PontiacBonnevilleClub.com

Hey guys--

Did't get any response on the GP forums so I thought I'd come home and post here. I'm confused on where to post--I like it here but don't have a Bonneville anymore!

Anyways, the new 2001 Grand Prix GTP Coupe (55K miles). If I accelerate normally, I feel a minor shudder on the 1-2 shift about 30% of the time. If I accelerate harder (nowhere near WOT however), no shudder and the shift is very positive. Fluid level is right on the money. I actually have a two-month engine/transmission warranty that will be up in 10 days so I figured I'd ask if it was anything major. I know a 9-year old car isn't going to be perfect.

Your thoughts? TCC? Motor mount?

Thanks!

What kind of plug wires does it have? I know that my bad Taylor wires are causing that same issue right now...

Original wires from '01. It sure doesn't feel like an engine miss. Definitely feels like it's transmission-related. Perhaps not?

Engine troubles can seem like tranny issues. Make sure everything on this list is up-to-date, and see if the troubles go away.

Brand Suggestions are in the parentheses.

• 1987-2005 Bonneville / Buick 3800 Maintenance List
  
  Run Seafoam through gasoline and intake every 5,000 miles. One pint of Seafoam in a half tank of fuel is a good mix. The intake is optional, but recommended.
  
  Grease: Ball Joints, Tie Rods Every 8-10k ( recommended) [b]Air Filter[/b] [i]Every 15k[/i] [s ... Amsoil EaA, Purolator PureONE)[/size]
  PCV Valve Every 30k
  MAF Sensor Element Cleaning/TB Cleaning Every 50k viewtopic.php?f=48&t=1661
  Fuel Filter Every 15-25k (Purolator, AC Delco, WIX)
  Spark Plugs Every 30-50k (NGK TR55 or Autolite 605) (Never Bosch)
  Ignition Wires Every 30-50k (Napa Belden, AC Delco, Autolite Pro, NGK) (Never Taylor or Bosch)
  Oil & Filter Every 5-6k or Every 6 months (Mobil1 or Amsoil)(Mobil1, Purolator PureONE, Amsoil EaO or WIX) (Never Fram) viewtopic.php?f=45&t=214
  *Conventional Oil Every 3k/3 months(Pennzoil with a WIX (Napa), Delco or Purolator filter)
  Transmission Flush Every 15-20k (Always make sure filter is changed when flushed)
  Cooling System Flush Every 25-50k or Annually (Peak or Prestone Green Coolant Only) (Never Dexcool)
  Oxygen Sensor Every 80-100k (30k for non-heated) (AC Delco or Denso) (Absolutely never Bosch) viewtopic.php?f=48&t=794
  Accessory Belt Inspect every 15k, replace every 100k, or as needed
  Cabin Air Filter Inspect and Replace every 15k, or as needed in dusty conditions. (Note: 00+ Only)
  Evap Core Cleaning Whenever Needed (Note: 99 and older only) viewtopic.php?f=45&t=2432
  
  *Special Considerations*
  All 3800s, LG3, LN3, L27, L36, L26, L67 & L32, especially important on vehicles factory installed with orange Havoline Dexcool Antifreeze/Coolant: http://www.dex-cool.net/
  Lower Intake Manifold Gasket Replacement, every 80-100k (ignorance of this can allow coolant to enter your engine oil, this happening can cause irreversible lower engine damage, requiring replacement of subject engine)
  
  Series II, Naturally Aspirated, RPO:L36:
  Upper Intake Manifold Plenum Replacement, Every 80-100k (ignorance of this can allow coolant to enter your intake manifold, possible damage to occur can be hydrolock, irreversible damage to emissions devices, misfires, etc. Most times, engine replacement is required if ignored long enough.) viewtopic.php?f=53&t=1061
  
  Series I, II, III RPO Code L67 & L32:
  Change Supercharger Oil; Every 30-50k. (Intense Racing or GM Dealer) viewtopic.php?f=56&t=1690
  Supercharger Belt (Series II and III only); Inspect Every 15k, Replace Every 100k or as needed.
  
  Rev. 6/7/09 By 00Beast

If the fluid hasn't been changed lately, try that first. These transmissions have a rather sloppy 1-2 shift to begin with, to try and make it less noticeable. Worn fluid could make it worse.

I had something similar. I tried ruling out all the engine related shudders. Eventually the shudder got worse and worse until I either had to drive it hard or manually shift the lower gears to hold them longer to get above the range where it would shudder. I even tried a new vacuum modulator. The behavior changed but really didn't get any better. Suddenly one day it would barely go into gear. It was rebuild time.

PCS? TCC?

Thats a classic symptom of a failing pressure control solenoid. I have replaced a great deal of these solenoids for this very reason. One thing to check first is the mass air flow sensor. If it is dirty, it can effect shifting.

If shifting improves with a MAF cleaning, that does not mean the PCS is OK. It is probably still the weak link that made the problem noticable. After cleaning the MAF, the PCM may register more air flow and command the PCS to higher pressure. This will make the shifts firmer and mask a "first sign" failing PCS.

If you still have a warranty remaining, I would bring it to the dealer and tell them everything you told us and suggest that it may be a failing PCS "because you had a different pontiac that did that" and see what they say.

If they replace it, I would THEN clean the MAF sensor.

***Also, another huge thing I forgot to mention. The transmission has a nice whine to it which from what I'm reading is PCS-related***

The car has been dropped off at my local Pontiac dealer. My concern is that it is so faint and doesn't happen all the time that they will dismiss the problem. I'm tuned into it and can sense it pretty easily. I made sure he wrote down possible failing PCS on the ticket for the mechanic to see, shudder on 1-2 shift, whine. The car has to be warm with light throttle applied to feel it. Heading up an incline helps as well.

I was able to fix my PCS Issues by installing a mild shift kit

Half way down page 2 is where I installed my shift kit...
http://www.pontiacbonnevilleclub.com/fo ... 1&start=20

Sounds good. Let us know what happens.

Diagnosis:

#06-07-30-023B: 4T65E Transmission 1-2 Shift Shudder at Light to Moderate Acceleration (Replace Complete Second Clutch Assembly) - (Jan 12, 2007)

I've already contacted the dealer where I bought it with a warranty still intact but I have my doubts that they are going to own up and pay it. Very pricey.

Why wouldn't they pay?

They have agreed to pay so I'm quite pleased. I can have the work done locally as well. They're only going to pay what they could do it for at their service shop but it's only a couple of hundred bucks cheaper so I'm more than happy to pay the difference instead of driving the car five hours for them to repair. It's refreshing to see a dealer willing to work with you to make things right instead of creating a huge hassle for you so you'll just drop the whole thing and forget about it. They've earned my repeat business.