2000 3800 Pontiac Grand Prix woes...

**rschap1** · 06-01-2009, 03:24 AM

Wife's GT (not sc'ed) has a few issues. I have gotten the best advice here before, so I am back. I'll start with the service engine soon light. Scan showed fuel EVAP system troubles. Replaced gas cap and it became intermitten rather than a full time light. Back to full time now. I have done a pretty good check of the lines all the way from the gas tank, EVAP can in rear quarter, up to the engine. No obvious leaks or breaks or anything. Anyone know of a common problem here for these vehicles? Car was also diagnosed at the dealer of "wide gap shift points" (or something close to that). Their "trans" mechanic said solenoid packs need replacing. Just under a grand and dropping the front end out to get at 'em. With 133k miles on it, I thought I'd try replacing fluid and filter first. Did that and it seemed a lil' better. Then Googled the part numbers and anything I could find, and decided to add 1/2 a can of SeaFoam Trans Tune as I had read alot of good results from this. A little different feeling now. Previously it felt like a sluggish shift from 1-2 and 2-3, now it shifts HARD. Not quite a SLAM but close. From stop, or between gears. Any remedy besides new solenoids? Third and last question...driver's side rear has a clunk that I can't locate. VERY similar to when the passenger side had a tore up "lateral alignment link". Local Belle Tire guys destroyed the threads on that trying to align the rear. All stripped out, the link would give a real solid clunk when hitting ruts and bumps. EVERYTHING I look at seems tight as can be. Swung around like a jungle gym on everything I could grab hold of under there....? APPRECIATE any input or ideas. AGAIN THANKS!!

**cammed goat** · 06-01-2009, 03:42 AM

Drivers side rear could be a bearing or strut mount. I have heard stories about the upper and lower intake manifold gaskets going south on the 3800s as well. Check those.

**GTP231** · 06-02-2009, 08:38 PM

99+2000 model years have a tsb on the pressure control solenoid. Ususally when that goes bad you get a harsh shift similar to what you are describing. The EVAP code I can't think of anything common for these. See if you can find a shop or a buddy with access to a smoke machine and use that to find the leak. Heck the solenoid could be going or one of the vacuum elbows are drying out. The rear like goat said could be the strut mount or maybe one of the lateral link bushings are bad

**rschap1** · 06-03-2009, 02:25 AM

The dealer scanned it and said it showed an 1118 error code for the trans. Just under a grand to replace the needed solenoid. Local trans shopped ranged from half that to just over that, but all said upgrades should be done then too. What's the "tsb"? Also wondering what the "smoke machine" is? Isee a valve on the EVAP lines on top of the intake area, I assume a mechanic can pressurize the system with smoke, see where it escapes and fix? First time I had heard of that, but makes sense. The rear I thought would be easy to find. Just don't see anything loose, and having a hard time duplicating it w/o driving over some big bumps. THANKS very much for the input. It sure helps!

**GTP231** · 06-03-2009, 05:09 AM

I forget the TSB number and yeah at 130K I'm sure the trans could use some work. Yes the smoke machine does exactly what you think it does. Greatest thing in the world for finding leaks

**rschap1** · 06-19-2009, 06:00 AM

Well after hearing every possible diagnosis and getting estimates from $200-$2000 for the trans problem, I had a new solenoid installed for $450 and that seems OK so far. Code still shows for EVAP trouble, and I haven't been able to track that down. Have to find a place w/smoke machine. BUT, the trans guy said he showed a MAF error too. The EVAP turn the Check engine light on and off intermittenly. He said that I need a MAF and pigtail. Also not related to trans, or EVAP errors. First I had heard of this trouble. So now I am still trying to track the suspension clunk which Belle tire says may be sway bar link OR strut mount...EVAP trouble, MAF sensor possibly, AND hopefully the trans is fixed. Any further words of wisdow? A good place to order a MAF and connector or a cheaper fix? THANKS AGAIN!!!!!

**GTP231** · 06-19-2009, 06:11 AM

gmpartsdirect.com usually has good prices

**1MileCrash** · 06-19-2009, 09:34 AM

you won't need to drop the entire engine to get to the shift solenoids. there should be two solenoids and both are in the valve body. i'm fairly certain that on the 4t65-e transaxle that you can simply remove the drivers side cv axle and then remove the valve body cover and access the shift solenoids right from there.

let me give you a website where a lot of guys mod the gps and the montes with the engine and trans that you are talking about. someone over there should be able to help you.

www.mymonte.com

**rschap1** · 06-22-2009, 09:16 AM

Thanks for that too! Everything I saw and have read, did say the tranny either needed to get dropped, or part of the frame/craddle could be removed. Looking at it myself, I saw less than a couple inches between the side cover and the frame. The cover itself looked to be about twice that deep. Dealer and the trans shop said solenoids were under that cover too. Spent $450 on having that replaced. Seemed to have fixed everything in the trans. Now told the MAF needs replace, along with the mystery EVAP leak, and rer suspension clunk...
VERY MUCH APPRECIATE all the help. Heading to the Monte site to do some more searchin' THANSK AGAIN!!

**rschap1** · 07-07-2009, 04:20 AM

Well the $450 solenoid replacment seems to have taken care of the transmission troubles for the wife's GP. So far so good anyways. Check engine light hasn't came on since. The trans shop said codes showed the MAF sensor needed replacing and it was running on the MAP sensor. But it has been running good, no check engine light in a long time either. ?? But after looking and looking and swing around on the rear suspension like it's a jungle gym, I still can't pinpoint the clunk. Thinking I may try and drop the strut out and replace the top mount. I have taken a big pry bar and gently wiggled the large washernut on top the strut from inside the trunk. Didn't seem any worse than the passenger side or the fronts. Could not get any noise from it. But it is my only/best guess right now. Wondering if there are any tips, tricks to make this easier. Planing on starting to WD40 up the lower mount hardware for a few days, remove that, the 3 top mount nuts, and should be free right??? I know nothing is ever as easy as it looks (for me anyways), so i thought I would ask. THANSK AGAIN for all the help and advice here!!

**rschap1** · 08-05-2009, 04:52 AM

Well getting closer to getting all of the wife's GP troubles fixed. The $450 tranny solenoid seems to have taken care of that, a new strut mount in the rear fixed the clunk. $40 at Autozone and about an hour. Just had to squeeze like heck to get it all back together (no compressor). She said it stumbled pretty bad the other day. Scanned and it shows a MAF sensor error. She was told it will run on the MAP sensor in this event. I checked and cleaned the connnection to the MAF, shot some contact cleaner through the honeycomb at it...Anything to try or do prior to $175 sensor replace. Car drives fine, no light on dash...just get told that it shows the code. Sound right? Anywhere to get a deal on the part? Know what size tamper proof torx I need right off? THANKS BIG again!!