Engine Noise Under Load

[William]

just wondering if you might be able to tell me a little more about this engine noise i am getting when driving the my 1990 Toyota Corolla 1.3(2E). its done nearly 300,000ks.

Basically my question is, what sort of knocks or rattles would you get when putting an engine under a bit of load.

i get the usual rattle when i start the engine from cold, that disappears after a second or 2.(top end?) I dont get any other knocks or rattles at idle

Its fine if i dont put my foot on the accelerator too far but when i put the engine under a bit of load or strain it gets what doesnt really sound like a big end knock but it doesnt sound like a top end rattle either.

any ideas??

Topic

[Jamie]

When you say knock do you mean as if someone is hammering on something hard, or more a “tink, tink” kinda noise that goes away as soon as you let off the accelerator?

youtube “engine ping”. Is that similar to what you’re hearing?

The initial noise on start up is more than likely the lifters. It can be a sign of a few things. Oil is low/worn out, the lifters are dirty and some oil cleaner and oil change is due, or they’re worn out. If the noise goes away after starting up and stays away while driving I wouldn’t worry yet.

[William]

Its not dull like a knock, but its a little bit more high pitch.

Lifters are definitely old so im not to worried about the start up rattle.
Do you think the lifters would make no noise under light acceleration but make all the noise when you put your foot down?

[Paul]

Sounds like detonations for me

[valde]

Two times I have looked at similar sounding problem. First was Nissan with ga14s it sounded like bottom end sound if you used torque. RPMs didn’t matter. Problem ended up being one small broken vacuum line. No idea what that vacuum line was for. Next was Toyota with 4a it sounded more like top end sound but only at higher RPMs and using torque. Problem ended up being exhaust manifold gasket.

[Tom]

My first guess would be detonation. It can be (and often is) caused by a vacuum leak somewhere. Go over all the rubber vacuum hoses carefully, listen for a hissing, or whistling sound when the engine is running, and if that fails, spray a mist of slightly soapy water over any and all possible sources of vacuum leak, while listening for a slurping sound, and / or change in idle.

[Paul]

Does the car burn oil? Detonations could be also caused by the carbon residue that is created by burning oil. I would try using a higher octane fuel (if available). If this helps, your problem is detonations. If it doesn’t, it still might be and might not be detonations.

Correct me if I’m wrong

[William]

Thanks for all your help with this everyone. I have spoken to my mechanic (the one i use when my car isnt a pile of crap) and he has told me that detonations are actually quite common with this type of engine in NZ.

I dont have a timing light so ill take it to him tomorrow and he can make sure that the timing is right.
He also mentioned vacuum leaks and mentioned a few good places to start looking!

Thanks again

[EricTheCarGuy]

It may be timing related if the timing belt is old. As they get old, the stretch a little. When this happens it can cause engine noise. There’s more information on finding the cause of noises like this in this article. Keep us posted.

http://www.ericthecarguy.com/faq/diagnosing-noises-in-your-car

[William]

I seriously don’t understand how you find the time in the day to answer things like these this amongst everything else you must be doing, what a legend.

No matter what we did with the timing on the dizzy we couldn’t get it right. I guess the timing must be out on the belt by just a tooth which is a pain, I’m thinking it probably just wasn’t put back on correctly… by me. Good news is we got it running pretty good and it will be sufficient until the timing belt gets changed (soon)

Thanks again!

[Author]

Replies