popcorn

[2007yaris]

Today I have changed my oil in my 2007 yaris twice. After the change I noticed a "popcorn" sound from the engine taking off from a dead stop - it stops making the noise when the engine is revved. I thought it might be an inferior oil filter which is why I changed it twice and still the sound persists. please help - thanks

[bankrobber]

That sounds like a problem. Check the serpentine belt

[2007yaris]

I checked the belt - seems ok and tension is good - am I missing something?

[DARK AGE 53]

Pre-ignition?

[2007yaris]

It's really weird - happens when slowing down - sometimes at idle - upon accelerating about 15-20 mph it seems to be gone - almost like a grinding sound as well - I can't figure it out -

[2007yaris]

I put my hand on the bottom of the filter when it was running - felt some really hard palpitations - i don't know if that is normal -

[DARK AGE 53]

Do you feel comfortable removing the serpentine belt, that might help isolate the problem.....you wouldn't want to run it very far though.

[Kaotic Lazagna]

Either take it to a mechanic to have it checked out or take a good quality video for us to see/hear what sounds you are referring to.

[2007yaris]

I do live in the mountains - my wife told me recently that the windshield washer fluid was empty, even thought I just filled it - when I opened up the hood the top of the washer fluid was off - I'm sure the fluid went everywhere - that might explain the squeak upon starting the engine.

[DARK AGE 53]

Popcorn, grinding and now you hear a squeak sound, which one is it......all of the above?

[2007yaris]

Popcorn when starting out - squeak upon starting - grinding when going - sorry for the confusion

[DARK AGE 53]

other then removing the serpentine belt to see if you can better isolate the problem I don't know what to add.

[2007yaris]

it's just odd to me - I have had many Toyota's with no problems - maybe wheel bearing?

[YarisSedan]

My only guess for popping would be detonation. Maybe you got a bad batch of gas even though extremly rare. Did you fill up your gas recently around the same time your oil was changed. You can try adding a fuel additive most of them act as octane boosters and see if that changes anything.

Otherwise removing the belts like others suggested and then driving it around the block for short distance to see if sound goes away can help isolate it. Do this only short distance since the water pump will no longer be spinning.

[2007yaris]

Took it to my local mechanic - can you believe this? A damn rock in the brakes - that explains why I heard it at only slow speeds - man!