QuestionMy car runs perfect for like 15 mins from a cold start. Then while driving the transmission starts to act up. Runs high rpms at a stop. Sometimes acts like its gonna shut off then the car saves itself. Finally sometimes taking off from a stop the car will sputter for a sec or two then take off. What could this maybe be?
AnswerHi, Paul. Not only are there several possibilities, but it sounds like you may have multiple problems as well. If I had to pick one component that could cause all the above issues, I'd choose the throttle position sensor (TPS). But I also cannot feel the problems myself, so I have difficulty assessing the probability that the TPS is the issue. The engine performance issues could be caused by a vacuum leak, misfire, or EGR issue.
With all that is occurring, I'd be very surprised if there were no trouble codes stored. So the first thing I'd recommend is to retrieve all trouble codes from the engine and transmission control modules. These will likely be your largest indicator of what the problem may be. If you follow-up and report back with the trouble codes, I can better advise you on what to check and how to check it, or in some cases, even where the problem is likely to lie.
In addition, if you can, describe the problem with the transmission's behavior. The symptoms you give seem related to engine performance, so I have little understanding what the transmission issue is.
And lastly, let me know which engine you have in your Santa Fe (2.7L V6 or 2.4L 4-cylinder). With this information, I'll know the fuel management system with which your vehicle is equipped and will better be able to identify likely problems.
