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Matrix 2009 odd noise when accelerating

5.4K views 15 replies 9 participants last post by  abigmexican  
#1 ·
So, to try to make a long story short, a friend of a friend of my dad's moved to Mexico from the States and evidently, you can't register your out-of-country car there if you want to get a permanent visa -- or something like that. So he sold it very cheaply to my dad's friend who got quite a bit of work done on the car down there in Mexico and then sold it to me for my kids who are just starting to drive. The car was in worse condition than I was led to believe but I think I'll be able to get it up to snuff and it will be good enough for a 1st time car.

Here's what was done:
  • Front and Rear shocks and struts (KYB)
  • Front swaybar links
  • Rear trailing arm bushings
  • All 4 rotors turned and front brakes replaced
  • Front, Rear, and Front right motor mounts and transmission mount
  • Alignment
  • Transmission fluid and filter replaced

Anyway, halfway through my dad driving it up from Mexico to Texas he said it started to develop this loud grinding or vibration sound when accelerating. Once he got it here I took it for a spin and found that it does indeed make a rather loud sound and/or vibration but only during the initial takeoff/acceleration and only when given a decent amount of gas during takeoff, if you accelerate slowly it doesn't happen.

Some other things I've observed is that it doesn't seem to happen very first thing in the morning when it's cold (we've had some cold nights recently -- at least for Texas). It doesn't happen in reverse. The noise and vibration is very minimal if you let the car kind of roll forward on its own and then accelerate it doesn't happen or at least it's much more muted to where it's almost not noticeable. And it only happens when accelerating from a complete stop or if you are going under 5 to 10 MPH then if you accelerate VERY hard you will feel it but really just from a complete stop. Also it's really only noticeable inside the car, from outside it's much more muted and not very noticeable even with the hood up.

I took it to the mechanic I usually see and he couldn't find any obvious reason for the noise but he believes it could be that the motor mounts that were recently replaced are of low quality so it's excess vibration when accelerating but he can't say for sure. I also took it to my friend who, while not an expert, he does do all his own repairs for his family's 6 cars. He at first thought it might be the transmission slipping so we checked the fluid and found it to be the incorrect fluid so we replaced it with Toyota WS and will do it again next week. However, after playing around and looking around he now also thinks it may be low quality motor mounts but recommended I do some research before we get into replacing them with OEM as they are quite expensive.

I tried to record the noise but it came out way too muffled so I'm going to try again in the morning and will post that if it comes out better. In the mean time, I just wanted to see if anyone has any thoughts on what it might be and what to check? Or if anyone has experienced anything like this and if so if you ever found out what it was and how to fix it?

If if does seem to be the motor mounts is there a specific one or two I should start with replacing that would definitely help? I realize that it's best to use OEM but seeing as I don't have a lot of money to spend and these are already installed and while not good quality are at least new I'd rather only replace what I have too and what will make the biggest difference if that's at all possible -- at least for now.

Please forgive me if I went on too long. Thank you for any thoughts or ideas you may have!
 
#3 ·
Yes, I realize that now! By all accounts the mechanic was supposed to be very well respected by the expat community there so I kind is trusted that he was going to use decent parts and I asked my dad's friend to make sure he understood that. Also, my dad's friend is a very good person, well liked and respected by everyone that knows him. I realize that doesn't mean much when it comes to this kind of thing but what's done is done and I've learned my lesson for next time.

Thankfully I didn't spend too much on the car it was actually a fairly decent deal and if I can resolve this one issue I believe it'll be good enough for my kids for a few years until they can save for something better.

I guess my main question is now is that seeing as it appears to be the motor mounts Are there some that are more important than others and that I can get away with replacing one or two that would make the biggest difference and I can see if that helps with the noise and if so then do the others as well? I'd rather not spend $500 on motor mounts only to find out it's not the issue especially as I don't have much money to begin with. Does that make sense?
 
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#5 ·
I haven't tried that but can when I get home.

I did try putting it in drive and giving it a little gas while stepping on the brake and it's fairly obvious but I'm not sure if that's a valid test it any way.

There is enough vibration that you can feel it in your feet on the driver's side.
 
#6 ·
The mounts that sees the most work is the passenger side mount and the rear transmission mount. Drivers side mount under the air box would be important too, but is less robust compared to the transmission and passenger mounts.

Go OEM with the passenger and transmission. If you can find a good deal online, you might be able to afford all 5 mounts.

Consider it this way. If you buy an inferior set of mounts, chances are high that you will be replacing them again with in 24 months. OEM should get you around 3-5 years before becoming noisy.
 
#7 ·
Thank you that's very helpful! I do want to replace them all but I'll have to do it over time due to financial constraints so knowing which are most important really helps.

I thought there were only 4 mounts though: front, rear, passenger, driver ... at least that's all I see on parts.toyota.com. Where's the 5th?

if the car is in idle/neutral, can it replicate this vibration at approximately 2000 rpm ? It sounds like a heat shield vibrating to me
Tried this and there is no noise at all at any RPM.

So this is the best recording I could get with my phone. It really doesn't do it justice but it's the best I can do. I would say it's more of the vibration feeling than the noise but the noise is fairly pronounced as well. And it's more pronounced in the driver's seat than the passenger.

 
#8 ·
Thank you that's very helpful! I do want to replace them all but I'll have to do it over time due to financial constraints so knowing which are most important really helps.

I thought there were only 4 mounts though: front, rear, passenger, driver ... at least that's all I see on parts.toyota.com. Where's the 5th?
Sorry, I can’t count.
 
#12 ·
I haven't changed them but the mechanic said they looked good and actually in really good condition so I assume they were replaced at some point not too long ago. However, I will take a look at them and see for myself the next time I do work on the car and maybe make sure all the bolts are torqued correctly. Thank you for the idea!

I've had an odd rattle from the worn out foam weather strip where the air filter box slips into the air inlet tube. But it behaved differently from what you described, it was loud at idle and went away with acceleration.
Thank you! It's more like a heavy vibration than a rattle but I appreciate the idea and I will check it out just to be sure.
 
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#15 ·
We’re you able to figure out what happened?
Nope, never figured it out even though I had a few friends who are decent mechanics go over the whole car with me. One of those friends has a friend who is a mechanic and he was going to see if he could get him to look at the car but it never worked out and at this point, I don't think it's worth the amount it would cost simply to get it diagnosed much less fixed. My daughter and I are saving and hope to have enough for a different car in about a year so as long as it holds on until then I'm good. It's extremely irritating but what can you do. 🤷‍♂️
 
#16 ·
I have a 2009 Toyota Matrix XRS and the motor was shaking quite a bit. I knew it was a motor mount but to make sure I had my mechanic look it over. He said it was the rear mount is broken and $500 later it drove 90% better. Not sure if the replacement was OEM. Still unsatisfied I decided to replace the other 3. The drive side was defiantly broken as well. The next day I noticed a nose every time I took off fast. If you take off slow you do not hear the noise, only when you take off fast. This noise never happen until I replaced the left, right and front motor mounts. I knew I should have gone with OEM. Its one of these three and when I find out which one I will post again. Thanks for posting sam78.
 
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