I have a question... I have a 1999 Pontiac Firebird. In the morning the car was driving fine as usual...but in the evening time when I got in and started it up to go down the rode, about 2 minutes after driving its started shaking pretty heavily. It also sounds alot louder when driving and while in park, and while your foot is on the brake. When the car is in reverse it shakes harder, and when you slow down towards a red light and take your foot off the brake it shakes the hardest.... It's seems as though it has also lost power, when started to go from a stop...
Any clue as to what this could be?? No smells or fumes are coming from the car..just the sound and the erratic shaking...
Any help would be appriciated... Also SES is on...when it first started yesterday it was solid..now it is flashing...
Thanks guys...

 

i had a fiero with a similar problem although i dont know if applies to you, but check to see if your TCC solenoid is bad.

 

I'm sorry..but what is that? Whats it do??
I'm sorry...obviously I'm female... not TOO car inclined...but I really am trying...
Thanks for the response...!

 

if i remember correctly, it is the solenoid that i believe that it actually locks up the torque converter and if its starts to go bad, it produces some of the symptoms that your describing.

 

Yup...not familiar with that part....is it quite costly to fix..if you know..I'd appriciate it? Also, anything I can have checked to verify that is it before I take it to a mechanic that may try to rip me off???
Also, someone else told me it could be spark plugs need to be changed..is that also possible??
Thanks again...

 

On the right side of your transmission, just above and behind the shift linkage, there is a four pin square connector, with a few wires. Disconnect it and drive. See if your problem is fixed and let us know.

 

The spark plug possibility would be the easiest thing to check..just pull one or two out and check em out....if they are fouled or just really dirty...they may lead to a problem similiar to yours....

I'd say check that out first....

do you knwo how old the plugs are in your car?

 

so got the codes.. it says DTS (codes)

p0306
cylinder 6
Misfire detected

was told could be spark plug, wire, or ignition coil..?
could it be anything else??
Bought all those parts anyway to have all three replaced..but could it be anything else?

Thanks again guys...

 

usually it the wire or the plug itself....

 

this happened to me while i hit the brakes, the whole car would shake so bad i felt something was gonna brake.

i had to actually replace the rotors

 

no, this isn't happening when I brake...it's right before I brake, or let off the brake., or drive., reverse., idle. It is always shaking..it doesn't have anything to do w/ the brakes.. I just put brake pads on it last week anyway...and the ses light is on...thanks anyway though....

 

It's hard to diagnose a car that hasnt been tuned up recently. After that's accomplished you can see where you're at.

 

sellmans got a point..i know your trying to get to the bottom of this particular problem but after this is solved go ahead and do all the basic mainteneance stuff ...if your not sure what needs to get done or havent had the car too long just do a search for on it..vader did a good write up a long time ago on what to do to a new car...well new to you car...

 

These late model cars are very hi-tech and hard to diagnose without the right test equipment. You could spend a whole bunch of money and not get it right. With this engine it is very common to have a coolant leak into an end cylinder through the intake, new ignition parts won't fix it but an $800 intake R&R is required. Hopefully this is not your problem but I'd sure suggest taking it to an expert and not throw a bunch of money at it without knowing what's wrong. I'm a pretty good hammer mechanic but I wouldn't hesitate to take mine to someone up to date on it.

 

PO306 is a misfire on #6 cylinder.
If I'm not mistaken, that car has individual coil pasck for each cylinder. I could be wrong, it's been awhile since I popped the hood on of of those cars.

Here's what I would do.

Take the coil pack off of the #6 cylinder, and swap it with the #4 coil pack, if you get a code that's PO304 misfire #4 cylinder. Then you know your problem is a coil pack. I think those are about 55-60 bucks.

While you're at it you might as well change all your spark plugs as well.

Hope this helps

Chris

 

cool thanks guys...got the coil pack for $20 at advanced auto..and I'm having all spark plugs changed...
appriciate all the help boys....

 

I am an idiot!!!!! I just now realized this isn't a third gen. I was giving info for an 700r4 not a 4L60

 

4L60-E... The poster might have more luck on a forum that deals with 4th gen cars, seeing as how no thirdgen came with OBD-II, much less a DIS 3.8L V6...

 

Or a forum where people give out systematic diagnostic advise rather than a bunch of "shoot from the hip", WAG's. What a terrible thread this has been.

 

Turned out to just be the the wire...got it fixed car is running great...thanks guys!