2004 Grand Prix Knocking and stalling

BANKS1850

MEMBER
2004 PONTIAC GRAND PRIX

Hi, my automatic GP GT has 74K miles on it and I am having 2 issues that have recently begun to worsen. The first issue is that it will knock when accelerating. It only knocks under medium and low acceleration, mashing the pedal eliminates the knock, after 1-3 seconds the knock goes away and won't return until the pedal is release and depressed again.
My second issue (this has started in the last few weeks), is my car will stall the first time it is started unless gas is given. Once gas is given for just a moment, it is fine, idles fine once started.
Any help would be great. I am ok with bringing it to my mechanic, but I would like to go in with some "ammo" so I don't get fleeced. Thank you.

1 Reply

TBDK

MEMBER
24 POSTS

The knocking could be a few things. Can you tell if it's coming from the top or bottom of the motor? An easy way to tell is take a length of pipe, preferably metal, and place 1 end to the valve covers while the car is running. Put your ear to the other and and see if it sounds close. Do the same to the oil pan area. BE CAREFUL NOT TO HIT OR GET HIT BY ANYTHING. STAY CLEAR OF THE FAN EVEN IF IT'S OFF. With the motor on it can start at any time. If it's the top it could just be a lifter. If it's the bottom it could be a rod. A lifter is alot cheaper to replace then tryin to fix a rod knock. Has the oil been changed regularly? Do you "beat on" your car or race it anything like that? A 2004 probably wont have a rod knock but thats not saying it can't. About the stalling, I would check andmake sure the injectors are clean and that gas pressure is good. Also check the timing. That could also make it stall.
Hope this helped.