Mechanics

PONTIAC GRAND PRIX GAS PROBLEM

2008 Pontiac Grand Prix • 78,000 miles

5.3 litre V8 Got an oil change and a tranny flush. I was told the trans fluid looked pretty good. After about 2000 or 2500 miles I noticed what I would describe as a hesitation at 50 mph, I would actually watch my rpm's jump around +/- 200 or 300 rpm. It was really only when I would maintain that speed or let up slightly, and only at 50. If I would give it a little gas it would be fine and also at any other speed. I put fuel system cleaner and engine cleaner in after an oil change, it was called Z max. I had 3/4 of a tank of gas I went through most of that and have noticed no change. Oh and I think it only does it after 10 or 15 minutes of driving. After adding Zmax now I have noticed a wine coming from the engine sounding kind of like you get from the power steering but its all th time. Also when the car is cold there is a hesitation now in 1st gear or low rpm ( I only noticed this to happen once or twice in the last couple days) When I drive the car every thing seems to be ok when I give it a little gas it shifts fine and downshifts fine so im wondering where I should start? Maybe the fuel system, tune up, ? Thank You
AD
Avatar
Triplerush
November 12, 2012.




Have fuel pressure checked. You may have an issue with the torque converter in the trans, you need this verified by a trans shop to be sure.

Stay away from additives, they are gimmics that do very little if anything at all.

Roy

ASEMaster6371
Nov 12, 2012.


AD