Yaris Sedan 2008 Engine vibration

[seatech30]

Hello Everyone,

I've been dealing with this problem for over 30kmiles. When it first started it would only happen while the car was stopped on an incline/slope. Now it does it even when the car is on flat road.

I've replaced battery, spark plugs, cleaned throttle body and MAF with corresponding cleaners, cleaned engine filter, ran injector cleaner through fuel tank twice (BG 44k), and replaced 2 motor mounts. Yet it seems to be getting worse. I have 192kmiles now, and I first began to notice the problem around 30kmiles ago.

I've even tried a different MAF and nothing. I'm currently considering the possibility of a bad timing chain tensioner. I used a timing light on the crank shaft bolt and can see the bolt "shift" position as the car is revved. Is this normal?

Any help will be greatly appreciated, thank you!

[WeeYari]

Are you pressing hard on the brake? I notice my engine will shake if I'm only applying enough pressure on the brake to hold position. Press down a little harder and the shake stops.

[seatech30]

Hi WeeYari,

Thanks for the reply. Actually the vibration can be felt more the harder I press the break. When I let go of the break, I don't feel it as much, but I can hear the car almost rattling. When idling, you can observe the engine moving back and forth quite a bit.

[invader166]

I think we need more information to better help you.
Is your car a manual or automatic?
Can you tell us more about this crank bolt "shifting"?

[dogsridewith]

Did all the replaced plugs read the same? The new ones?

[seatech30]

Ah yes, it's automatic 1.5L I think.

The crankshaft pulley bolt seems to be steady while idling. Meaning it doesn't look like it is varying position in sync with the light timing gun. However when I rev up the engine, the bolt position seems to change ("shift" degrees) I can take a video of this tomorrow if I get a chance. However, I'll be out on vacation for two weeks tomorrow noon.

As I'm sitting here in the drive thru my car feels like it's gonna rattle itself apart.

Yes, all the plugs were checked by myself with a wheel and were pretty much the same. The vibration was still in place prior to this though.


The vibration seems to cease a bit when I take off from idle, but now I can feel the vibration as I'm entering the freeway.

Thanks again for the replies.

[WeeYari]

This is all a little too vague for any meaningful help to be provided. At this point all people can do is to point you in many different directions. If this thing is truly getting worse, probably should just suck it up and see an mechanic. You've already thrown significant money at random stuff with no resolution. Stop the madness as Kevin O'Leary is fond of saying.

[seatech30]

The motor mounts were replaced by a mechanic who said it would solve the problem. But it actually made it worse because the engine now has a better hold on the car and the vibration transfers even more.

I've spent more money listening to mechanics so far than I have trying out my own thing.

I don't understand how this is vague. There is vibration coming from the engine, that is audibly and visually noticeable. It is more pronounced when the car is stopped at idle. When the engine is rev'd up, the vibration ceases a bit. At freeway speeds it becomes noticeable again like a hum almost.

I understand if you're not familiar with this issue and I appreciate the feedback. I'd like to hear from anyone on here who has used a timing light on their crankshaft to see if they see the same thing I see.

[kevinj93]

The timing will change depending on engine speed and load.
As the engine spped increases you should see the riming advance, so the crnk pulley/bolt will appear to move "backward" compared to the directiom of rotation.

If you blip the throttle, you wil mpossibly also see the timng momentarily retard as the engine picks up revs.

[dogsridewith]

By "reading plugs," to give some indication of the degree that 4 cylinders are working the same, I mean color, oiliness, crust, dust etc. various places on the plugs exposed to combustion products.

[tmontague]

Based on your original post and what you've done so far I am pretty confident that it is a vacuum leak somewhere.

It gets worse when you depress the brake which likely has to do with the brake booster being connected to vacuum.

Easiest way to figure this out is buy a OBD reader that will show fuel trims or go to a mechanic who has one. If at idle your long term fuel trim is reading a high positive percentage (>5%) then you likely have a leak. If you then rev the engine to 3k rpm and hold it there the numbers should then go closer together (closer to zero).

I'm blown away no mechanic looked at this yet considering how much money you've already thrown at the car with no proper diagnosis.

The CEL will only go on if the fuel trim goes about 20% for a short period of time. However for the Yaris to idle rough it doesn't need to trigger a CEL.

EDIT* Just noticed your car does this while driving as well? Likely not vacuum leak then, but I'd still look into it to rule it out. FWIW the timing will shift when the engine is revved that is normal

Other way to check for a vacuum leak is to light a stick of incense and park your car in a non windy area like a garage. Run the car and hold the stick over and around the intake area. Watch and see if the smoke starts to get pulled or influenced in any area.

I had the same issue as you when I installed my oil catch can as it had an open valve on the bottom I didn't know about. The CEL would only go on when idling for more than 30 mins like when I'd go across the border and sit in traffic.

[Bluevitz-rs]

I'm guessing low compression on one or more cylinders. My old engine ran fine, got decent mileage but idled rough. Cylinders 2 and 3 had lower compression than 1 and 4.

[seatech30]

Dogsridewith, all plugs looked the same. A bit of carbon, but nothing out of the ordinary. I'll pull out the new ones and check them when I return.

Kevinj93,tmontague,Bluevitz-rs, thanks for the great info and suggestions. I'll see what I can do about checking vacuum.

It's hard to find a good mechanic. I've recently moved too, so hard to choose a new one. But I'll definitely use this new information as a guide.

Thanks again!

[dogsridewith]

Friend has a same-era Corolla, dealer serviced and clean w/ +100k miles. Running problem(s) traced to bad gasket between head and plastic intake manifold.

[seatech30]

Finally got around to replacing the final mount (transmission) and the vibration got worse. Now (using a sprectrum accelerometer app) I can see that the frequency of the vibration increases with RPM (even while in park.) If the RPMs get anywhere near 4k I can hear what sounds like booming. When I'm at highway speeds I can hear this booming sound if i'm going fast enough as well, quite annoying.

tmontague, I tried logging my trims. The long term starts at -7% and as I go up slowly to 3k rpm it goes to -1.56% then -2.35% and as I slowly rev down it dips to -0.78% but bounces back to -7 around 1krpm. I did this twice while dark outside after I got home from work and I swear my headlights and dash lights blinked off for a split second each time when revving down at around 2krpm. Kind of weird.

Is it safe to say since the vibration frequency is tied to the rpms that this is an engine issue? I really am suspecting something is wrong with the injectors even though I did a listening test and they all seemed to be ticking about the same.

[KimmoKekki]

Alternator 1 point to try !
Take belt away and fire up ...

[tmontague]

Hmm a -7% trim could easily be a small exhast leak. That said it shouldn't and likely would not cause your issue.

Not really sure at this point tbh

[jcboy]

Imho vibration without dipping idle would be due to bad engine support/s. More likely just 1 of them is bad. If it were an old civic id say the center one near the firewall, if that makes sense

Sent from my G9208SS using Tapatalk

[seatech30]

tmontague thanks for the help anyways and thanks to everyone else too for the suggestions.

I tried taking the serpentine belt and still vibrated. I was changing my oil and was looking around and didn't see anything odd. I tuened the car on and was feeling around I noticed that the back mount (closest to the inside of the car) was stable from below, butvibrated above the joint. The right mount vibrated on both ends. Couldn't do this check on the tranny mount. Now in curious if the back mount is no good. It clearly is new though.

I'll have to find a knowledgeable mechanic, and will report back if and when I find the cause.

[sherlockholmes]

I wonder what happened to OP, because I'm having exactly the same problem with my 09 AT. It's making me mad.

[sherlockholmes]

I wonder what happened to OP, because I'm having exactly the same problem with my 09 AT. It's making me mad.

UPDATE:

The problem was passenger side front engine mount. Put it up on jack, noise was gone. Replaced the engine mount with used older one from a guy who sells used parts. It's now running smoothly. The engine mount from 6 months ago failed, it was not OEM. Crazy how important engine mounts are. Also realized bigger engine make the mounts fail quickly, as I changed from 2NZ-FE to 1NZ-fe.

[IndestructibleYaris]

Mine was a loose belt. It would rubber band with the engine damper on the crank pulley or something and it really rattled the car under heavy electrical load. I replaced the battery and tightened the belt tension at the alternator. This fixed my vibration