I have a 2003 Toyota Corolla 180,000 miles with a rough idol. Especially when the a/c is on. No check engine light or codes. I have thrown the parts cannon at it. Please help 🙏.Â
Four new engine mounts
Four new cool packs
New spark plugs
New idle air control valve
New intake manifold gasket.
New mass air flow sensor
New PCV valve
New PCV hose
New fuel filter.
Clean the fuel injectors
Cleaned the throttle body
New air filter
New VVT actuatorÂ
Smoke tested for intake leak. no leaks found.
Now that the parts cannon approach has, as usual, failed it's time for some diagnosis. A good start would be a compression and/or leakdown test to verify internal condition of the engine. Another would be to go beyond codes, which are only a starting point, and look at live data for suspicious items.
