Rhythmic Thump

[YarisSailor]

I've been having an issue that I can't seem to figure out the cause of yet to fix it. It's a 2010 Yaris hatchback 3dr. Manual. Just shy of 70k on it.
Anyways. Had an alignment issue for a while which I just recently got the alignment done and replaced the tires because the old ones had noticeably uneven wear (were very loud). Now that that noise they were causing is gone I can fix other issues that I'm noticing.
Anyways here's the issue:
When driving straight or turning I notice a rhythmic thumping that is speed dependent. The rhythm matches my speed, rather than being constant. Anyways it's louder at slow speeds and definitely more noticeable when rounding bends on a road at a slower speed.
Troubleshooting I've done already. 1. After new tires I noticed the thumping so I got the alignment redone. 2. Took it in for a full steering and suspension evaluation. They said everything looked fine and couldn't recreate the issue. Then had me drive with the mechanic and STILL couldn't recreate the issue. Then after I left, I heard it again. It's mostly noticeable when rounding a bend slowly, not necessarily just turning. And then when driving straight at highway speeds.
Any ideas, I've looked up the symptoms on google a million times but can't seem to find anyone who's having the same issue where the problem isn't something I've already checked.

[Bluevitz-rs]

It could be a bad wheel bearing. But they're usually more of a droning sound.

Also could be some rust buildup inside the brake drum or rotor. I get that once in a while and have to take them off and chip it off.

[YarisSailor]

The mechanic said the brake discs did look, not warped. He said they just looked pitted (I lived in maine the past two years, they use ALOT of salt in winter) by he also said the same thing, that it could be a wheel bearing. I know what a bearing sounds like when it's droning but I've never experienced one going bad and causing a thump. Maybe I'll change my brakes out a few thousand miles early and see how it works. Luckily I've done a brake pad, disc, and drum changeout before (albeit on a Volvo 850 with a Hanes manual in hand which I can't find for a Yaris). But I've never done a wheel bearing replacement before and I can't tell which side it's coming from very easily to know whether I should change out driver or passenger side to correct the issue.

[dogsridewith]

One tire might be balanced but not round...tire imperfect or flat spot on rim. I bought 71 Beetle from a friend who replaced everything in the front end and never solved shake. Fixed by me getting a balance check and seeing one of the wheels was wobbly.
My new-to-me Yaris was thumping on the test drive. Found 49 psi in the front tires and great mechanic noticed a not severe flat spot on one of the stock rims. Hit w/ hammer before installing new tires. Couldn't be smoother driving.

[alanwagen]

Likely a tire, they do get out of round. Especially if they have ever had a nail. Sometimes that causes the belts to slip, thus our of round. You could rotate your tires and see if the sound moves.

[YarisSailor]

So, check the rim for any flat spots? I've never had a nail in these tires, they're brand new (maybe 100 miles on them). And then get a balance check. Worst case, replace the rims. Best case knock out a dent?

[dogsridewith]

problem is--you have to watch the wheel spin on the balancer to know it was correctly observed...but most shops will tell you their insurance won't let you in the garage.

(If I were a young fellow, I'd open a tire-install shop with rim cleaning and tread shaving. And customer-watch possible, somehow. Other thing typically not done is removing thick cake on the inside of the rear rims...then some of the cake gets hit w/ a spray wand or stick and you're out of balance.)

[nortonfb]

Put in neutral, try coasting and a turn and see if that effects the noise.
You can try rotating the tires and see if there is any difference in sound.

[dogsridewith]

Do you feel the thump, or just hear it?
also: the out-of-round or balance symptoms I've had didn't show at low speeds/turns/corners. Except sometimes the out-of-round, where at a low speed the whole cab seems to bob along.

CV joints?

[YarisSailor]

I mostly hear it, except sometimes at slow speeds I can feel it a bit. its definitely more noticeable at lower speeds and becomes more noticeable the more I slow down if I'm on the highway.