I would really appreciate if someone can shed some light on the problem.
Car: 2002 Toyota Camry - 4 Cylinder
Odometer: 165000 miles
- Couple of days back, when I started the car it had a rough start(rough idle).
- Once on the move I did not feel any issue in driving.
- On the way I stopped at the store and when I started the car again “Check engine light came on”.
Auto center OBD-II diagnosis came up as P0303-Cylinder 3 misfire detected.
Technician found burned cylinder 3 spark plug. Hence technician replaced all 4 plugs to iridium spark plugs and did 3-step fuel cleaning (1.Oil System 2. Fuel System Cleaner 3. Intake Cleaning).
Check engine light went away, drove 15-20 miles and next day when I started the car light came back on!
Filled up Supreme grade gas, to see if it helps
Again took it back to the garage, OBD-II Code: P0303-Cylinder 3 misfire detected. And they replaced #3 coil.
Once again code went away. Drove couple of miles and once again when I shut off car and restarted, check engine light showed up again (OBD-II Code: P0303-Cylinder 3 misfire detected).
Also, technician mentioned that when check engine light was on, OBD-II tool identified cylinder 3 misfire happens only at the start, especially when engine is cold. When car is on the road, it does not register any misfire even when engine light is on!
I have noticed that since the problem started with rough starting idle, every time “Check engine light” came on when I started the car and drove around 100 ft.
There is no egg-smelling odor (to eliminate catalytic converter failure)
Couple of other things…
- Since last summer while changing air filter, Vacuum filter valve’s (Toyota part: 90910-12199 [084600-5480 12V] 548 Denso-Japan) outlet tube broke from one of the vacuum tube. Which I tied back with wire. Don’t know whether this could cause any issue of P0303 after several months!
- But since last month or so, when car is stopped and move by pressing gas pedal, I hear flow of coolant noise (behind the dash board-into heat chamber). Somewhere I read that due to vacuum leak or lack of coolant in radiator could cause these symptoms. The coolant reservoir and radiator is full. Temperature gauge is half way when car is running, there does not seem to have excess heat. Also, RPM gauge does not fluctuate at all.
- Engine valve cover gasket was replaced last spring
- Last spring I got the coolant flush service done
What should I be looking next?
- Vacuum filter valve?
- EGR valve?
- PCV system?
- Fuel injector?
- Gas filter?
- Blown head gasket?
- Intake manifold?
UPDATE: Technician rechecked #3 spark plug and coil and light went away for at least 2 days and came back on. Also, noticed some oil leak and heat gauge at little over half mark when running.
Thank you so much for your response.