Skip the auto shop - Our mechanics make house calls

Q: cracked exhaust manifold pipes/headercar will not go fast revs high but No speed ?Cause?

asked by on

car will not go past 30 miles an hour engine revs high with no speed increase No power on acceleration while taking off it takes a long time to get up to 20 mph like the engine is struggling. help please 2003 hyundai elantra gls auto 4cl 2.0l

My car has 151000 miles.
My car has an automatic transmission.

A: In order of priority, if you have a cracked...

In order of priority, if you have a cracked exhaust manifold (leaking carbon monoxide), that actually has to be fixed first or at least coincident with the repair(s) to the engine/transmission. The principal danger from exhaust leaks (carbon monoxide) is NOT death from acute exposure but rather long term tissue damage from chronic low level exposure. Way more people die from chronic, day to day CO exposure than from the kind of acute exposure you read about in the newspaper. So, basically, so as not to damage your health be sure to get the exhaust leak fixed at the same time the acceleration is resolved.

If your vehicle won't go over 30 miles per hour, it is possible the PCM has forced the transmission to operate in limp mode. Forced limp mode operation can occur if, as an example, there is a fault with the input and output speed sensors on the transmission, or the kickdown switch. There are probably downloadable OBD-II trouble codes that will help the Mechanic hone in on the trouble area. You might try checking the transmission fluid level and condition. If the fluid level is low and/or burnt, that might be related to the problem. To rule limp mode in or out (without a code scanner) sometimes you can disconnect the negative battery cable for a 1 minute to reset the PCM and then see if the transmission shifts normally until it enters limp mode again. There are other possibilities for what you are describing though including faults in the fuel, ignition, air induction systems, and even the possibility of a severely restricted exhaust system. What I would suggest is diagnose the engine/transmission issue first, but again, once that is restored, the car is unsafe (unhealthy) to drive unless and until the exhaust leak is also repaired. Please let us know how we can best assist you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: What does the automatic transaxle shift indicator mean?

The automatic transaxle shift indicator is located on your instrument panel. This indicator illuminates when the automatic transaxle shift position has been selected.

Q: Right turn signal doesn't flash - 2003 Dodge Sprinter 3500

You'll need to turn the signal on and go around to check all the exterior lights to see exactly which one is out. When one goes out, it will stop blinking like you are describing, or it will do the...

Q: Exhaust smell

It sounds like one of two problems: an exhaust leak or a faulty catalytic converter. Inspect the exhaust system for rust or holes. If you see a hole, a qualified muffler shop should be able to weld in a new...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.