Volvo T5 Throttle Issues Cause Rough Starts & High Fuel Use

Having some experience with engine throttle issues, I dealt with almost identical symptoms on my T6 2.1 last winter. The symptoms you describe match what I experienced, inconsistent throttle response, rough starts, and increased fuel consumption. After initial attempts at throttle cleaning did not resolve the issue, my workshop diagnosed a defective accelerator pedal module. The throttle valve was functioning correctly, but the pedal module was sending incorrect signals to the engine control unit. The repair involved replacing the complete pedal module assembly, costing 205€ including diagnostics. Since the fix, the engine response has been smooth, fuel consumption returned to normal, and cold starts are no longer an issue. The car throttle control is now perfectly responsive. Before suggesting specific solutions, it would help to know: What is your current mileage? Have you noticed any warning lights? When was the last throttle cleaning service? Does the check engine light come on intermittently? Are the symptoms worse in any specific weather conditions? These details would help determine if your issue is similar to what I experienced or if it might be related to other throttle control components.

Our mileage is quite close, mine just hit 130992km at the last service. Throttle cleaning actually solved my rough start issues completely. The mechanic showed me the carbon buildup on the throttle body before cleaning, it was pretty bad. After a proper throttle body service and control valve inspection, fuel consumption dropped back to normal levels. The total cost was 180€ for the complete throttle cleaning procedure. Much cheaper than replacing the whole throttle body unit. Just make sure they use proper throttle cleaning solutions and not just regular engine cleaner. Since the service, the engine throttle response is spot on and cold starts are perfect. Worth checking this first before looking at more expensive repairs.

Good to hear the throttle cleaning resolved your issues. My experience matches yours exactly, I also noticed a dramatic improvement after the throttle body service on my T6 2.1. The carbon buildup seems common around that mileage point. After the cleaning, my engine idle stabilized completely and fuel efficiency improved by about 15%. My mechanic also suggested making throttle cleaning part of regular maintenance every 60000km to prevent future issues. One additional tip: since the service, I've been using high-quality fuel and changed my driving habits slightly, letting the engine idle for 30 seconds after cold starts. This has helped maintain the clean throttle position sensor and prevented new carbon deposits from forming as quickly. The 180€ you paid sounds right in line with what these services typically cost. Much better than the 800€+ a new throttle body would have set you back. Regular throttle cleaning maintenance definitely helps avoid those bigger repair bills down the road.

Thanks for confirming the throttle cleaning fixed the issue. The carbon buildup shown by the mechanic explains the rough starts and high fuel consumption. A thorough air intake and throttle body service was definitely the right call. The 180€ spent on throttle cleaning was worth every cent compared to replacing parts unnecessarily. The stable engine idle and improved throttle position control prove it was the root cause. Regular maintenance should prevent similar issues in the future. The advice about warming up the engine and using quality fuel makes sense for preventing carbon deposits. Will add throttle cleaning to the maintenance schedule at 60000km intervals. Much better to prevent problems than wait for symptoms to develop. Good to know others faced similar throttle valve issues around this mileage. The mechanic mentioned many vehicles need this service but owners often overlook it until performance issues appear. Having a clean throttle body really makes a noticeable difference in how the engine runs.