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Amedee, Pontiac Technician
Category: Pontiac
Satisfied Customers: 26639
Experience:  ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
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My 2003 grand am keeps jumping rpms and puffing smoke out tail pipe/

Resolved Question:

my 2003 grand am keeps jumping rpms and puffing smoke out tail pipe/
Submitted: 6 years ago.
Category: Pontiac
Expert:  Amedee replied 6 years ago.

What color is the smoke? Blue black or white?

Are there any codes in the computer?

What size engine do you have?
Customer: replied 6 years ago.
smoke is greyish white, no codes on computer and my engine is 2.2 4 cyl
Expert:  Amedee replied 6 years ago.
I would check the fuel pressure regulator. It is located on the fuel rail. It is round, about a quarter size and has a vacuum line going to it. If the regulator is leaking gas than it can cause this problem. Pull off the vacuum line that goes to the regulator. Be absolutely sure there is no gas in the vacuum line. If there is, the diaphram has ruptured and there is gas entering the engine that is not accounted for and the regulator will need to be replaced!
Customer: replied 6 years ago.

my engine is a 2.2 ecotec and does not have a vaccum operated fuel pressure regulator, I mean there is no vaccum line going to it.

Expert:  Amedee replied 6 years ago.

Another common cause for a stalling condition is the ignition switch. THey go bad on these vehicles all of the time causing this type of problem. I would definitely check this out too before going any further.
Customer: replied 6 years ago.
I am not stalling, I will be driving on freeway running about 70mph and rpm's will go from about 2200 to about 3000 and stay for a second and back down, also when I am at a traffic light and sitting there then take off my car puffs smoke from tail pipe, it doesn't do it constantly, just after sitting idle for a few min.
Expert:  Amedee replied 6 years ago.
Got it!

You might have an air or a vacuum leak. This is very common! Open the hood and listen for a hissing sound when the engine is running.
Unmetered air can enter the engine through a vacuum leak, a dirty airflow sensor that is not reading airflow accurately, an EGR valve is not closing and is leaking exhaust into the intake manifold, an EGR valve that is allowing too much flow.
If it is hard to pinpoint take some brake cleaner or starting fluid around the intake manifold and vacuum lines and see if the engine stumbles or if the idle is affected. Be extremely careful when doing this!

Also, your throttle body may be carboned up and need to be cleaned! This can cause all sorts of idle and hesitation problems. This is caused by the throttle plate not seating properly. The First thing i would do is clean out the throttle body with some throttle plate and intake cleaner and a small brush. Another common cause would be the Idle Air Control motor. This is very common on older cars. The IAC motor gets lazy and cant keep up with the fast idle changes. Also when the IAC motor is out, I rec to check the passages for carbon build up. If they are plugged they need to be cleaned out.

Possible Causes
Check for air leaks in the Air Induction system (e.g., in the intake manifold)
Check for air leaks in the PCV system and in its related hoses and/or valve
Idle air inlet passage or throttle bore is dirty or full of deposits
IAC valve has failed
MAF sensor is dirty, "skewed" or installed improperly
Throttle plate, throttle shaft or linkage is damaged or sticking
TP sensor is out-of-range or "skewed" high

Customer: replied 6 years ago.

so are these possible problems for just rpm jumping or also for smoke out of tail pipe?

Expert:  Amedee replied 6 years ago.
YES.. also, be sure you are not bruning any oil or coolant.
Customer: replied 6 years ago.
I am burning oil. I was 2 quarts low since 3 weeks ago. could the 2 problems ( the rpms and smoke from tail pipe be related)?
Expert:  Amedee replied 6 years ago.
IT is possible.. maybe a bad PCV valve... if not.. then the problem would be the motor itself... either the rings or the valve or valve seals..
Customer: replied 6 years ago.
does my motor have a pcv valve, because my brother looked at it and said he didnt think it has a pcv valve?
Expert:  Amedee replied 6 years ago.
YES.. on the valve cover...
Customer: replied 6 years ago.

could you mean under the valve cover, there is not an external pcv valve? There is hose going from intake to valve cover about 6 inches long, no valve at valve cover


Expert:  Amedee replied 6 years ago.
That is correct... everything is under the valve cover.... except for the hose and the air intake boot or plastic cover that the hose goes to..
Customer: replied 6 years ago.

one more question, could the pcv valve also cause it to run slightly hot when sitting at traffic light as well, because I have noticed that when sitting at traffic it runs just barely hot and then when I take off then comes the puff of smoke out of the tail pipe?


Expert:  Amedee replied 6 years ago.
NO.. the PCV valve will not do this... but if you are burning coolant.. it will do this...
Customer: replied 6 years ago.

and the pcv valve would be causing me to burn coolant?


Expert:  Amedee replied 6 years ago.
No.. that has nothing to do with coolant...

Customer: replied 6 years ago.
ok, i'm not losing coolant, i just thought they may be all related since all happening at same time, it's not running real hot just barely over half way on temperature gauge
Expert:  Amedee replied 6 years ago.
Do you have heat inside the vehicle when this is happening?

Have you checked the coolant level?
Customer: replied 6 years ago.

um not real sure, I know that when I am sitting in school traffic waiting to pick up my children I notice the temp gauge rises a couple of notches, but if i cut the air on it doesn't do it


Expert:  Amedee replied 6 years ago.
What do you mean air? Are you talking about the AC?
Customer: replied 6 years ago.
yes sry.
Expert:  Amedee replied 6 years ago.
Ok. this is because the fan just comes on when you turn the AC on. This is most likley keeping the engine temp down when you come to a stop. I do not think this is a problem.. all cars do this...
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