Yaris is shaking :(

[33OH]

Hi all,

I have an '08 Yaris, 130k miles, manual trans, with a vibration - even at idle.

No CEL, and it doesn't appear to be missing.

I thought motor mounts, so I went ahead and replaced every single one, including the motor to tranny dogbone mount.

Still shaking, even worse now that I've replaced motor mounts (but probably because these are tight now with no tolerance for vibration.)

Any ideas on what to check next?

[Sir A.Y. Atoyot]

Possibly one of the plugs isn't firing properly due to a coil or wiring issue. This would likely show up on a proper Toyota dealership diagnostic session - maybe expensive.

[33OH]

I do not believe it a misfire, but I did look into it at first. Also just swapped in new plugs just in case.

Thanks for the response!

[racerb]

I thought you were selling this car? If it has issues, how much cheaper could I get from you now??

racerb :laugh:

[33OH]

I was a few months ago (before it had issues) when I had my Subaru. Sold that and kept the Yaris.

[racerb]

Good man, the Yaris has most likely got a simple issue, maybe even a coil-pack breaking down. At 130K, things like that can start to happen, it's pretty common!

racerb

[xnamerxx]

Check the o2 and MAF sensor.

[dragoonmc]

Did you recently disconnect the battery?
I did that last night and noticed it shaking bad at idle now and in didn't before but I kind of remember it doing this the last time I disconnected the battery and expect it to get better soon

[CTScott]

Did you recently disconnect the battery?
I did that last night and noticed it shaking bad at idle now and in didn't before but I kind of remember it doing this the last time I disconnected the battery and expect it to get better soon

If it doesn't get better quickly on its own, then clean the throttle body. There is a TSB about rough idle after disconnect where the solution is to clean the carbon deposits from the throttle body.

[racerb]

CTScott may be right on the money on this one, my old Rav4 used to do that until I cleaned the throttle body and MAF sensor, but be very careful with the MAF it's pretty delicate!! Worst part on the Rav, was it would actually cause the throttle butterfly to stick making taking off from a stop worse than the FBW hesitation!!

racerb :redface:

[33OH]

Thanks Scott, I'll check the throttle body out. I remember it had some salt deposits on it anyway, so it's a good place to start. MAF was pretty damn clean, just had it out, so I'll check the TB first.

[CrankyOldMan]

I'm thinking I may be in the same boat: rough idle, stalling when coasting to a stop, frequent P0171, RPM hunting, etc. My thought is that the PCV is dumping an awful lot of oil back into the Blitz intake tube--it was wet the last time I pulled off the hoses. Perhaps time for an oil catch can...

[33OH]

I did have the P0171 in my code history, but it's not throwing the code now. May be completely unrelated.

I'm not having any oil inside my intake tube though.

[justjesus]

check for a vacuum leak as well.

[junorico24]

Engine mount? Mine is kinda vibrating too.

[jRoss]

My engine shakes too, can't really figure out why. The only thing I have installed under the hood is an MI pulley which I have since reinstalled. I fear the worst, maybe I tightened the belt too tight and it bent the crankshaft or something. Idk what the heck to do :/ but I've tried everything I know to fix it and it continues to shake but runs fine for now...

[33OH]

If it doesn't get better quickly on its own, then clean the throttle body. There is a TSB about rough idle after disconnect where the solution is to clean the carbon deposits from the throttle body.

Did this, no avail. Any other thoughts? :frown:

[CTScott]

Did this, no avail. Any other thoughts? :frown:

Hmm if that did not help, it could be any of the above (MAF, coil pack going, etc. or it could be a fuel issue (dirty injectors, plugged filter).

[33OH]

Wouldn't you think it would throw a code for any of those? Or not necessarily?

I'd hate to just start throwing parts at it, but sounds like that's what I need to do.

[CTScott]

Wouldn't you think it would throw a code for any of those? Or not necessarily?

I'd hate to just start throwing parts at it, but sounds like that's what I need to do.

If any of those items were bad it would throw a code. If a coil pack was going by not completely bad it would not. With the fuel system as well, it would not throw a code until it got bad enough to start misfiring.

Before replacing parts I would do some additional cleaning and diagnostics, like doing a proper cleaning of the injectors, checking fuel pressure, etc.

[bail_w]

my engine was shaking after i disconnected the battery.

Edit: nvm, it still shakes after a while of idle.

[CrankyOldMan]

If it doesn't get better quickly on its own, then clean the throttle body. There is a TSB about rough idle after disconnect where the solution is to clean the carbon deposits from the throttle body.

This. I've had rough idle and stumbling acceleration for a few weeks now, with the occasional P0300/P0301/302/303/304 and the odd P0171. Finally got tired of it stalling at intersections and pulled the TB off. Not unreasonably filthy overall, but enough had built up around the rim to prevent it from getting the right amount of air at idle, as well as some sticking when opening/closing. I disconnected everything but the coolant lines because the TB cleaner specifically said NOT to use it on forced induction systems. A few squirts of cleaner and a minute with a shop rag cleaned it right up. Idles just fine now and responds much better to pedal inputs.

[Tedtalker]

Thanks Scott, I'll check the throttle body out. I remember it had some salt deposits on it anyway, so it's a good place to start. MAF was pretty damn clean, just had it out, so I'll check the TB first.

My MAF looked clean as well but after spraying with MAF cleaner there was noticeable smoothness and more power felt. Those little silver wires are very sensitive it seems. What can't be seen with the naked eye, but is obviously there is amazing to me.