Hello
I been working on my 1997 Grand Prix gt for over a year and it just wont finish to get it fixed... the major problem is, that my car looses power after running it for a little while, especially driven on city. when I start the car on the mornings, it will run great with full power, but after a little while of heat on running engine , feels pretty heavy and burns fuel faster. This happened after I overheated my car one day maybe a year ago, and blew of a head. I replaced a head with a rebuilt one and set the new gasket kits for top engine. And also replaced water pump, spark plugs and wire set. After every thing was done and back to place, the car had a weird knocking sound on the engine, the mechanic said, that it was only a lifter, and that it could be fixed with an additive (Lucas)... It never did. After that day I took it for a test drive, and my car was running very slow and smelled really bad like gas. I took it back to the mechanic and have him replaced the fuel injectors...The car was running better after that, but i notice that every time the car ran for a little while randomly looses power, so I did a good tune up replaced a bunch of sensors like the map sensor, maf sensor, idle sensor, purge valve sensor solenoid, canister vapor tank, transmission fluid and filter, cleaned the throttle body, I even put high performance cables and a intake kit. I even replace the fuel filter and checked the fuel pump. two days ago I replaced my whole lifter valve kit and that knocking sound still there, the mechanic said it could be the camshaft. the car its been running better, but still not like it use to. some one told me that it could be the o2 sensors, but my check engine light isn't on, and I was thinking it could still be that, because when the overheat problem happened a lot of water came out of the pipes. please some one help me, I pretty much tried every thing so far, and I really like my car I would hate to get rid of it.
Thanks!
