: Drivability issue, hesitates under 2,000 RPM



GREGB1954
08-04-12, 09:33 PM
My 2006 N* started having low power if I am in 5th gear going around 30-40 mph. While at that speed if I give if about 25% more throttle the engine seems to have almost no power. If I press the accelerator enough to force the transmission to downshift and the RPM's get over 2,000 it drives fine. There are no trouble codes captured. I took it to a dealer and they said it was fine (probably because they put a scanner on it and there were not codes thrown).

I know it use to feel stronger in these conditions, and my son noticed it too.

Any thoughts? I checked the intake manifold bolts and they are tightened to spec.

Thx in advance.

STS-4000
08-04-12, 11:20 PM
Only thing I can think to do is to try the "PROCESS OF ELIMINATION" which means start by replacing from the cheapest on up to the expensive parts that can cause problems that are relevant to yours, like spark plugs, air filter, mass air flow sensor, etc. Or try cleaning your mass air flow sensor and see if that helps.

STS-AIM
08-04-12, 11:49 PM
I have this issue also. 2006 STS 4.6 V8, 75,000 miles. It is random. Mostly when you first drive in the day. Tried injector cleaner, different grades of gas and the only thing that works is to use the manual shifter.

Hope this helps. Anyone have other suggestions.

curtc
08-05-12, 12:26 AM
Check oil level, could be the VVT system not working correctly due to low oil.

DarkMingBlueSTS
08-05-12, 01:08 AM
Mine does that too same speeds and all but I only have a 3.6...idk for sure but I'm thinking it's my torque converter

MacMuse
08-05-12, 08:39 AM
Sounds normal to me. It's 5th gear, and that's a very slow speed. That's the prime time for 4th gear, 3rd if you're in a real hurry.

I've spent the last few months really working the manual shifter. My purpose was to evaluate mileage impact of never (well, almost never) letting RPMs climb over 2,000. One result I noticed is that 5th gear is useless at low revs/speeds like under 40mph. I also noticed about a 2-3 MPG improvement by staying under 2,200 in all gears. Definitely makes me slowest off the line until I can get it into 4th.

But I will say a recent trans fluid service (100K service) made a noticeable improvement in high gear operation at low revs.

Mullah88
08-05-12, 06:07 PM
same thing is happening to my 06 sts v6