Bought my first GP need some help!

[CyxRyan]

Hello everyone, My name is Ryan and I just joined because I bought my first 2005 Grand Prix GT 3.8, 110k Miles and need help.

Fresh Oil Change, Oil Filter, Air Filter.

Car History: A young lady owned the car previously and owned the car since 2007. She recently moved out of state and left her car at her parents house. She was planning on coming up to get the car but then decided to just buy a car near her. The car sat the whole winter which I believe it was not started at all which brings me to my first question. The battery was just replace because the other one was dead. The father bought it from "Discount Battery" and im not sure what brand it is but im sure its some cheapo battery because its small and CA is 440 and CCA is 550. When I was checking out the battery I noticed I had at least "1 in" on both sides and "1 in" in the back.

I want to know if this battery is to small for my car because I noticed sometimes when I go to start my car that it will start run for a second then die. When it does that I will start it again and tap on the gas then it will run fine. When I turn the steering wheel or put my foot on the brake and shift through "Park, Reveres, Neutral, and Drive that I noticed sometimes my head lights will dim and radio. I'm not sure if its the battery or if its just because it sat for awhile and is acting up. I do not have any codes or engine light on.

When we test drove the car my dad shifted through each gear and it was super smooth, no jerking or anything. Last night when i got home from a friends house and when I noticed the lights going dim from shifting, I also noticed when I shifted from Neutral to Reveres it would jerk a bit and my feet could feel it. I read it could be a bad mount but it only did this last night. The car drives and shifts smooth so I don't think my transmission is bad. I also check the transmission fluid and it was still good and at the right level.


Any helpful advise would be much appreciated!

[importisland13]

welcome to the forums

[Timing]

Welcome and yes you should have a 750+ cca 34 series is the correct size i believe

[Jevik]

The bettery is pretty much used to just start the car. The car should run fine without a battery altogether. It sounds to me like a connection somewhere. Check your grounds and have the alternator tested. Make sure all the power wires are clean and tight.

[Jevik]

I run a smaller battery on my accord. Doesn't affect much, just takes an extra crank to start. And yes. Welcome to the forums.

[dsmuts]

Clean your tb and it won't die after starting anymore

[addzradd]

You most likely have a 75 series battery installed in the car, which came stock in Grand Ams and other N-bodies. Our come with a 78 series, both should work just fine to crank over our engines.

Most batteries are made by the same company, Johnson Controls so branding isn't that important it is just a sticker on the side.

I would start by checking how many Volts your Alternator is outputing, and checking all of your connections it may just be a bad ground, which can get corroded quickly if someone leave a car parked all winter, outside on a surface that is not concrete.

Beyond that I might check out your spark plugs and other tune-upables just as a precaution to having a new car.

[02NavyBlue]

Welcome.
The recommended battery CCA rating for my 02 grand prix is 690, I would always keep it around there or higher. Below will start your car since the starter only requires about 150 amps, but it will not last as long as a battery more suitable. By 1 inch I assume you have space in the battery box, that is normal even for a 700 CCA rated battery which is what I'm using and have the same amount of space.

It's common for the 3.8 to have the problem where you may have to give it a little gas to get them started, I test drove 4 GP's before buying mine, and the first 3 did the same thing. The problem is likely a dirty throttle body, or a MAF sensor that needs cleaning.

It is normal for the lights to dim a bit when shifting from park to drive or reverse when at idle, the RPM's lower when doing so, and naturally your alternator will not output as many volts for that short time. When going from 1st to 4th, it shouldn't happen though.

When shifting from park to reverse it may jerk a little bit. Next time you try it, look at your RPM's just before shifting. I notice that mine does it a lot more if it's on a high idle than when it's at 850 RPM's, which is normal.

[CyxRyan]

After work I got into my car and started it and the RPMs were about about 1000-1200 then slowly went down. When i got home and I put it in neutral my RPMs were about 700-800 RPMs and when i put it in reveres my RPMs drop down to about 500-600 RPMs. It does make a funny noise when I put it into reveres so I might have a bad trans mount?


Thank you all for the welcomes and helpful advise! =D

[02NavyBlue]

When you started it and it stayed around 1000 - 1200 RPM's, that's a normal high idle for cooler weather. Mine goes to 1,500 rpm when cold, and around 800 normally.
Depending on the noise, it's probably normal. Mine makes a noise when putting it into reverse only, it doesn't do it in drive. It's just a click, like something engaging.

[CyxRyan]

So my idle seems fine then! I went from a 97 Ford Ranger to a 05 GP so its different by a long run!. The Neutral to Reverse concerns me cause I guess you can say it clicks but I can feel it with my feet. So I was wondering could a trans mount be bad?


Cool your from Michigan too! ^_^

[02NavyBlue]

Yeah it was my first experience with that high of a normal idle too. I could maybe record the noise mine makes but it' not real loud, not sure if the camera would pick it up well, I'll see. I do feel it as well, all sounds normal to me.

And yes I'm north of Detroit, where we're finally getting some warmer weather (55-60°F) but it's pretty windy. It was already 80°F before today last year.