trey1010

iTrader: (3)

I just purchased a 1999 Pontiac Trans Am WS6 6 speed!! And my lord is it fast... I will get some pics up 2morrow.. One question, when the car is going and is at very low rpms, say under 1500 there is some pinging, But when it is pinging it as the point were i should downshift.. It stops pinging when you pick up speed in that gear...???

Fibbado

iTrader: (8)

Congratulations on your purchase, laying down black stripes already, eh?

First of all what is your level of experience with cars?.. I only ask because before anyone responds it's best to know wether or not you are in fact talking about pinging from the engine or some other "noise" that some people might describe as pinging.

trey1010

iTrader: (3)

I dont have to much experience, So what all should i check? and if it is in fact pinging should i be xtremely worried?? and thank you!! no black stripes yet....

sectari

iTrader: (2)

"pinging" is premature detonation of the gas and air in the cylinder. Yes, it's not good, but the car has sensors and automatically adjusts for it. Remember that our cars need 91 octane (or 92 if you can get it)- the low-octane stuff will cause pinging. And it tends to happen at higher RPM/loads. The brand of gas you use _may_ impact this in some folks' opinion.
Now, "lugging," on the other hand, is when you're trying to run in a gear that's higher than you should, RPMs are very low, and the engine doesn't like that and doesn't run smoothly. Do you think that's what you might have?

Congratulations on the purchase, and welcome.

-sectari

trey1010

iTrader: (3)

Well, i def had in say 4th when i should of had it in 3rd... It may have been "lugging" but there was a slight rattle sound.. hopefully that is the only problem..?? and thank you!!

Fibbado

iTrader: (8)

I was just suggesting that since you don't know that much you might be hearing clutch chatter, RPM vibration/resonance, etc.

Yeah pinging is not a good thing, your motor will go into "limp" mode, basically it will pull timing to prevent the pinging so you probably wouldn't hear that without your SES light being on.

Give us an example of your symptom, like you are hearing this in what gear, then you downshift and it goes away as you speed up. That sounds like chugging as Sectari pointed out, but that is more of a resonance.

Remember these T56 trans's are geared for very high speeds and have very long gearing. Which is why 4.10 gears are an awesome swap. Dropping the car into 6th is not always the best way to save gas or cruise.

trey1010

iTrader: (3)

Yeah thanks for the quick replys... Yes there is no ses light on... and i will try to explain.. Say i am in 3 and the rpms are just about right and then i shift into 4th and the rpms are down below 1500 and i have the pedal to the floor i can hear it till about 2000 rpms... does that help?

sectari

iTrader: (2)

I think you're probably alright. sounds like lugging/chugging to me. You're not going to get good acceleration out of the LS1 engine at low RPM- and if you try it won't like it a whole lot.
edit: -presuming you're hearing what I think you're hearing, because my car doesn't like that either and sounds kind of like an irritable mechanical dinosaur being roused from sleep. Probably not a terribly useful description. There is a bit of a higher-pitched clacking sound that goes with it, if I remember correctly (I try not to do that often!).

-sectari

question

iTrader: (2)

Wait, you are in 3rd, shift to 4th, RPM's drop to 1500, which should be a good cruising speed for the engine to be at. You floor it, and the motor still bogs when you accelerate?

JD_AMG

1500RPMs is perfectly fine for cruising, hell I cruise at 1000RPMs all the time. Could this noise be described as a metallic rattle? Check for exhaust rattles, the 02 sensors can come loose pretty easy, my passenger side one did and it rattles a lot.

trey1010

iTrader: (3)

ooo no sorry, it isnt bogging... you just hear a rattle.. and yes it does kinda sound like a metallic bouncing around... i was kinda thinking it was something loose because it does it at low rpms when theres more vibration...

sectari

iTrader: (2)

okay, memory did not serve me right- tested this on the way to work-
I don't get anything "rattle-like" unless I'm way down in RPM's- like 600.
like jd_amg says, check those o2 sensors- they are known to do that.
When I got my TA, the whole exhaust system (from the cats back) needed tightening.
good luck.

-sectari

sobaka79

iTrader: (1)

hehe,
he means two black rubber strips left on the asphault, not pinstrips....

trey1010

iTrader: (3)

yeah lol i knew what he meant... lol

30thanniv

iTrader: (2)

Could it be the infamous ls1 tick?

NDFORSPD

I would put my money on a loose heat shield or something like that, especially if its only doing it at sepcific revs....ie 1300-1600 or something like that. best bet is to get under it and make sure nothing feels loose

trey1010

iTrader: (3)

ok i will do that this weekend! thank you everyone for the help.. And if i must say these cars are scary fast! I dont know how i would ever race it without it going sideways into second!

trey1010

iTrader: (3)

Here are some exterior pics!

autotrix

iTrader: (5)

How's that passenger window work???

trey1010

iTrader: (3)

lol well it works fine at this point.. lol if it stops i know who to go to! lol