Jump to content

Guest RedCutlassSL

Recommended Posts

Guest RedCutlassSL

For those of you with the 3100, what is your RPM at when you are going 70? Mine is hovering around 3000, and that seems high, I can't remember what it was before I had those problems with my transmission last week. Thanks

Link to comment
Share on other sites

Hey my sister's 96 GP with 3100 does about 2000 in overdrive at 70. Your tranny may not be going into overdrive. I know my 3.1L will do 3000 at 70mph if it is not in overdrive when the torque converter is locked in for better gas mileage. But to me, it sounds like your not in overdrive, maybe a sensor or linkage problem, not real sure though.

Link to comment
Share on other sites

My 3100 also is about 2000 at 75MPH.

 

BTW....this is really stupid, but how do you know when the Tourqe Converter locks up? And simply, what happenes? Is it something manually changed, or computer/mechanicly controled.

 

Jon

Link to comment
Share on other sites

The torque converter locks up in 3rd gear. You can usually feel it, it feels like it is shifting into another gear. In normal acceleration it locks up just before going into overdrive. In an automatic, the actual flywheels, I guess, are turned by the fluid surrounding them, they never touch. Like the engine tuns a disk that turns fluid that turns the TC that inturn turns the tranny. When the TC locks up, the two disks actually intertwine and touch and become one unit, they lock up. So, the fluid is not turning the TC the engine is directly. This saves on gas mileage mainly.

Link to comment
Share on other sites

So i just want to be clear on this TC question posted above. I've never been to sure on this either... So my 90 Euro is a 3 speed automatic (PRND21). Is 3rd gear "D" considered overdrive? Or when it TC locks up is this considered overdrive? I does feel like another shift when this happens. And BTW my car does cruise at 2800-3000 around 70mph and around 2100 at 55mph.

 

Also one more question, didnt want to create a whole new post for this: What is a Plenum? I see you guys talking about it all the time but have not been able to figure out what it is, thanks.

Link to comment
Share on other sites

Yeah, on your gear selector, you have 1,2,D and a D with a circle around it right?? Just plain D is 3rd gear and in third gear the TC locks up. Then after that, you go into over drive, or the D with the circle around it that actually is an "O" for Overdrive. So, you have only four gears, 1st 2nd, 3rd and Overdrive. But, it will feel like you have 5 gears, b/c of the TC locking up. When it locks up it keeps the same ratio as your third gear, 1.00:1., its just more fuel efficient. If you have any other ?s feel free to ask.

Link to comment
Share on other sites

Sorry for the second post but, I missed what you meant by "PRND21" Anyway, yeah your "D" should be your overdrive. You have the 4T60 tranny, right?? Check on your tranny pan to check. That is what I have and in overdrive you should be around 2000 at 70mph, that is where mine runs. And if I am in third and the TC is locked up, I run about 2800-3000 at 70mph, it still sounds like your not in overdrive......But I don't know how to fix that....have you changed your tranny fluid in a while and have you done a torque flush on it, b/c just dropping the pan changing fluid and filter only changes about 50% of your fluid, the torque flush fluses the fluid in the TC and both of those will change ALL MOST all of the fluid. Hope this helps.

Link to comment
Share on other sites

Sorry for a third post but I did some research, on Trans-Go's website.

 

-cmo1234

 

I did some research and found that you either have a 3T40 or a 4T60. If you have the 3T40, which is a 3 Speed, I assume that your 2800-3000 rpms at 70mph is right, if you have the 4T60, then it is wrong. The 3T40 has the following gear ratios, 1st is 2.84:1, 2nd is 1.600:1 and 3rd is 1.00:1 with no fourth obviously. Now, my 4 speed turns 3000rpm in 3rd which is 1.00:1 like yours at 70mph, so if you have the 3T40, then that is correct, this info should help you more, then what I said above.

Link to comment
Share on other sites

i would just like to correct myself. my car does about 2250 at 80-85mph in OD. it seems that if you do have OD, then your car just isnt using it, and you should have that tranny looked at.

Link to comment
Share on other sites

Everybody,

Thanks for all the info. I believe I have the 3 speed 3T40 (or 125C according to the specs on the main pages of this site). I'll take a look at what the tranny pans says if anything. Also my selector on the car on has only one D on it, no overdrive D w/the circle around it. So I guess my RPMs are ok and the fluid is nice and rosy red, almost as red as my interior, lol.

 

BTW got some 18% tints all the way around this past Thursday, pretty sweet, they keep out that hot ass FL sun. Next comes a new coat of paint to cover up the cracking paint (Oh Oh, better get Macco), and then some GTS light covers front and back. All this depends on how the $$$ situation is within the next few months.

Link to comment
Share on other sites

wait, it sounds like you're sayin when u put it in D (without the circle around it) that's when the TC locks up and saves u gas...it's the other way, the D with the circle aorund it is more fuel efficient

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...