Questions about my 2007 Prius!

Hi All,

I have noticed the past months (maybe for a while, probably picked it up just a few weeks ago) when I accelerate, I hear this grinding noise, but once I let go of the gas pedal, and slowly get back on it, the grinding noise goes away. To give a better example, when I step on the gas as I normally do, this grinding noise (it is coming from the front, I feel like it is coming from the passenger side, can't confirm 100%) but once I let go of the gas pedal, it goes away. The noise itself starts when I start picking up speed from a full stop, so when I am going at around 0-30 MPH I hear the noise, after that, I honestly can't tell (road noise may be blocking it off, not sure).

I went around the car and tires, and everything looks fine, I have no error codes thrown at me, thus, I am posting here as I really want to fix this issue as it is really bugging me. (It doesn't impact my drive, but that grinding noise is definitely not the normal sounds of a Prius).

Also another question - I originally got a wheel alignment on this car back in April, I had to go back to my mechanic (my mechanic does Prius work, and my parents have done their regular maintenance from him for years). For some reason, my driving wheel is slightly off to the right, when I go freeway speeds, I have to keep my cars steering wheel ~5 degrees to the right so it can go straight. It definitely goes straight once I leave it at that position, could this just mean my car just needs an alignment again? I was intending on going back to the same mechanic, bu was wondering on whether or not I should instead check out the Toyota Dealership (though, seeing these forums, people seem to avoid* them).

Anyways, appreciate any help here!

 

Yeah, there are no error codes, no hindrance in driving performance, nor MPG (I am averaging roughly 51 MPG, I have filled up around 14 times so far, since purchasing the car. I purchased the car itself back in March of this year).

The car currently has ~152,000 miles, my commute is 30 miles one way (so a total of ~60 miles for a day).

That being said, the only thing I had performed on the car was just a regular oil change (which was done myself) and an alignment, which was done by my mechanic. I had the mechanic inspect the car before I purchased it, and everything including the brakes were in great shape, but I guess my first start to diagnosing this "grinding' noise is from the tires, calipers?

That being said, does this sound like a serious issue? I understand we haven't determined what the cause can be, but getting a general idea of all the possibilities, is this something can impact the driving performance of the car?

 

That is a good question, to be honest, I don't notice the noise at all when turning, so I guess no?

I muted my music today for my commute, I am very confident it is coming around the front passenger area, and it goes away after I hit ~30 MPH. The grinding noise doesn't always happen, but when I am at a full stop, and than accelerate, that is when I hear it, but again, it doesn't always happen. I am assuming this is just something rubbing/touching in that front tire?

 

I will try my best to get a sound recording. I ran a Torque Test on the car just to make sure I didn't skip anything, while the car is not throwing any errors on me via the Dash, or the app, the test result just had something that came out red, attached a screenshot:

 

I had pressed the accelerator while the car was in park, the sound was totally normal, it just sounded like a normal Prius engine revving, which wasn't pretty loud at all. The grinding noise is only heard when the tires are moving, so I am assuming this crosses out something on the list of possiblities?

I will have a GoPro in the next couple of days, I will just try to put it as close as possible to the area where I hear the sound, and have it record my entire commute, but that is probably in the next few days. I may try to keep my phone's mic placed as close to the passanger side and have it record, not sure how effective it would be, bu worth a try.

 

So... today, I decided to check my oil levels. I honestly can't remember when was the last time I checked it, but I thought it wouldn't be too big of an issue since I had changed the oil back in June. Anyways, the oil level is very, very low. The car didn't give me any light about low engine oil, but it was seriously low, so I poured in some oil to the appropriate level. I will drive it again tomorrow, and see if that changes anything, no idea how the oil levels go to low, I am assuming the long commutes especially on a freeway burns oil faster than I thought? There are no leaks, everything is dry underneath the car when I jacked it up.

 

I want to say roughly ~2,400 miles since last change? I do drive 30 miles each direction 5 days a week. Though, I usually drive slow, especially on the freeway as I try to get as many MPG's as I possibly can. The weird part is that no indication light or anything came on, so I have no clue why the car itself didn't warn me. I honestly can't say exactly how much I filled, but I used the remaining oil from the last oil change and poured that in, I want to say it is now half way full? I am definitely going to do an oil change this weekend.

The car does average a total of ~51 - 53 MPG's per each fill-up, so no idea whats up here.

This is kind of getting me nervous now...

 

The oil level was very close to the dimple. The bottle didn't have a measurement line that told me how much oil was left in the bottle, but I can assure you that from the dipstick, it reached pretty close to the half-way of the low and high marks on the dipstick.

My only reason for possibly changing the oil is just to keep a close monitor of the oil fluctuation this time around. I can go ahead and continue adding it, but I figure doing a change now would teach me my lesson of keeping a very close eye on the fluid levels of the car, unless it is just counterproductive doing so.

The 2,400 mile mark is my approximation, I am currently away from the car, but I reset the Odomoter trip reading every time I change my car, I can post that once I am back with my car again.