GSTjordan831
Probationary Member
- 12
- 0
- Aug 26, 2020
-
Salinas,
California
Hi guys I've got a few problems I've been trying to diagnose for months now I've read countless threads chased many leads but haven't found a definitive resolution to any of my problems. I have a 98 gst a/t, I've had a
#1 misfire problem for a while now, when I bought the car it ran amazing and one day on the freeway I'll admit it was really stupid of me but at the time I didn't know what the overdrive button did. So when i was on the freeway i let off of the gas and i pressed it and didn't notice a difference so i pressed it a few more times in a row and than (I wanna say, i might be wrong due to this happening a while ago but I'm pretty sure there was a clunk) the engine made a small clunk and the check engine light turned on. So immediately upon getting into town I did a obd2 diagnostic check and the code P0300=random misfire came up so I've changed the spark plugs and wires I checked the voltage on the coils I did the lazy test of unplugging the injectors to see of anything changed and everything seemed to be fine, but everytime I hit 70mph it starts misfiring until I come to a stop and when I continue from the stop it drives normal until I hit 70 again and when I drive a few days with out ever hitting 70 or full throttling it the check engine light clears itself and only comes back on when I go full throttle or hit 70mph. Upon changing to new spark plugs it ran like no problem ever occurred and I was able to go 125mph with out any issue and slowly it's back to whenever I hit 70mph or full throttle it. Also everytime upon initial startup a
#2 puff of white smoke comes out and smells kinda like burning plastic but it only happens once a day even of I let the motor completely cool down or doesn't happen again until the next day even if its morning or night or in the middle of the day on a hot summer day it does the white smoke always on the first start up of every day. And every time I start it up my
#3 turbo starts dry even if I turn off the car and immediately turn it back on again if I go to hit boost it sounds like the turbine or bearing scraping like it has no oil but after a few times of hitting boost to basically "prime or pump it" it doesn't make that sound again until I turn it off and back on and the
#4 blow off has slowly gotten almost completely quiet when I first got it and I hit boost and let off the bov was really noticeable it wasn't LOUD but u can definitely hear it and I loved it but over time it's almost silent now i can hardly hear it, it sounds the loudest when I drive it for the first time for the day but once i turn it off and back on and I hit boost and let off its actually completely silent and u can not hear it blow off.
I just don't know what to do about these problems
I know its an incredibly long post but PLEASE HELP ME
#1 misfire problem for a while now, when I bought the car it ran amazing and one day on the freeway I'll admit it was really stupid of me but at the time I didn't know what the overdrive button did. So when i was on the freeway i let off of the gas and i pressed it and didn't notice a difference so i pressed it a few more times in a row and than (I wanna say, i might be wrong due to this happening a while ago but I'm pretty sure there was a clunk) the engine made a small clunk and the check engine light turned on. So immediately upon getting into town I did a obd2 diagnostic check and the code P0300=random misfire came up so I've changed the spark plugs and wires I checked the voltage on the coils I did the lazy test of unplugging the injectors to see of anything changed and everything seemed to be fine, but everytime I hit 70mph it starts misfiring until I come to a stop and when I continue from the stop it drives normal until I hit 70 again and when I drive a few days with out ever hitting 70 or full throttling it the check engine light clears itself and only comes back on when I go full throttle or hit 70mph. Upon changing to new spark plugs it ran like no problem ever occurred and I was able to go 125mph with out any issue and slowly it's back to whenever I hit 70mph or full throttle it. Also everytime upon initial startup a
#2 puff of white smoke comes out and smells kinda like burning plastic but it only happens once a day even of I let the motor completely cool down or doesn't happen again until the next day even if its morning or night or in the middle of the day on a hot summer day it does the white smoke always on the first start up of every day. And every time I start it up my
#3 turbo starts dry even if I turn off the car and immediately turn it back on again if I go to hit boost it sounds like the turbine or bearing scraping like it has no oil but after a few times of hitting boost to basically "prime or pump it" it doesn't make that sound again until I turn it off and back on and the
#4 blow off has slowly gotten almost completely quiet when I first got it and I hit boost and let off the bov was really noticeable it wasn't LOUD but u can definitely hear it and I loved it but over time it's almost silent now i can hardly hear it, it sounds the loudest when I drive it for the first time for the day but once i turn it off and back on and I hit boost and let off its actually completely silent and u can not hear it blow off.
I just don't know what to do about these problems
I know its an incredibly long post but PLEASE HELP ME