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.

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?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. cracked exhaust manifold pipes/headercar will not go fast revs high but No speed ?Cause?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Front tires screeching when turning

Hi, it sounds like the wheel bearing is starting to wear out on the right side. When you turn left all of the weight of the car is shifted to the opposite side which is extra stress then on the...

Q: my car is hesitant to accelerate when changing down to second gear uphill and sometimes it just won't accelerate.

Hi there. What were the diagnostic results? What were the data readings from the ECM? What diagnostic process did you use to determine the other parts were in need of replacement? These are the questions that I ask anytime I...

Q: Will my 2010 Ford F150 benefit from a performance exhaust?

Warped manifolds are a well known problem on the 5.4L engine. My personal F150 has a noticeable exhaust leak from the manifolds on cold start, but goes away once the engine warms up and the manifolds expand. As for adding...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...