High RPM's and little acceleration

2008 HYUNDAI ACCENT
90,000 MILES • 1.6L • 4 CYL • 2WD • AUTOMATIC
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BEARCAT4242
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I just recently bought vehicle listed above GLS used. It has a clean background. The last 3 months have been very frustrating. After only a month I felt like I was asking more of the engine to reach normal driving speeds (30 / 40 mph). The RPM's were slowly climbing higher over time to where acceleration from a stop often peaked at 2.5k. There are other odd anomalies that seemingly appeared with the problem. Such as the car itself feeling heavier, steering wheel feeling tighter after a mile of driving, braking to a stop is sudden and inconsistent, and the RPM's drop to nearly idle power (1,000) when I'm driving short distances. I've relayed all of these symptoms to my family and 2 different auto shops, yet all I receive is a look of confusion as if I'm imagining these issues. I went to one of those said auto shops for a pricey diagnosis and the only thing that came up in their report was an open thermostat. I reluctantly payed for the repair. It drove mildly better but the high RPM's are still present. Just the other day I was on the interstate going 75 at 4,000 RPM's. The engine was loud and I couldn't keep up with I-35 traffic. I don't know if it's just a terrible vehicle or if there are a number of underlying problems that could be to blame.

Appreciate any feedback.
Oct 15, 2019 at 11:07 AM
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STEVE W.
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Welcome to 2CarPros. Your description sounds like transmission problems. The first thing I would do is check the transmission fluid level and condition and color. You should have red fluid with no real small other than oil and no grit or metallic glitter. The next step would be to check that your brakes are not dragging, the description of the brakes acting strange and the higher rpm needed and required to move the car could be a symptom of that.
A quick way to test that would be to take it for a short drive and coast to a stop and then use a non-contact thermometer to measure the hub areas and see what they are reading.
Ideally they will only be a few degrees warmer than the outside air temperature.
Oct 15, 2019 at 8:59 PM
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BEARCAT4242
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Thank you for the quick reply, and trying to address the issues vague as they are. I agree, I'm starting to think the transmission is wearing out. The brakes yes they could absolutely be replaced too. Is there anything else that could be impeding the engine's ability to run efficiently and over work itself? (Major or minor)

Also, should I be concerned with this? I think it's coolant not sure if it's leaking though. I recently just got an open thermostat repair so the mechanic drained and refilled new coolant. Maybe it's just spilled coolant? Not sure
Oct 16, 2019 at 12:47 PM
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STEVE W.
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It looks like spilled coolant, easy way to tell would be to rinse it away and see if it comes back. I would try replacing the fluid as a first step in the transmission however I'm leaning more toward a brake issue. After you drive it do you notice any hot brake smells or feel heat at any of the wheels? That would be a big clue and why I suggest checking the temperature of the brakes. You could have a bad master cylinder or line that is blocking fluid return and as the vehicle is driven the fluid heats up and applies the brakes enough to slow you down.
Oct 16, 2019 at 3:02 PM
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BEARCAT4242
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New update: I took it to the same shop that repaired the thermostat today in case it wasn't spilled coolant. It was indeed a "faulty gasket". However, a new issue has come up today. It's taking longer to turn over and now the car is revving itself up to 2.5k RPM when it does turn over and sits there until it slowly drops down to normal idle range. Is this a vacuum leak? Or possibly sensor issue? I checked the brakes after I drove but there wasn't any heat resonating off them, just a bit warm to the touch. I did smell a bitter sweet burnt odor coming from the hood and have been told by others that it "smells hot". You could be right about something heating up and negatively affecting other components because it seems to drive well enough for a minute or two until it starts the sluggish process all over again.
Oct 17, 2019 at 3:58 PM
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STEVE W.
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Hmm. Sweet burnt odor is usually coolant. That could simply be from the leak getting onto other things as it gets misted around by the under hood airflow. Sounds like it isn't the brakes. Here is a quick test to see if it's more likely engine and transmission or chassis related. Get the car up to speed on flat level road (55 or so) and wait until it's sluggish. Now shift into neutral and let off the throttle. Don't touch the brakes. What does the car do? Ideally it will coast and slowly lose speed. That would point at it being engine or transmission related. If it slows down fast or when you shift into neutral it seems like you stepped on the brakes it is more likely something chassis related.
Oct 17, 2019 at 4:49 PM