1997 Buick Century 4t65-e no first gear

cw41

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#1
Make
buick
Model
century
Year
1997
Miles
87000
Engine
3.1
My buick will not shift into first gear, It seems like from a dead stop, especially when engine is cool it starts off in second gear. when fully warmed up you can manually shift from third to second but will not downshift manually into first. Its time for a filter and dex 6 fluid change I had this done for my mom 3yrs ago and the filter was supposed to be changed but?? I see there is a solonoid that might be sticking is this accessable with the pan off or in the bell housing? also see a shift solonoid on the throttle body? thank you for any help. the fluid is still red and no smell of burning or discoloring. thanks
 

grcauto

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#2
The solenoids are behind the cover on the side of the transaxle. Not a real easy job but doesn't require special tools. Is reverse working OK?
 

cw41

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#3
The solenoids are behind the cover on the side of the transaxle. Not a real easy job but doesn't require special tools. Is reverse working OK?
Yes reverse seems to work just fine. I decided to drop the pan as it is time for a filter and fluid change, found no excessive debris in the pan normal to me. Used a wix quality filter and dex 6 fluid and now I have first gear but it dont want to shift out of it without letting of the gas. I had a dodge tranny that did the same thing I think it was a valve body issue??
I see a solonoid with two plugs that is bolted to the top of transaxle next to the firewall. Is this some sort of shift solonoid? thanks
 

grcauto

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#4
Through bottle of BG trans fix into it. That stuff is real good at helping the valves in the VB.
 

cw41

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#5
I put a bottle of sea foam conditioner in it and still every other time from a dead stop will stick in low and have to let off the pedal to upshift??
 

cw41

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#6
At first, I couldnt get it to go into low gear to drive up my ramps. I had to shift to low 1 and then I had first gear to drive up ramps. I need another hoist!! Now it wont shift out of first manually or automaticlly unless you let up on the pedal then it moves to second and to OD. No codes of any kind, i tried to make it set a code by having the issue happen within a couple of minutes but no code was set?? thanks for any ideas.
 

billr

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#8
Are you using live-data to check all the sensors, verify what gear is actually "selected" vs "commanded", line pressure, turbine speed, things like that? Have you disconnected one of the trans cables (or pulled a trans fuse) to verify you can read trans codes?

As I read it, the fluid/filter change was 3 years ago, nothing recent; is that correct? If you do a fluid change now, I would stick with Dex3, avoid anything that is specifically Dex6 (there are some "universal Dex/Mercon" that are OK). That's just my personal opinion, I can explain further if anybody wants me to.

I think "Lube Gard Red" is also a worthwhile "Hail Mary" play if you can't find the BG stuff.
 

cw41

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#9
thanks billr, I appreciate your input. Too bad I put dex 6 back in it. My understanding GM went to this synthetic because of sticking valves like what I have now. I dont have a shop scanner so I have to play by ear and when you place in OD, 3,2 or 1 from a stop, cold or warmed up it will stay in low until you let off the pedal. You can get to 35mph in low and I dont have my tach hooked up but I assume 3000 rpm+ and still wont shift. No codes stored no ck eng lite ever. I do appreciate your input on the dex 3 as I have some. getting hard to find though. Yes you are correct that my mom had this car serviced at a dealer and they hopefully changed the filter as I provided it to them. I cannot remember on what tranny fluid they used?? thank you, chuck
 
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#10
I think "Lube Gard Red" is also a worthwhile "Hail Mary" play if you can't find the BG stuff.
I agree on the Lube Gard Red and I believe that is the product that bp042665 ( who runs a trans shop) usually recommends here. I have never used the BG products and they may be just as good or better, I am not knowlegable about that.
 

billr

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#11
Remember "Transman"? He was the one I learned from about the Lube Gard. I have another 10 years and 80k miles on my 4L60E with the P1870 and Lube Gard in it. No telling if the LG is the only reason, but I'm taking no chances, I add it every time things get iffy.
 

cw41

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#12
I remember him, i just ordered a bottle of lube gard red I try that hope it will unstick what is stuck!! thanks for the tip.
 

grcauto

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#13
I remember him, i just ordered a bottle of lube gard red I try that hope it will unstick what is stuck!! thanks for the tip.
Lube gard is good. I put it in the same class as BG. They both do well at freeing up sticky valves. If it don't work the bore the valve moves in may have ovaled a bit and would need to be serviced or replace the VB.
 

cw41

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#14
I think this tranny is a 4t65-e w/3.1 v6. It looks like the cover can be removed to replace the valves/solonoids. The case gasket is 45.00 I think at rockauto! Wow! gold plated? I'll try the lubegard first hope it buys some time. 22 yrs old but 80,000 miles I know the age has something to do with it.
 

grcauto

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#15
I think this tranny is a 4t65-e w/3.1 v6. It looks like the cover can be removed to replace the valves/solonoids. The case gasket is 45.00 I think at rockauto! Wow! gold plated? I'll try the lubegard first hope it buys some time. 22 yrs old but 80,000 miles I know the age has something to do with it.
With that few miles I doubt the valve bore is out of round. Could be but I think the additive will fix you up.