This is for my mom's stupid car. It's a 97 Kia Sephia and here's the problem. It's a 5-speed and the car doesn't want to seem to go about 55 mph. At 55, the engine sounds like the rpms are real high(there's no tach) but it still feels like it's 7000 rpms or something crazy, plus it's been eating a lot of gas since it started doing this. What could cause this, it seems that the car will blow up if you try to make it go any faster. IT's only got 51,000 miles on it too. Can anyone help?

 

I'm not a genious about cars but maybe she lost a cylinder (Or two?) That I think would explain the Sephia not wanting to go that fast and the higher rpms problem. I think that because the engine is working harder from running the high rpms all the time it would eat more gas. Might want to get a second opinion on this though. Like I said, I'm no genious.

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V6 Bone Stock

 

Sounds to me like a driveline problem. Is the clutch engaging fine through all of the gears? It may be slipping and causing the higher rpm's(hence the bad fuel economy). Let's go through a list here. Because she'll rev up quite high, I don't think it's a fuel delivery, air, or spark problem. I could be wrong though. Does the car idle fine? Are you having any other problems with the car? Have there been any modifications to the car? Any more information that you can share would be helpful.

 

From the information given, I would place my bets on the clutch. Sure sounds like it's shot. This has happened to my Jeep a few times. I could rev the engine freely while it was in gear. Even in 5th gear you could make the engine redline without affecting speed the slightest bit.

Try this - set the parking brake, put the car in 1st gear, rev the engine up a bit, and release the clutch. A good clutch will fight the parking brake and try to move the vehicle. A bad clutch will 'bite' a little bit but won't feel like it will move the car.

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'88 IROC 305 TPI
Crappy 700R4 slushbox
Gutted airboxes
180 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel (gotta luv it)
Ram-air setup coming soon
Flowmaster muffler (puke)
Taylor SpiroPro wires
Accel cap and rotor
Ported plenum
Kills: '94 Z28, Olds Aurora V8, bunch of Mustangs, T-birds, ricers, and others who assumed a 12 year-old car would be too slow.

 

Exhaust plugged?

 

Not the exhaust! That would bog it down with bucking and a sensitive pedal (OK as light throttle, bucks and dies when you floor it.)

Of course a whattizit? 1 3/4" exhaust is considered a restriction!

 

The car seems to shift fine 1st all the way through fifth. I could be wrong though.

 

Don't those things have a 100,000 mile warranty on them? I don't know if the 97's do or not but I would take it to the dealership and let them check it out.

 

I"m betting on the clutch, a person I know had a 99' sephia and had to replace the clutchon it three times until they bought it back.