2000 Pontiac Grand Am Hard vibration and banging after sta

GRANDAM03

MEMBER
2000 PONTIAC GRAND AM

Shakes or Wobbles problem
2000 Pontiac Grand Am 4 cyl Front Wheel Drive Automatic

I have a 2000 pontiac grand am and when you start the car it begins to vibrate extremely hard and makes rapid clunking noises as if a hunk of metal was inside the engine. When I drive it, if you are soft on the gas pedal you can get the car to run close to normal, and once in a while it seems to drive and accelerate fine. I have replaced plugs, plug boots, coil packs, coil pack housing, fuel filter, and tested fuel pressure and still have same problem. Could injectors cause this problem or does it sound more serious? The engine seems to run solid otherwise.

6 Replies

WRENCHTECH

MECHANIC
20,758 POSTS

Do you have a check engine light coming on at all?
Can you pinpoint just where the noise is originating?

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Tuesday, August 17th, 2010 AT 4:27 PM

GRANDAM03

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The check engine light comes on and goes off, it will even flash at times and throw the traction contol off, the sound seems like it is coming from the front side of the motor, when put on one of the pocket testers it says random cylinder misfire

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Tuesday, August 17th, 2010 AT 4:32 PM

WRENCHTECH

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This is where you have to start.

The "check engine" light is an indicator for a system that monitors many electronic functions in the system, also called the "malfunction indicator lamp" (MIL). It can come on for any of hundreds of different causes from any of the systems that the computer monitors. Some are very important and can lead to further component or engine damage and some are emissions related not as serious but still a problem and need to be repaired.

Your first step is to have the computer scanned to retrieve the trouble codes that were set when the check engine light came on. Those codes will give you specific information about what the computer saw and will get you pointed in the right direction to find your problem. With a 1996 or newer and some 95 cars and you have an AutoZone or Advanced auto parts in your area, they will read them for free. Once you have these code numbers, we can be a lot more specific about what your problem may be.

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Tuesday, August 17th, 2010 AT 4:44 PM

GRANDAM03

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Ok I found the codes that I received from auto zones testors, the first one is
P0300-Cylinder misfire detected, random cylinders;
P0442- EVAP, evap emmision system/ small leak, no flow condition.
I also replaced the fuel cap because of second one in case I was lucky to get easy fix on second but no luck.

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Wednesday, August 18th, 2010 AT 8:51 AM

WRENCHTECH

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The PO300 is the one associated with your problem. It just means there is a random misfire condition. That really doesn't help us too much in finding the problem. I suggest you let a shop listen to it and at least give you some kind of idea what is taking place there.