transmission fluid is dark but doesnt smell?

I'm no expert but changing the fluid would be a good start. Have a mechanic do it.

Well, you're correct about the smell part with regard to the tranny fluid. The dark color generally means it has aged ...gets a little oxidized like brake fluid ...and it's time to change it.

It would be helpful if you could define "shifting funny" ...is it slipping, hard shifting ....

But first the basics: is the fluid at the correct level?

To check the transmission fluid level correctly, the tranny needs to be at normal operating temperature, the engine running, the vehicle on level ground and the transmission in whatever gear (Park or Drive) it says on the dipstick. If the tranny needs to be in "Drive" then make sure to *fully* apply the parking brake and put a chock or two under the wheels. If the level is not up to snuff ....like nothing is showing on the dipstick ...then this may be the cause of your problem. If so, try adding some fluid to bring it up to the correct level. Do this carefully as overfilling a transmission can be just as bad as not having enough fluid. With the fluid level up to snuff, see what happens. If your problems are resolved then press on with the fluid change.

Now, that may not be your problem. Generally, changing your fluid is not going to fix your tranny if there is something internally worn or out of adjustment.

And if the filter in the transmission is so plugged as to create problems with restricting the flow of fluid, then definitely you have something internally wrong with the transmission.

A couple of options here.

If you have a shop you trust, and you have been doing business with for awhile, you might touch bases with them first with regard to your transmissions shifting problems. Transmissions are fairly complicated and usually require specialized service techs to diagnose/work on them. Your shop may only be able to offer the fluid/filter change options and not much else. Problem is, if it is internal and it does need to be torn into, then your tranny fluid flush will be mostly wasted money. You could try it ... have them replace the filter and flush the fluid (these are two separate services so you'll be charged accordingly) and see what happens ...but if you do need some internal work a good portion of the fluid will be need to be replaced along, possibly, with a new filter. So you'd be wasting some money and time.

OR ...

Bring it into the dealership and have them run a diagnostic on it in the hopes there are some computer trouble codes locked in the system to help pinpoint the causes of your shift problems. You can also have the tranny serviced (fluid and filter) while it is there. Most dealerships have recognized their competition from the indie shops and are competitive in pricing. Plus, with the number of Chinese-made aftermarket parts flooding the market (like as could be installed at an indie shop), you will at least be assured you'll have OEM-quality GM parts used in the repair of you car. You will also get the correct Dexron VI fluid (vs some "universal" stuff) in your transmission.

Me, I would first check the fluid level and if all is okay then I would give the dealership the nod for further diagnostics. And do avoid the "transmission-fix-in-a-bottle" secret elixir which is guaranteed to fix your tranny like new while improving your love life at the same time. But you seem saavy enough not to fall for that stuff ;-)

You are BRILLIANT for not using DEXCOOL in your engine. Go to BING and type in DEXCOOL to discover that 40 million GM engines have been reported damaged over time from DEXCOOL coolant. You are BEST off by using Mercedes Benz YELLOW coolant, or Audi ROSE coolant in there!!! You do NOT need a new transmissions. THe darker color is telling your that the friction of coefficient and viscosity properties of your fluid are breaking down. Perhaps even a quicky lube has topped your fluid with the WRONG stuff, which is quite easy to have done. I would either go to a genuine GM dealership if you can find any left) and have them flush and fill your fluid using a new gasket and filter. ALSO, it is possible to wash down the VALVE BODY of the trans with Brake Cleaner spray to remove excessive wandering particles of graphite that is NORMAL in wear from the clutch packs inside the tranny. You are MORE brilliant for asking a proper question like this and doing preventative maintenance. Don't necessarily trust quicky lubes or even many trans shops for this service. Many times, their equipment is contaminated with many types of different fluids. Same thing goes for Firestone and other auto chain car maintenance centers. GM delaers shold offer you a WARRANTY for this service, so you have something to back any troubles on. REMEBER that your trans holds many quarts of olde and useless fluid inside the valve body and the torque convverter. A simple drain and fill does NOTHING more than thin things down. This is why many trans servicings FAIL!!!. ALL transmissions require the proper flushing and filling of fluid every 100,000 miles or so. It is a WIVES tail that changing the fluid will "stir up trouble" and cause trans failure. Most failures occur from improper fluids, and improper cleaning of the valve body during servicing, or shops that do NOT know what they are doing, or even sabotage the trans. GOOD LUCK!! ALL fluids lose their properties over time, even brake fluid and steering fluid. With GM cars, the COOLANT is a BIGGER problem!

Normally it should be a kind of bright red. So if dark then change it and the transmission filter. Have the filter opened (in front of you) and look for flakes. If there are only a few then good but if there is a lot of flakes then that indicates the clutches are losing material and may be part of the problem with the transmission. Sometimes just changing the fluid will make a nice improvement.

the 2007 grand prix normally doesn't have a transmission dipstick it is sealed for life and the fill plug and level plug are underneath and can only be checked by a GM dealer or specialist , if it was manufactured in 2006 check the plastic plug on top of the dipstick is red or orange , if the fluid doesn't smell at all it isn't transmission fluid

Changing the fluid can't make it any worse. If it fails, it was already on it's way out. Typically "funny" shifting from an auto trans isn't due to the condition of the fluid, no matter how bad, because by the time the fluid can no longer do it's job, the transmission has already had irreparable damage done to it, requiring a rebuild.

Draining the fluid, changing the clear out and including sparkling fluid is a huge thought. it does not be a good thought to easily "flush" the transmission. this might contain forcing the previous fluid and debris out employing pressurized fluid. this might probable be undesirable yet changing the fluid could be a good thought. even once you drain and top off there'll nevertheless be a good quantity of the previous nasty fluid interior the torque converter that isn't come out so it relatively is fairly useful to do yet another drain and fill after employing the automobile for a jointly as when you alter it the 1st time...if it relatively is going to circulate.

If the transmission oil is very dirty you need a transmission service, if there are pieces of metal fragments in the oi,l the transmission may need replacement, you may be able to buy an exchange transmission cheaper than buying one brand new, just see how the transmission service goes first, then may your judgement, lots of luck. John

I recommend getting your vehicle into your local General Motors dealership that services Pontiac vehicles. They will be able to provide you with the information that you are needing and a price on the work that needs to be done.

Michelle, GM Customer Service

no flush or you could wind up buying another transmission ! what it needs is the pan dropped and change the fluid and filter ! the fluid has been in there too long and starting to get dirty ! but don,t flush it !