease" if nothing found wrong. I just figured I'd check here to see if others have had issues with the same thing. Typing on the laptop is easier than twisting my creaky joints into the positions necessary to effectively troubleshoot the problem if it a known issue already 😉

 

[Commander Ed]

I had to replace the same sensor on my R25 with Cummins engine at the 3 year point. It is in a very inconvenient place (blocked by the door step into the cockpit.) I had the same sensor reading, and could not get any boost pressure - limiting me to about 7 knots. I had the Mercury Marine Rep come help troubleshoot and replace the sensor. He did a good enough job, but unfortunately they were in the middle of the Mercury folks taking over the support from Cummins. Fortunately I had invested (about $100) for the detailed Cummins Manual - which helped the Rep and I understand what the problem really was. Once the sensor was replaced - all better, but it took 2 days with both of us working on it. Not sure if this will ever recur, but have had 3 years with the new sensor.