I have a 98 Trans Am, its 5.7 liter automatic. The problem I am having is weird noise when idle. Idle low (500 rpm, it suppose to be around 1000), loss of power, and when at full stop it hesitate when running again. I started having this problem about a week ago, but the low Idle; since I bought the car (about a year ago). At first the idle wasn't that bad it would shake a little (low compression maybe, because my car would sound quite at a stop light). It only did that in drive, it would not have this problem in reverse nor neutral. Also when I start the car it turns on weird (it idle high for a bout 30 second (1400 rpm), then they go super low (500) and back to around 900 rpm, also happen when I shift into drive or reverse. I wanted to fix the problem before it gets worse. First I removed the throttle body and there was a lot of carbons build up. Cleaned but nothing, problem remained. Second I changed the idle air control valve, new MAF sensor, and speed sensor, but nothing. Third I gave it a tune-up, changed the oil, sparkplugs (iridium), and wires. When in the process of doing this, I notice oil in the spark plug chamber (a lot). I think that is why I am getting the low Idle. I know that it could be one of 2 things, the piston rings could be bad or the valve path is leaking oil because of bad seals.(How can I tell?). A month later I stated hearing this noise (bang, bang, like if something is hitting); this only happen in drive, but now even when in park. I just don't know what to do. I don't want to take it to a mechanic because where I live(Laredo) no one knows what to do and I also get the run around(like it the fuel filter, I sure, I put a new one a week after I bought it) any help on this matter, would be great. Oh and it now making a clicking noise, I think it's from a valve. My car is just messed up! Help!
Mods-EGR removed, block off plate. (Is the computer supposed to be programmed for this?
New headers and y-pipe- SLP
New exhaust muffler - Flowmasters
MAF - modification
Oil changed - put thicker oil because mechanic told me it would help (it didn't) - 160,000miles, 5w30 to 10w30.
New spark plugs - Delco iridium and MSD wires,
New oil filter - K&N
New air filter - K&N
New thermostat - 160 degree
New Speed Sensor
I put some additive in the gas- NOS, etc
Oh and a throttle body bypass (for coolant)
And also fixed the secondary air system, the smog pump was broken(don't know why, I don't thing I need it)
I havent had time to check what you asked me but will get to it this week. Thanks
Monday, March 31st, 2008 AT 2:09 PM