Rattling sound during acceleration

[bail]

Car is running smoothly at first but once it gets hot or if the car stays on the road for more than an hour ive notice rattling sound from the hood everytime i step on the gas pedal. Car although does not lose power but the sound is annoying. Theres no sound when the car is idle. Cant seem to find the cause of it. Im using corolla 1997 gli 1.6 with 110k mileage. Please help. Thanks

[oj88]

I put my money on engine knock.

If it is, there are a number of possible causes:

1. Your fuel octane may be lower than what the engine needs
2. Ignition timing too advanced
3. Carbon buildup in the combustion chamber
4. Wrong air-fuel mixture (ie. Too lean)
5. Cooling system issue, causing hotspots in the cylinder (related to #3)

Not sure if your vehicle already has an ECU. But if it did, it may also be a problem with the computer (though, unlikely) or the knock sensor (somewhat more likely).

[jasonub]

Gas up with higher octane mga 93 or 95 is better. Then report back. Mura na gas

[vinj]

Agree that it may be detonation.
1. When was the last time you tuned up your engine (change spark plugs and check timing)?
2. What fuel do you use?

[bail]

Been using premium ever since. Nagpatune up na rin ako, ecu and change of spark plugs last november 2014. Masisira ba ang car if hindi to naayos?

[dr. d]

Been using premium ever since. Nagpatune up na rin ako, ecu and change of spark plugs last november 2014. Masisira ba ang car if hindi to naayos?

if it is indeed engine knock, yes. masisira ang makina.
errr... was it an intelligent tune-up, po? or was it done by the friendly by-the-ear neighborhood PUJ mechanic, who guessed more and measured less..?

[sirkosero]

How did they "tune up" the ECU? Afaik di pwede ito unless may programable ECU ka.

Change gas ka lang. Okay na yan at palitan mo mekaniko mo kung nag "tune up" sya ng ECU mo

[vinj]

Been using premium ever since. Nagpatune up na rin ako, ecu and change of spark plugs last november 2014. Masisira ba ang car if hindi to naayos?

November 2014? How far has the car traveled since then? You should get a tune-up perhaps once a year if you don't rack up high mileages. Before, i'd check the timing and spark plugs (if using copper tipped) every 10,000kms.

Have the MAF sensor cleaned also.

[pdspd]

Nka MAP(manifold absolute pressure)sensor po ang 4AFE,iba ang MAF(mass air flow)sensor.Tama ung mga advise na nauna.Fuel knock or tope yan.Pag mainit,umaakyat or sa traffic mo e2 maririnig.pacheck mo ung timing sa may timing light na nka diagnostic stage ang ecu.tapos 95+ octane rating.Try mo muna haluan ng octane booster gas mo.available sa ACE or sa mga suking auto supply.

[jick.cejoco]

errr... was it an intelligent tune-up, po? or was it done by the friendly by-the-ear neighborhood PUJ mechanic, who guessed more and measured less..?



The case of the bind leading another blind person. The Scientific Wild Ass Guess (swag)