2001 Pontiac Grand Am Misfire issue?

Question

I have a 2001 Pontiac Grand Am 2.4 SE. I took my car to Pep boys because when I turn my AC on and pull out and about to take off the idle drop and I push the gas some times the car stalls or feel like it lost power and when im at a light the car idle will drop to 500rpms. It misfire in till I take off then it start driving okay its just when im at a stop light or just started the car and about to take off or when im on the freeway and I slow down to 25 mph then try to take it back to 60 mph and you really feel it misfire but after that it drives fine. Anyway the guy said the car misfires under load 2 cylinders. He said I needed a new engine but didn't do no compression test or anything but hes said he did a chemical test on the coolant and he said it failed. But the thing is My car don't lose coolant or have coolant in oil or oil in coolant. No smoking. but it do get to 230 temp sometimes if it really hot outside. I change the spark plugs and wires and fuel filter about three months ago. The car runs good besides the misfire. What would caues 2 cylinders to misfire?

Answer 1

The coil needs to be replaced. It only cost $45 at Autozone and do it yourself!

Answer 2

I DON'T KNOW, but I suppose if your car has individual cylinder coils (spark coils, one for each cylinder), MAY BE that at low speeds the spark isn't receiving a fire signal as it should. At this point I have to wonder about your injectors, O2 sensor, cam or crank position sensors.



Normally when you turn on the AC the engine idle speed should come up to compensate for the parasitic drag caused by the AC Compressor. Some cars use a solenoid to open a valve and change the Manifold Air Pressure, causing the engine idle to increase. Other cars use the computer to control an "Idle Air Control Valve". When the engine idle drops (for whatever reason) the IAC valve opens slightly to increase the amount of air flow into the engine, thus, picking the idle back up to around 800 RPM. It's possible that IAC valve is malfunctioning.



A friend of mine has a SAAB and its IAC valve was stuck, and it was stuck in a low idle condition. So she couldn't turn the AC on until the car was moving or she would stall out. When we replaced it the car had to go through a learning process - that's where the car remembers certain parameters and adjusts to meet the particular driving habits of the owner. Weird but true. When we replaced it the engine remembered being at a low idle condition. When she took off the IAC valve would open (as it remembered trying to do in the past) to compensate. The result was a scary ride where the car was accelerating on its own.



Fortunately being a standard transmission, she was able to press the clutch and the brake pedal to regain control of the car. She brought it right back to me. We had to run the car for several minutes simulating different driving conditions until the computer began managing the IAC valve properly.



I say that just as a word of caution. Previous experiences has taught me that this could become an issue, so just be aware IF you have an IAC valve problem.



Good luck.



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THUMBS UP MIKE. Pep Boys doesn't employ top mechanics they employ high school kids who are looking for experience. They HAVE a few good mechanics but in general they are to be avoided unless you just need an oil change and a lube. Speaking of "Lube" jobs, they sure gave my wife a "Lube" job when she asked to have her brake lines flushed with new brake fluid. Cost her $89.00. I could have done it for a couple bucks, but she listened to one of her friends.



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Answer 3

Get a second opinion, or even a third. Don't go to Pep Boys again.

Get the second opinion from a local garage. Find one close to your home and watch it's parking lot for overnight vehicles and see how fast they move out.

Note how many cars get taken to this shop, you know find an honest shop with a good mechanic. You'll not find that a Pep Boys, or any of the other big chain, crank 'em out, change parts and inflate the work places.



Good luck.

Answer 4

I don't know, however I think if your vehicle has man or woman cylinder coils (spark coils, one for every cylinder), is also that at low speeds the spark is not receiving a hearth signal because it should. At this point I ought to marvel about your injectors, O2 sensor, cam or crank function sensors. Most often while you turn on the AC the engine idle pace should come up to make amends for the parasitic drag prompted by means of the AC Compressor. Some automobiles use a solenoid to open a valve and change the Manifold Air stress, causing the engine idle to increase. Other automobiles use the pc to manage an "Idle Air control Valve". When the engine idle drops (for anything cause) the IAC valve opens rather to develop the quantity of air go with the flow into the engine, for that reason, making a choice on the idle again as much as round 800 RPM. It's viable that IAC valve is malfunctioning. A buddy of mine has a SAAB and its IAC valve was caught, and it used to be stuck in a low idle condition. So she could not turn the AC on except the auto used to be moving or she would stall out. When we replaced it the auto needed to go by means of a finding out method - that's the place the automobile remembers targeted parameters and adjusts to meet the specific using habits of the proprietor. Bizarre but real. After we replaced it the engine remembered being at a low idle situation. When she took off the IAC valve would open (as it remembered looking to do up to now) to compensate. The influence was once a frightening experience the place the car was accelerating on its possess. Happily being a typical transmission, she was competent to press the grab and the brake pedal to regain control of the automobile. She brought it proper back to me. We had to run the auto for a few minutes simulating extraordinary using stipulations except the pc started out managing the IAC valve accurately. I say that simply as a phrase of caution. Earlier experiences has taught me that this could become an problem, so just be aware when you've got an IAC valve drawback. Excellent success. ") THUMBS UP MIKE. Pep Boys doesn't employ top mechanics they rent high college kids who're looking for experience. They've a couple of excellent mechanics but as a rule they are to be kept away from except you just want an oil alternate and a lube. Speakme of "Lube" jobs, they certain gave my wife a "Lube" job when she requested to have her brake strains flushed with new brake fluid. Cost her $89.00. I could have completed it for a couple bucks, but she listened to one in every of her acquaintances. "/