98 Grand Am GT, engine shudders while idle, sputters off the line

[jinexile]

I'm getting ready to purchase a new car, my first actually since this was a hand me down from the parents. So I really just need a cheap fix to make sure it lasts a few more months.

It's a 98 Grand Am GT 3.1L Fuel injected V6, auto trans

Lately it's been sputtering when I give it gas on a green light. Intermittently while I'm stopped the engine will shudder as if it's about to stall it idles at around 600-800rpm. There is also a drop in acceleration while driving, there used to be noticeable torque when passing people on the highway but now it's pretty gutless.

I'll admit I didn't treat this car very well, other than regular lube jobs and balancing/alignment on the tires, I haven't done much preventative maintenance on it, so I can imagine it could be a number of different things and I wonder if anyone out there round up the usual suspects?

Thanks

[jinexile]

Ok either my car is messing with me or I just didn't wait long enough for the fuel injector cleaners to run their course but my drive home was like my car was five years younger.

I still got a CEL and I'll need to check that out but it's it magnitudes better.

[jinexile]

Looks like I spoke too soon, gave my buddy a ride a few hows later and problems were back. I just don't get it, if I were a guessing man I would say electrical but I'm a noob.

[barmanjay]

#1

your CEL comes on,.. go to Autovalue and ask them to check what your code is

then we can go from there.

chances are it's gonna be a few things.

coilpack/module
plugged cat
bad o2
plugs'n'wires



hey,.. did you check your oil?

coolant? are you running hot?

[jinexile]

Oil levels are fine and color is good

Coolant levels should be good as well, but I noticed it did start getting hot when it's having problems. I figured that was due to the A/C being on and the engine having to work harder due to misfires.

I'll stop by the autovalue after work today and get the codes for the CEL.

[TurboZombie]

Could also be a plugged fuel filter.

[jinexile]

Ok hit up Autovaule, The NW location moved outta ranchlands btw it's in Crowfoot now near the BPs right by the liquor store.

Cylinder 4 misfiring. I tried changing my all my spark plugs and cables, they were pretty ratty so they needed changing but that's not the problem. It's still running rough.

I noticed that there is a slight smell of gasoline when the engine is running and I'm under the hood, I don't know if that's normal but I'm guessing not.

[TomcoPDR]

Try a new injector in cylinder #4, they're not cheap for OEM though.

[barmanjay]

10-1 it's not the injector

it's the coil pack/module causing the misfire

I'd go to PNP and get one off of any 2.8/3.1 cavalier/beretta or 3.1/3100 grand am/malibu,.. or even a 3400 grand am/alero/impala

They are all the same

if you are smelling gas,.. could be an upper intake gasket

Do you have a leak in your exhaust?

if you do and it's near the engine bay,.. a misfire will send gas into the exhaust and you will smell it.

[jinexile]

Thanks guys, I think I'll try the coils first since their a little cheaper and easier to get at.

I've been reading a bit and I've seen that these Grand Ams have a problem with the intake gasket after 80,000 miles (~130k km) my car is now at 144k km so this seems like a likely candidate as well.

(BTW, g'damn were the back three spark plugs a pain the arse on this engine, took me 10 minutes to replace the front ones and an hour to change the back.)

[barmanjay]

Good luck with that,.. yeah the back three are a PITA