Toyota Nation Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
Hello friends!

I'm hoping to tap into some advice for your experts on a weird vibration coming from my engine bay. A description below and a video link at bottom.

When I start my cold engine and shift into D or R in my '05 Corolla CE, I notice a low-pitch vibration coming from the engine bay. It sounds like it's coming from the serpentine belt; however, even after I changed the belt, it continues to make the sound.

The noise occurs after a cold soak start, particularly from spring to fall when the outdoor temp is colder than 10 degrees C (50 Farenheit). The vibration does not occur when in P or N, perhaps due to the higher idler RPM in these hears. It occurs only in D or R, and only at RPMs of ~700-800 such as when coasting at low speed or when waiting at a light. The noise goes away when the engine warms up, typically after ~2 minutes.

I've noticed the sound for years, but in the last year it's become noticeably worse. Given that it sounds like it's coming from the serpentine belt area, my suspects:

Water pump: I removed the serpentine belt and noticed a little bit of play in the water pump bearings; however, I have no rad fluid leakage or any evidence of a failing pump

Idler pulley: with belt removed, I hand-spun the idler pulley and it seemed to spin OK.

Tensioner assembly: Seems to be applying a good amount of tension; no obvious oil leakage or visible damage.

Since the idler pulley and tensioner assembly are expensive ($150) I was hoping to replace those only if I was pretty sure they were the culprits. Thanks in advance!

Video of cold soak start:
 

·
Super Moderator
Various Toyotas
Joined
·
5,367 Posts
Could be a number of possibilities. If you can verify that the tensioner is bad, you can get an INA brand tensioner for about $68USD on Rock Auto (use the TN 5% discount code). INA is the OEM tensioner for the Gen 9 Corolla. INA part #FT40016

I would check motor mounts. There's one on the passenger side at the top and there's one behind the battery on the driver side. Another one at the front center of the vehicle near the bottom of the radiator and another at the back of the engine underneath. If you have any bad mounts, my guess is they all are bad or are about to go bad. I strongly recommend OE Toyota mounts for the passenger and driver sides. You can get away with medium quality Beck/Arnley mounts for the front and rear (but if you can afford it, get the OE Toyota mounts for those as well).

I would also check your exhaust manifold where it connects to the front of the exhaust pipe. You can spray it with kids' bubble solution and raise the RPMs. If there's a leak you will get some nice bubbles.

Some people will remove the serpentine belt and run the engine just for a minute to see if the noise/vibration goes away. If it does, you've come closer to isolating the issue. The serpentine belt runs the water pump, power steering pump, alternator, and A/C compressor. No harm will be done if you run it just for a minute without a belt.

Do you have any check engine light codes, like the P0171? That one occurs when the weather turns cold. It is fixed by replacing the intake manifold gasket with the improved/updated gasket from Toyota (the improved gasket is orange in color).
 
  • Like
Reactions: kevcules46

·
Registered
Joined
·
13 Posts
Discussion Starter #3
Could be a number of possibilities. If you can verify that the tensioner is bad, you can get an INA brand tensioner for about $68USD on Rock Auto (use the TN 5% discount code). INA is the OEM tensioner for the Gen 9 Corolla. INA part #FT40016

I would check motor mounts. There's one on the passenger side at the top and there's one behind the batter on the driver side. Another one at the front center of the vehicle near the bottom of the radiator and another at the back of the engine underneath. If you have any bad mounts, my guess is they all are bad or are about to go bad. I strongly recommend OE Toyota mounts for the passenger and driver sides. You can get away with medium quality Beck/Arnley mounts for the front and rear (but if you can afford it, get the OE Toyota mounts for those as well).

I would also check your exhaust manifold where it connects to the front of the exhaust pipe. You can spray it with kids' bubble solution and raise the RPMs. If there's a leak you will get some nice bubbles.

Some people will remove the serpentine belt and run the engine just for a minute to see if the noise/vibration goes away. If it does, you've come closer to isolating the issue. The serpentine belt runs the water pump, power steering pump, alternator, and A/C compressor. No harm will be done if you run it just for a minute without a belt.

Do you have any check engine light codes, like the P0171? That one occurs when the weather turns cold. It is fixed by replacing the intake manifold gasket with the improved/updated gasket from Toyota (the improved gasket is orange in color).
Thanks so much for the quick reply!
My check engine light is not on, so I don't think that's the issue.

Removing the serpentine belt is a good idea. If I was to remove the belt, move it into D and heard no noise, would that likely narrow it down to the water pump, power steering pump, alternator, and A/C compressor and possibly also the tensioner? In other words, it would rule our the engine mounts and exhaust manifold, right?
 

·
Registered
Joined
·
13 Posts
Discussion Starter #5
Motor mounts
Thanks for your feedback. The other gentleman who commented suspected the same.
Is there a way I can diagnose it conclusively so as to rule out the other systems (water pump, idler pulley, alternator, etc)?

Anything I should be looking for on the mounts? I took an initial look and nothing stood out.
 

·
Administrator
2006 Corolla XRS
Joined
·
10,992 Posts
When mounts start to vibrate, it's typically intermittent. Until the material can no longer isolate, then it makes the metal to metal contact. The insulator won't last forever.

Just take a closer look. The passenger side mount is the one that takes the most weight. In order to inspect it, you have to remove it and flip it over. Or use an inspection mirror.

I'm just throwing out ideas for you to get an idea of where to look. You don't necessarily have to listen to me. It won't bother me.
 

·
Super Moderator
Various Toyotas
Joined
·
5,367 Posts
Removing the serpentine belt is a good idea. If I was to remove the belt, move it into D and heard no noise, would that likely narrow it down to the water pump, power steering pump, alternator, and A/C compressor and possibly also the tensioner? In other words, it would rule our the engine mounts and exhaust manifold, right?

Also, if it was motor mounts, wouldn't the vibration occur at all temperatures, rather than just when it's cold?
I don't think the water pump, alternator, etc would be the culprits as long as their pulleys are spinning freely, but removing the belt and running it for a minute when the engine is cold might help you focus on the tensioner and belt being possibly problematic. I'm assuming your A/C compressor and defroster were turned off when this video was made?

I can see how a mount can act up when it's cold and then ease up when it's warm. Same thing for the exhaust.

You said that you took an intial look at the mounts, but I don't know what that entails for you. You need to inspect the rubber of the mounts. Look for obvious tears, but also look for cracks and dry rot. You can feel under the passenger mount at the bottom. It should not be lumpy. You can inspect the driver side mount by removing the battery which will give you a view of the front of the rubber. Crawl under the front of the car to inspect the front mount. The rear mount is hard to see, but you can take a look at it by removing the driver side front wheel. You can also get up on the engine with a flashlight and look down at the rear mount.
 
  • Like
Reactions: 75aces

·
Super Moderator
Various Toyotas
Joined
·
5,367 Posts
Here's what I mean by "lumpy" for the bottom of the passenger mount:

315182
315183


And here are examples of cracks:
315184
315185


New one (Beck/Arnley brand, which is medium quality) looks like this:

315186
315187


Here is a messed-up driver side (transmission) mount on the left. Photo on the right shows broken mount compared to new Toyota OE mount:

315188
315189
 

·
Registered
Joined
·
492 Posts
In additon to what has been suggested above. Take a look (if you can) at the exhaust heat sheild as well to rule it out as a possible cause. I had a weird rattle that was only noticible while the vehicle was parked. Turned out a piece of the heat shield rust off and got wedged. Took a mechanic a few minutes to track down the sound, then with the car up on the lift pull it out from up near the engine bay.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #11
Here's what I mean by "lumpy" for the bottom of the passenger mount:

View attachment 315182 View attachment 315183

And here are examples of cracks:
View attachment 315184 View attachment 315185

New one (Beck/Arnley brand, which is medium quality) looks like this:

View attachment 315186 View attachment 315187

Here is a messed-up driver side (transmission) mount on the left. Photo on the right shows broken mount compared to new Toyota OE mount:

View attachment 315188 View attachment 315189
Thanks again so much for this input and photos. I am blown away at the level of expertise and valuable feedback on this forum. :)
 

·
Registered
Joined
·
13 Posts
Discussion Starter #12
In additon to what has been suggested above. Take a look (if you can) at the exhaust heat sheild as well to rule it out as a possible cause. I had a weird rattle that was only noticible while the vehicle was parked. Turned out a piece of the heat shield rust off and got wedged. Took a mechanic a few minutes to track down the sound, then with the car up on the lift pull it out from up near the engine bay.
Thanks bennor, good suggestion. May as well rule out the simple fixes before dropping more serious cash on engine mounts. Cheers and have a great week.
 
1 - 12 of 12 Posts
Top