Thread: Grand prix issue w/gear i think

Ok im not sure if its the gear or not but my bro's 07 Grand prix Base has been lately having this jolt from the car a few time when he accelerates from a stop. when we stop at a red light then start going the car move forward a little and we can hear the engine getting louder and then the car like gives a great big jolt and then starts going. I don't know how else to describe it and we don't know what's wrong with it. the car hit 100k mile just 2 days ago and the big jolt that happens has been going on for a while now but we did not get the car a big exception yet but we will need to, you guys know what's wrong with it?

1. Change the fluid and filter. Use Dex VI. I wouldn't recommend flushing it at this point since the lack of maint. may pose issues but others may say different. Your call. When the car starts to move forward and then you feel the jolt, does the tach kind of spike a bit right before the jolt? Trans could be slipping.

2. Bulb burned out for the gear indicator. Replace it.

3. Check the condition of the engine and tranny mounts. They may be bad since he races light to light all the time.

4. Have you ever changed the fuel filter?? If not, then I'd start there. And also clean the MAF using actual MAF cleaner, not carb or brake cleaner as you will destroy the MAF. That may solve your hard start issue.

Well he does not race every sec just once in a while but other problems have happen such as there was a leak in the coolant where this plate in the engine was burned out, when they fixed it and put a new performance plate on it and put a new coolant tank and its been good since. that happen like a few months ago. we will have to change out the fluid then and as for the fuel filter we had changed that like long time ago too. we will check ALL issues in the car and basically give like a whole operation on the car so that everything is fixed and also im not sure about the filter. we have a K&N air filter but for the fuel filter i dont think we have a K&N one but we will have to see later when we get more $$$. but either way i just wanted some ideas of what can be wrong with it so we can check it later and let the mechanic know too. thnx for your guys help and any more info would be great.

Originally Posted by FordMan77

1. Change the fluid and filter. Use Dex VI. I wouldn't recommend flushing it at this point since the lack of maint. may pose issues but others may say different. Your call. When the car starts to move forward and then you feel the jolt, does the tach kind of spike a bit right before the jolt? Trans could be slipping.

2. Bulb burned out for the gear indicator. Replace it.

3. Check the condition of the engine and tranny mounts. They may be bad since he races light to light all the time.

4. Have you ever changed the fuel filter?? If not, then I'd start there. And also clean the MAF using actual MAF cleaner, not carb or brake cleaner as you will destroy the MAF. That may solve your hard start issue.

I'm guessing that the problems only exists on a cold start and goes away when its warm. As stated, your best option now is to change the tranny filter and fluid. I as well strongly encourage you NOT to do a tranny flush. As a flush can dislodge or move any shavings or contaminates and would be harmful to the tranny. After getting your tranny serviced, if the problem still exists, your probably looking at a rebuild. Check out this link, No Forward Cold , its common issues that our fellow friends over at TEP has posted and explanations.

Also, as for the cold start, get some MAF safe cleaner and clean your MAF sensor. Since you said your brother uses a K&N CAI, K&N are oiled and the oil collects to the sensor causing faulty readings. It is highly suggested to clean your MAF with an oiled air filter at least every 6 months or 5k miles. Every 3 to 4 for for dusty climates or if you notice issues. As for the fuel filter, the fuel filter is part of the fuel pump and should be good the life of the fuel pump.

Originally Posted by cerick08GP

Yup, I figured. Sounds like code for NEVER.

I have a little philosophy when it comes to transmissions. You can do a lifetime worth of fluid changes for the price of one replacement transmission.

This is a great philosophy and should take advice from it. As long as your always check your fluids and properly maintain them, these cars will last forever. Always check your engine oil, tranny fluid, and coolant, and always address their needs.

Thats for the post ill take your guys advice and its great that its on this forum for me to look back at, thanks a whole lot this can really help keep are car strong and alive
Btw i said my bro has a K&N Air Filter not a CAI.

Originally Posted by Vette Zr1

Thats for the post ill take your guys advice and its great that its on this forum for me to look back at, thanks a whole lot this can really help keep are car strong and alive
Btw i said my bro has a K&N Air Filter not a CAI.

Regardless cone or drop-in, K&Ns are oiled filters and need proper maintenance.