2003 Dodge Neon car is making a funny noise

LADYDUNLAP

MEMBER
2003 DODGE NEON
V8
4WD
AUTOMATIC
113,000 MILES

2003 dodge neon 113000 miles. My engine light came on. When I drive, I hear this noise in my car that sounds like a "thump thump" in the car and it worsens when I go to 50mph. After that it makes the car shake along with the steering wheel. I noise is loud and only gets louder as I accelerate. Took it to auto zone was misfire. I have a mechanic who fixes cars well, as long as he knows what the problem is. Can you tell me whats wrong so he can fix it for less money? Thanks

1 Reply

MORTICAR

MEMBER
46 POSTS

You may have two seperate problems occuring at the same time. First I will offer this for the engine light and misfire. There are a few things which can cause the misfire some cheaper than others but here we go.
#1 Improper or damaged spark plugs.
#2 Fuel injection system faulty
#3 EGR valve not funtioning properly
#4 Vacuum leak
#5 Problem with the engine control system (expensive)

These are a few good places to start looking.

The other noise problem sounds more like a bad tire that could have seperated causing the tire to become out of round making the noise and the shaking of the car. It could also be tire balance but most likely you have a bad tire. The shaking could possibly be causing the engine to make a false diagnosis of misfire due to the sensor being shaken so violently causeing it to misread the virbration.
My first choice would be to get the tires checked out first then reset the computer by disconnecting the batt for ten minutes and then redrive the car and see if the problem comes back (this is just if there is a bad tire). If it comes back after checking the tires with no problem then look into the other items I have listed.
Hope this helps!MORT