Low power mode - no error code on W176 220cdi

[stevenkeyte]

Greetings to everyone here,


My vehicle is a W176 2014 2.1 cdi.

fixed a DPF fault and an exhaust pressure sensor fault since I purchased it; still working through a few other difficulties.

I was a heavy-vehicle mechanic for a while, but I left that field years ago. Lately, I've been thinking that maybe a boost fault is to blame when the car goes into limp mode at higher speeds and boost levels, albeit it happens less frequently while idling. I have examined the vacuum lines and air intake lines for signs of wear, but they appear to be in good condition.

Last night, I conducted a smoke test. I started by checking the vacuum line that goes to the brake cylinder on the bulkhead (I forget its name), and it came back clear. Then, I moved the air intake unit to the area after the air filter to see if there was a problem. To my surprise, I discovered an oil leak that I had never noticed before. It was discovered that the leak was caused by loose screws on the rocker cover. After I snugged them all, I did a smoke test once more, and the leakage stopped. My question now is whether smoke should have been present there initially. I can't recall why smoke from the air intake pipe would wind up in the rocker cover; it's been so long since I played the game. After tightening the screws, I put the car through its paces on the road, but it still goes into limp mode when I apply too much boost pressure or rev too quickly.

Has anyone ever smoke-tested anything before, so I'm not sure if there are certain points to test or if I should use a variety of pipes. Would be eternally grateful for any assistance.
 

[stevenkeyte]

After doing smoke tests and vacuum tests at various locations throughout the system this evening, I'm relieved to report that everything is in working order. Similarly, I'm relieved to report that no leaks were identified in the air intake system. Changing the boost pressure sensor is the next thing I'll attempt.

Can somebody tell me if trying to smoke the exhaust system was worth it? I'm at a loss as to what to do when neither the engine light nor the fault code can provide any guidance.

[MotoGravity]

Tell me which scanner you're using.

It is possible that a code in another system is causing the problem; a comprehensive scan could reveal it.


For instance, there was no problem with the engine, yet the automobile went limp.
The exhaust flap problem code was actually located in a subsystem, not the engine.
The engine turned off after I removed this code.

The problem persisted despite the exhaust flap replacement, proving that a code recorded elsewhere had an effect on the engine management system.

[stevenkeyte]

The only thing I've been doing is utilising a BT OBD2 scanner with an iPhone app. Wasn't looking to spend any more money, but I suppose the more costly ones read more control units.

Since this whole ordeal started, the water temperature has been quite unpredictable, and I still don't know why; if anyone has any insight into this, I'd greatly appreciate it. Fortunately, it now appears to run better, and the engine temperature indicator is less erratic. the current state of the issue posting is simply limp. After 18 months, if you remedy this, I could even begin to enjoy her! 😄

[stevenkeyte]

No saved codes; I just hooked up a plug-in scanner (Autolink Autel AL519) that my company uses for the vehicles.

On the other hand, I did notice that the MAP sensor measurement never budged from its ideal 100.0 kPa. It was stable throughout the tests, unlike the others.

After looking it up online, the MAF sensor read 7.87 g/s, which looks a bit high.

Does anyone think they could comply if asked? In any case, I might end up switching them out. Disqualify them.