Bought a 2012 subaru legacy used with approximately 59000 miles. Ran fine for about a week. Now it regularly stalls at quick stops. If I am able to slowly approach a stop it is fine, but at times I have had to stop quickly and it always stalls. I have had it in to a Subaru Dealership. They have changed the oil, which was dirty and performed a fuel induction service, which seems to be just part of the 60000 mile service. Stalling continues. I had a 10 year old Chrysler minivan that ran better than this thing…very Frustrated. Suggestions?
Does it loose all power, lights etc? Does the battery move around or is it held down properly. Try cleaning the IAC idle air controller.
There are MANY reasons this could be happening. I will try to cover the Foremost causes that I see and repair all the time.
You mentioned an induction service? This is good…IF it was done… The procedure is simple…remove the air snorkel pipe going to your engine…its easy to do… Then take a rag with carb cleaner spray and clean the intake Butterfly valve…also open the valve and clean where this valve Seats itself… Spray the carb spray onto the rag otherwise it just evaps as fast as you spray it…the rag allows the chemical to melt away any carbon that may be clogging things up for you.
What is your idle speed on this engine? When the engine is warm take note of the RPM’s…hopefully you have a tachometer. Note the RPM when cold…when hot…and also when hot while in drive with your foot on the brake. It should be about 800-950 RPM’s.
If it is a lot lower than this…you may need to adjust the Air Screw on the throttle valve assembly…the same one you cleaned above…There should be a large looking Flathead screw SOMEWHERE on that valve…it may also have a rubber plug covering it so you cannot see it…but it should be there somewhere… Turn the screw OUT…to RAISE the RPM’s.
There is also the MAF sensor…located between the Throttle Body and the Air Cleaner box…it will be and electrical sensor in the rubber air tubing going between the throttle body and Airbox. You can unplug and remove this sensor… Once removed spray the sensor end with the carb spray…DO NOT TRY TO TOUCH this end with anything. Think of the buisness end of this sensor like the filament of a lightbulb…they can get dirty and need cleaning with a carb or MAF sensor spray cleaner to clean off any debris or dust from the tip of this sensor.
Next…and actually FIRST…LOL…Look at your Air Cleaner element…Is it dirty? You need to remove the element and look at the other side…where the Air enters the vehicle…you will more than likely be looking at the clean side when you remove the Air box lid…so take it all the way out to see the other side.
ALL of these items can help you… You may only need one or two to handle this situation. A little feedback from you will help me help you actually. So get under your hood or give this suggestions to someone who will carry them out. I repair situations like this VERY OFTEN…and the solution to your issue more than likely resides in my suggestions…let us know what you see so I or we can guide you further. This is a common and EASY issue to correct. It could be as simple as turning your Air Idle screw out a half turn or so…These screws VERY OFTEN need adjustment between the time the engine is manufactured…till the time it gets FULLY broken in…the air requirement very often changes (becomes larger) to maintain a proper RPM level to prevent stalling.
If this is powertrain related you have 1000 mile warranty left to use. Make sure they documented the poor running/stalling condition at a dealer on a bill so you can latter collect on warrranty past 60k!
The induction service and dirty oil sounds like a place without mechanical skill since neither would fix this. Your vehicle needs no service it needs a repair then focus on service.
My sheer guess and this would be covered by powertrain is your transmission torque convertor is not unlocking at quick stops fast enough stalling your engine. Make sure to get this looked at again! I think this car has CVT in this year, my parents 2015 does.
Your torque converter might not be unlocking quickly enough here.