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lukassteel1

Alfa MiTo Turbo Sensor Issue Causing Power Loss

Hi all, my car has been acting up lately and after a bad experience with my last mechanic, I want to get some other opinions. The engine feels sluggish with reduced power, and there is a whistling sound plus hissing during acceleration. The check engine light is on. The error code points to an issue with the charge air temperature sensor. Has anyone dealt with similar symptoms? I am driving a 2018 Alfa Romeo MiTo diesel with 128467 KM. What would be a reasonable repair cost and how complex is this fix typically? Looking for advice on whether I should try a different mechanic or if this is something that needs dealer attention.

4 comment(s)

liam_nacht1

Last month I dealt with similar symptoms in my 2015 Alfa Romeo Giulietta diesel. The airflow sensor and air temperature readings were inconsistent, causing similar performance issues. The main problem was indeed the charge air temperature sensor, but it was actually the wiring harness connection that had degraded. These automotive sensors are sensitive to poor connections, and the whistling usually indicates an air intake leak somewhere in the system. The temperature gauge readings were also erratic before the fix. This is not a major repair but requires precise diagnostic work to avoid replacing parts unnecessarily. A competent independent mechanic with proper diagnostic tools can handle this, no need for dealer service. The fix involved cleaning the connector pins, replacing the damaged wiring section, and testing the air intake system for leaks. The repair is straightforward for someone who knows these engines well. Total labor time was about 2 hours. Just ensure the shop has experience with Alfa Romeo engine management systems, as the diagnostic procedure is specific to these models. Worth noting: If left unaddressed, faulty temperature readings can cause the engine to run rich and potentially damage other components over time.

lukassteel1 (Author)

Thanks for sharing that experience. I had exactly this happen with my 2017 MiTo last winter. The charge sensor was giving false readings and the air temperature values were all over the place. The mechanic found a corroded connection that was causing the temperature gauge to act up. Did you remember the total cost for your repair? After my fix, I also noticed the air intake system needed a good cleaning, which improved performance even more. Has everything been running smoothly since your repair was done?

liam_nacht1

Since having the repair done, my Giulietta has been running perfectly. The total cost came to 95 Euro to fix the faulty cable and plug connection for the charge air temperature sensor. This included cleaning the connector pins and testing the system. A proper diagnostic showed it was just the connection causing issues, not the sensor itself which would have been much more expensive to replace. The temperature readings are now stable and consistent, and the engine is performing as it should with no more warning lights. The automotive sensor system is quite sensitive to connection issues, but once properly fixed, these problems typically dont return. The air intake and temperature sensor setup on these models is actually quite reliable when all connections are sound.

lukassteel1 (Author)

I went ahead and got my MiTo fixed last week. Just wanted to update that the charge sensor wiring repair cost me 120 Euro, which seems fair considering the diagnostic work needed. The air temperature readings are now stable and that annoying whistling sound is completely gone. My mechanic discovered the air intake system was quite dirty, so I paid an extra 45 Euro to have that cleaned too. The engine response is much better now. What really impressed me was how quickly they identified the corroded connection causing the temperature gauge problems. The whole job took about 2.5 hours, and they showed me the damaged wiring that was causing all the trouble. Sure beats the previous shop that wanted to replace the entire sensor assembly for 400 Euro. No more check engine light, and the car pulls strong again. Definitely glad I asked here first and found a more competent mechanic who knew what to look for in these sensor systems.

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