2001 Grand Prix GT RPM's at 65 MPH

My 2001 Grand Prix GT runs at 3000 rpm's at 65 MPH is that normal it seems high to me. It is shift into all 4 gears normally and does not seem to be slipping. Just wondering what rpm's other Grand Prix owner have at 65 MPH.

Not sure what mine are at but I'm almost positive it's not even at 2k at 65. I do have a GTP tho and I think the gears are different so my post probably isn't relevant.

Hate to say it, but 3k for 65mph is WAY too high. I'll bet your getting terrible MPG.

Are you sure its going into 4th? It's either not going into 4th or TCC isn't locking up.

Bring it somewhere and have it scanned for trans codes (either a dealership or a trans shop)

4t65e's will run almost exactly at 2K at 70mph (or at least all the ones I have driven have).

When was the last trans service done? And what type (flush, pan drop)?

My 2001 Grand Prix GT runs at 3000 rpm's at 65 MPH is that normal it seems high to me.

On issues such as this it would help to post your mileage and when the last tranny service was performed, if any.

Also, I noticed you have two posts on this issue at Chevrolet Tahoe. They have been deleted.

Taching 3000 rpms at 65 mph for a GP GT is abnormal. I agree it sounds like the torque converter clutch (TCC) is not locking which it should do after shifting to 4th - OD and at speeds above 45 mph.

Also note that extreme cold weather conditions will affect when the car shifts to 4th and TCC lockup. What are your weather conditions?

It has been cold here 0-5 degrees but I have a heated garage. The car has 120,000 miles on it and the fluid was change 25,000 miles ago. No service lights are on but the gas mileage is down. Is this (TCC) easy to fix like a soleniod or speed sensor switch?

It really doesn't make any difference if you have a heated garage. The ATF fluid has to come up to proper operating temperature and the temperature fluid sensor (TFT) senses it is correct along with other operating parameters.

If the TCC is not locking then gas mileage will suffer. The TCC lock/unlock is controlled by a TCC-PWM solenoid located under the tranny side cover. Not exactly an easy DIY job. See pic below. It wouldn't hurt to get it scanned with a trans capable scanner and/or one capable of reading GM extended DTCs. Note: Some of these tranny DTCs do not set the SES/CEL light.


http://i5.photobucket.com/albums/y186/lizzywiz/valvebody2.jpg
4T65E EPC- Pressure Control Solenoid (PCS)

Thanks for the information I just drove into my office and it took a while to shift into 4th gear but on the highway it must not lockout at 75 MPH 3500 Rpms. Well it looks like a trip to the trans shop is next. My son uses this car for college he is only on the highway to come home would it hurt the trans to leave it this way since most of his drive is in town at 30-50 MPH? Oh the fluid looks clean and does not smell burnt.

Someone told me this weeked that a sensor may not be telling the trans to shift into lockout any ideas what that might be?

There are several sensors used both engine and transaxle but hard to speculate which one it would be without further diagnostics. Hopefully a scan with a trans capable scanner/scan tool reveals something.

Also, certain tranny DTCs when set will disable 4th - OD and shift adapts.

My 2001 Grand Prix GT runs at 3000 rpm's at 65 MPH is that normal it seems high to me. I had this exact problem with my 2001 GP GT with about the same mileage as yours. No knowing what the problem was and how costly to get it fix, I traded in my car for $3000 toward a new Impala GT this June...

I am very much interested in knowing what your fix will be.

Had the car scanned today found a P1811 Maximum adapt and long shift code they want to rebuild the trans. I am thinking of trying a trans flush first any thoughts?

Be careful on a trans flush. The P1811 DTC is a line pressure issue and in most cases the PCS solenoid or shift timing being out of tolerance when checked by the PCM module. A total tranny rebuild is not required.

However, review the following thread at our Tips & Maintenance forum first which covers the P1811 DTC:

http://www.automotiveforums.com/vbulletin/showthread.php?t=920671

Thanks for all the great information I changed my fluid and filter today but first I ran the seafoam trans tune in it for a couple days. The fluid that came out was dirty just like the pictures on the link you supplied. I did not install a shift kit they did not sell any at the local Auto Zone or I would have done that right away as well. Now the car shifts alot better but I still have the RPM problem but I did not get the code cleared and I found some info that said when the code is set the PCM freezes shift adapts so now I'm going to get the DTC cleared with any luck I might have solved the problem. Changing the PCS would be something that the trans shop would have to do and that would cost at least $650 and that was a quote from the Trans Shop. Any other ideas or feed back?

Thanks for all the great information I changed my fluid and filter today but first I ran the seafoam trans tune in it for a couple days. The fluid that came out was dirty just like the pictures on the link you supplied. I did not install a shift kit they did not sell any at the local Auto Zone or I would have done that right away as well. Now the car shifts alot better but I still have the RPM problem but I did not get the code cleared and I found some info that said when the code is set the PCM freezes shift adapts so now I'm going to get the DTC cleared with any luck I might have solved the problem. Changing the PCS would be something that the trans shop would have to do and that would cost at least $650 and that was a quote from the Trans Shop. Any other ideas or feed back?

The DTC should be cleared because not only will it disable shift adapts but also may inhibit 4th gear and TCC operation.

You can do the shift kit at a later time but it would not be a bad idea to install it. The kits are available from our specialty Grand Prix parts and performance suppliers like ZZPerformance.

As a matter of fact I just received this message quoted below on Dec 30 in reference to the thread at Tips & Maintenance. Most members that have applied the mod had success resolving their issues.



Just wanted to thank you so much for the suggestion of using the ZZP shift kit to eliminate the harsh shifts from the 4t65e transmission! I put in the shift kit, Dexron VI and filter change today on my wife's '04 Buick Century. It started getting hard shifts at about 60,000 miles as soon as warmed up, especially in stop-and-go driving. The tranny fluid was flushed (not pan drop and drain) at dealer's suggestion @ 32,000 miles, and I thought I was staying ahead of things. But at 60,000, the gremlins showed up anyway! So far the tranny's working like new. We couldn't justify $800 to replace the PCS, especially after seeing your (and other peoples') experience with the problem coming back soon after replacement. What a great solution you had with the shift kit! Thank you so much,

Todays update I had the DTC cleared today but it did not help my RPM problem 3000 RPM @ 65 MPH i'm going to drive it for a few days and have it scanned again. It shifts into 4th gear you can clearly count the shifts at 40MPH its running 2000 RPM and as you increase speed the RPM's climb. When you punch it there is no shutter like its slipping it just goes.

Are you sure 4th (OD) gear is even engaging? In order for me to rev 3000 rpm @ 65 mph I have to keep it in 3rd gear which will obviously inhibit TCC lockup on top of that. In that scenario I see around 2500 rpms by keeping it in D3.

I wonder if you have a mechanical issue like a bad 4th clutch shaft which is common where the splines strip due to poor material. Not hardened.

I just tried driving in 3 instead of D. It shifts 3 times which would be 4th gear when in 3 does that make sense? That last shift it drops 500 RPM but if I shift into 2 it drop way down push it up to three and it shifts twice. Something doesn't seem right.

I'm pretty sure your missing 4th 3K @65 is 3rd gear. the double shift you see/fell is 3rd then TCC engagement.

That makes sense, does this mean trans rebuild time.

Hello,

I am encountering the same problem with my 2001 Chevy Monte Carlo SS. I am running at about 3250rpm at 74mph. My GM Tech 2 says it is in 4th gear, but when I shift it down to 3rd gear there is no change. I noticed the TFT sensor readings are way off. My transmission should be running at about the same temp as the engine and probably higher. I drove the car over 10 miles tonight while monitoring the TFT with the Tech 2 and the temperature never exceeded 150 deg f. I also noticed the TCC only operated at about 24%. I am going to check out the wiring going to the transmission, if that is ok then I will drop the pan and check the wiring and if that is ok I will replace the TFT sensor and go from there. I will post my findings.

Rich

Hello,

I am encountering the same problem with my 2001 Chevy Monte Carlo SS. I am running at about 3250rpm at 74mph. My GM Tech 2 says it is in 4th gear, but when I shift it down to 3rd gear there is no change. I noticed the TFT sensor readings are way off. My transmission should be running at about the same temp as the engine and probably higher. I drove the car over 10 miles tonight while monitoring the TFT with the Tech 2 and the temperature never exceeded 150 deg f. I also noticed the TCC only operated at about 24%. I am going to check out the wiring going to the transmission, if that is ok then I will drop the pan and check the wiring and if that is ok I will replace the TFT sensor and go from there. I will post my findings.

Rich

Obviously it is missing 4th - OD. Sometimes 4th gear engagement will be affected by the weather conditions. How cold is it in your area? And no transmission oil cooler installed?

Drop what pan? You are aware the TFT sensor and the solenoids are under the side cover assembly (driver's side) so it is a bigger job. Just want to make sure you realize that.

Just curious if anyone was able to determine the cause of this problem, my 1999 grand prix just started doing the exact same thing!

I have a 2001 pontiac grand prix and my car is experiencing the same problem. I am getting really bad gas mileage. My check engine light is on because of the EGR. Could this be contribute to the problem?

60 mph is near 2000 rpm in 4th gear with TCC applied.
I assume you miss 4th gear and TCC......and probably the cruise control is inoperative too.
Most probable cause: failed throttle position sensor.
Veryfy this link... www.avigex.ca/xport/dtc21.jpg .(DTC# is from OBD1 but same with OBD2 #P0122/123/124)
Of course reading the codes would confirm.

I never fixed mine it still running with only 3 gears. The engine runs great I just never spent the $1000+ to replace the trans. I use the car in the city most of the time now. It's been over 4 years now.

Ljc77, you are jumping into an old thread......should start your own.....

Experiencing the same problem?

Exactly what is your problem? State all if more than one......

Does your car shift into all 4 gears? Does the TCC engage? What are your rpms at 60mph on the highway?

Is the EGR setting the only code? If yes, what is that code number? If not, what are the other codes?

You say your gas mileage is bad......approx. what is the MPG? What was it previously?

Pull the vac line off of the fuel pressure regulator......seeing/smelling fuel in the vac line?