[jwhiteney]

Hi,

I have a very noticeable vibration at idle. It only happens when the headlights are not on and the car has been warmed up a bit. When sitting at a red light the RPM will drop to between 595-605 (according to my OBD2 scanner) for 10 seconds or so, then RPM will jump up to around 700 and everything will be completely smooth but again after about 10 seconds it will drop back down to 600ish and vibration will start again.

For the life of me I can't remember when this started, it could have been since I bought it but I can't say for sure. Since I bought it I have had a remote starter installed professionally but not by a dealer.

Questions.
1. Would a remote starter being installed have cause this?
2. Is this behavior normal for the 18-20 Sienna?
3. Is there any way to increase idle speed?
4. Anything I can try?

Thanks for any suggestions

 

[hangman]

This is not normal. Does it happen with the AC off? Maybe the AC clutch bearing may be going bad and the AC clutch is dragging down the engine. Try turning the AC of and see if it still does it.

 

[fibber2]

Agree, it doesn't sound right, and unfortunately idle adjustment screws went the way of the dodo long ago. Still under warranty?

 

[jwhiteney]

This is not normal. Does it happen with the AC off? Maybe the AC clutch bearing may be going bad and the AC clutch is dragging down the engine. Try turning the AC of and see if it still does it.

hi, this happens with AC on or off. However it doesn’t happen when I have the AC on high.

Agree, it doesn't sound right, and unfortunately idle adjustment screws went the way of the dodo long ago. Still under warranty?

yes it is under warranty. I didn’t know if they would give me a hard time though because I had a remote starter installed. Would they say that is the reason for the problem?

 

[fibber2]

Sure, dealers will sometimes say anything to deflect from having to deal with a problem. But, they'd have to prove it was so. Unless your device placed some undue electrical load on the system at idle such that it produced some crazy load on the alternator and sunk system voltage, I don't see how it would be the cause. Have you tried taking a battery voltage measurement?

You could always start with the installer, and see if they have any ideas just to eliminate that possibility.

 

[edmoreau]

I’ve had the same behavior since Day 1 on my 2018 LE. I would notice it if I was stuck at a light for a long time, but not always. Never did pinpoint the magic combination. The vibration is not as bad as it used to be for whatever reason. It still alternates like that, but must not get as low as it used to because the vibration isn’t crazy. Never mentioned it to the dealer (have only been back for recalls).

 

[jiantao]

I have read similar complaints about the 2015 Honda CR-V. I haven't looked into it that deep since I don't own one. But, in the interest of saving fuel, engineers programmed the idle speed to be low when not under load. The problem is, the programmed it a bit too low and it shakes the car. IIRC, some CR-V owners resorted to just keeping the headlights on all the time (or keeping the rear defrost on) to increase the load on the engine/alternator and keep the RPMs a little bit higher at idle. If your car is under warranty, definitely take it back to the dealer and inquire about what solutions they may have. They might have some sort of software update or something similar.

 

[MichaelRS]

Your car is kind of young for that type of problem due to wear (although you didn't mention where you are in the country and what type of environment your car is exposed to) but assuming you're using the right grade and good quality of gasoline:

Dirty throttle body?
Dirty mass air flow sensor?
Dirty air filter?
Dirty spark plugs because some oil is slipping by on to them?
Malfunctioning idle air control valve?

Beyond any of that I got nothing.

 

[jwhiteney]

This is quite late... but I took the vehicle in shortly after I made this post and as expected they said everything feels normal. After I picked it up and got home I did notice on the service paper it said no vibration felt while idling in N or P... but no mention of D which is when it happens. When I dropped it off I explained it was happening in drive as I feel it while at a stop light. While I do understand this is a vehicle and there will be some vibrations i find it hard to believe this amount could be considered normal. Below is a video of what I am seeing. When the RPMs are at 700ish everything is very comfortable then not so much when it drops to 600.

https://youtu.be/w7ZWZLuzMZg

 

[saidiadude2]

Is the front defroster (and fan) on? It kicks on the AC when needed which can cause a drop in RPM. If AC is not on, and the radiator fans come on (hot engine), same thing happens to RPM.

 

[lou2005]

my 2004 sienna is having same issue. I need to turn on Headlight to avoid this vibration. I have replaced pcv, intake manifold gaskets, all spark plugs and still having this issue.

 

[slothman]

my 2004 sienna is having same issue. I need to turn on Headlight to avoid this vibration. I have replaced pcv, intake manifold gaskets, all spark plugs and still having this issue.

checked the motor mounts and trans mounts?

are you having erratic idle?