09-14-07, 10:55 AM
I timeserted by 96 STS with 110k miles. I had been using coolant for several years and last spring it got bad. I did see some buildup on the piston tops and started getting a P0300 code. I have only driven it 100 miles or so this week and it does not start smoothly. kinda rough and an occasional stumble at idle. seems to accelerate smooth though. runs ok on the highway. I was expecting it to run perfect. put a few more miles on and see what happens.
09-19-07, 01:29 PM
hi just want to know did you get the p0300 code before headgasket job are after job? I have the same code and car idles rough all the time it hesatates or misfiring the car by the way is 98sls in triffic temp gauge moves a little pass center fan comes on and gauge back to middle scared of headgasget problem.
09-19-07, 02:28 PM
I got the code before the job. it looks like both gaskets had some blowby though the odd side looked worse. on both gaskets, it looked like it was between 1-3 and 2-4. my car never ran hot, it just went from using a quart per month to about 1 gallon per week. than the code and miss starting showing up. i have only driven it for a week now and it seems ok but not perfect.
Have you changed plugs & wires? Have you cleaned the EGR valve?