1

I have Toyota corolla 2000, which is difficult to start at times and it starts normal at times.... But these days I experience pop sound when starting the engine form the exhaust.. Engine of apromx. 200k miles

  • Typically that represents a timing issue (either cam or spark). How many miles on the engine? – zipzit Apr 25 '18 at 6:02
  • 200k. Miles on the engine – Gabriel Apr 25 '18 at 6:46
  • Do you have an OBD scanner? If you haven't, i recommend you get one, do an OBD scan and post any PTC codes here, provided the MIL light is on. – Al_ Apr 25 '18 at 11:01
  • One thing I’d like you to try. When you go to start the car, turn the key to on. Listen for the sound of the fuel pump in the fuel tank. Let the pump run for two or three seconds. Then turn the key to the start position . Does this make a difference in start up? – zipzit Apr 25 '18 at 14:37
1

In my experience, a pop at start indicates excess fuel/air in the cylinder at the wrong time in the four cycle combustion process. This could be a problem in:

  • valve timing (worn chain?)
  • valve sealing (burnt valve?)
  • or perhaps leaky fuel injectors.

Oh, and my request for a pre-start fuel pump run is to test for leaky fuel injectors.. I'd suspect you get more "pop" at startup in that circumstance...

200,000 miles on the engine is a whole lot. Frankly for that car, I'd suspect that is end of the engine's life expectancy. How long were you expecting this engine to last? How noisy is it? Any oil leaks on the ground? (both of those indicate lots of normal use engine wear...)

  • How noisy is it? No noise, no oil leaks – Gabriel Jul 1 '18 at 19:43
  • @Gabriel One thing I’d like you to try. When you go to start the car, turn the key to on. Listen for the sound of the fuel pump in the fuel tank. Let the pump run for two or three seconds. Then turn the key to the start position . Does this make a difference in start up? – zipzit Apr 25 at 14:37 – zipzit Jul 1 '18 at 21:16
0

Backfire is caused by the exhaust system containing gasoline vapor and air from cylinders that did not fire. When a cylinder fires, flame in the exhaust ignites the vapor . If severe , it can blow open a muffler/resonator. The cat converter does not have any affect when it is cold.

  • So, what is the The solution? – Gabriel Jul 1 '18 at 19:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.