Going off of what you described, it could be pinging, meaning the timing is too advanced. It won't ping on decel or higher rpms.

 

Sounds like the shop messed up.

Have I done any damage by driving around with this pinging over the past month?

 

No, I advanced my timing before to see if it helped with mpg and throttle response, had it like that for awhile but it didn't really do anything but make noise. If it's making the sound and then let off gas quick does it stop? If it doesn't it's not pinging.

 

Letting off the gas stops it immediately, as in the video.

I will take it back to the shop tomorrow.

 

If the shop did the timing belt and accessories, they shouldn't have touched the distributor. To adjust the timing you have to loosen the two distributor bolts and turn the distributor. If I remember, counter-clockwise advances it and clockwise retards it.

When my car was pinging, anytime the revs were below 3k and I floored it, it would ping like crazy. Sounds like somebody crumpling a soda can.

If you can put your trans in 2nd gear probably around 30mph and floor it, see if it does it.

 

I have a 3-speed automatic, so if I floor it in second, it'll downshift to first and the noise goes away. The noise gets loud but sounds more like a squeaking.

It sounds similar to this video.

 

Will it downshift even if you move the shifter to "2nd"? I wouldn't think so, but it might. If you can look at the front bottom of the distributor, where the first bolt is; see if the bolt slot it at the edge. Normal timing is somewhere in the middle, and if it's turned all the way in a direction it's not right.

 

Yes it will, the 2 position only locks out third gear. I will check tomorrow morning.

EDIT: I will check right now.

 

The chip the shop made has not moved since August (below).

Timing has not changed. Could the noise be anything else? The tensioner pulley perhaps?

 

Is it possible that it has always been making the noise, but you just noticed it because it was worked on? I do that sometimes when I listen to make sure everything sounds right. Otherwise the timing is probably okay.

 

That's possible. I have past recordings of the engine, so I'll listen to those.

 

If it made the noise when the transmission downshifted, could you still hear it physically? Because it could still be making the noise and you just can't hear it because of the engine. Which could be a wheel bearing.

You can check the wheel bearing by jacking the suspected wheel up and putting you hands opposite from eachother diagonally on the wheel. Rock it back and forth and feel for play, there should be very little to none.

 

I can't say for certain because the change in volume is significant.

I eliminated the wheel bearing as the suspect when the noise persisted after a tire rotation. There is little to no play in any of the wheels.

Maybe the timing was slightly changed when the distributor O-ring was changed, just before the August photo was taken with the chip, and I didn't notice it.

 

I don't see how a tire rotation eliminates the wheel bearing. Changing the wheels doesn't move the wheel bearing.

 

For some reason it won't let me edit my old post on mobile so excuse this double post.

Otherwise if it's not the wheel bearing I can't say more without seeing or hearing it first hand. I would just be guessing otherwise. Someone with more experience can chime in.

 

I was under the impression that wheel bearing noise changes after a tire rotation. I am probably mistaken. Thank you for your help.

I think you're right. Pinging frequency would go up with engine RPMs, while this noise rattles independently. It is probably the front left wheel bearing.

 

While rotating tyres may change the sounds of bad wheel-bearings, it's not a 100% diagnosis. That's because not all the wheels are balanced the same and not all the tyres are same out-of-round amount. So when you rotate tyres and the sound may or may not change, the wheel-bearing can still be bad, just that it's not being agitated as badly by a wobbling wheel.

Also bad wheel-bearings shows up as shuddering under braking well before you hear noises. Does your front-end shake when you get on the brakes? Does the noise change between coasting and braking?

I suspect that the ignition-timing may be off and causing knocking & pinging. Sounds like shaking popcorn kernels in a coffee tin. Even though the distributor position is the same, if the belt is off by one tooth, that will change your ignition-timing. Verify with a timing-light.

Long-term knocking & pinging can cause irreparable damage. Melted pistons, cracked rings, scored cylinders, burnt headgaskets. Check your ignition-timing with a timing-light. They're dirt cheap and is a good way to double-check a shop's work. That's how I got started with doing all my repairs; about 50% of timing-jobs came back with problems when I had shops do it.

 

Also bad wheel-bearings shows up as shuddering under braking well before you hear noises. Does your front-end shake when you get on the brakes? Does the noise change between coasting and braking?

Not at all.

Check your ignition-timing with a timing-light. They're dirt cheap and is a good way to double-check a shop's work. That's how I got started with doing all my repairs; about 50% of timing-jobs came back with problems when I had shops do it.

This is embarrassing, I don't understand how to check the timing. The Haynes manual says this:

(1) Connect a tachometer according to manufacturer's specifications (Do I need to buy a tachometer?)
(2) Locate the diagnostic connector and insert a jumper wire between E1 and TE1 (What is a jumper wire?)
(3) Connect the light, find the timing marks on the front cover, let the engine warm up, and the mark on the crankshaft pulley should match up to the 10 degree mark on the timing scale (where are these marks?)

 

I couldn't really hear anything in the video and this probably isn't the problem you're having, but I had a 1993 3spd Corolla which made a squeaking/Whining/Grinding noise when my differential fluid ran low. I had just done brake work so I assumed it was maybe a dust shield touching or possibly just squeaking breaks or bad wheel bearing.

 

I haven't checked the differential fluid, but I have not seen any leaks and I changed the fluid a year and a half ago.

I bought a timing light on the way home from work today, and I discovered that the notch shows up here when the engine is fully warmed up and the inductive connector is attached to the left-most spark plug wire looking from the front.

I did not connect any jumper wires. If I need one, where can I get one?

 

Good job! You're halfway there. To jumper the terminals in the diagnostic connector, just use a piece of wire or straighten out a paper-clip into U-shape:

 

I used a paper clip. The check engine light started flashing, but I assumed that was expected. The notch moved to here (red mark):

The timing is wrong. I expect this is the source of the popping sound.

How did the timing change? The mark on the distributor didn't move.

 

Timing belts stretch over time so if the ignition timing was set when the old belt was installed putting on a new belt will change the ignition timing. Just set it to factory spec and see what happens.

Does the engine run decent otherwise? Good power doesn't feel gutless?

 

Good power. I don't know how to set the timing, I'll give it back to the shop tomorrow.

EDIT: Could my cam timing be off too if the timing belt was sloppily installed? How can I tell?

 

I believe it would barely run or run very bad if the belt was off a tooth.

 

So my conclusion is that the new timing belt is tighter, so it changed the ignition timing that was set correctly with the old looser belt.


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You're 2-minutes away from fixing your problem. Loosen the bolt that adjusts the distributor (and the pivot bolt on other side).

Rotate the distributor while watching timing-mark to set it to 10-degrees BTDC. Then carefully tighten down distributor being careful not to move it.