Vibration at low rpm/ Idle

My tacoma has the 3.4 and I have noticed when the truck is warmed up I can feel a little rumble/vibration throughout the whole truck while at idle. It is worse while in gear and goes away with slightly touching the gas. The truck also seems to idle kinda low (halfway between 1k and 0) when at operating temp and in drive. In park it idles a little higher and the vibe is less noticeable. I have replaced spark plugs, spark plug wires, cleaned maf and also put a can of sea foam in the gas tank. Anyone now a fix for this problem? Pretty much what this thread is about Anyone know whats the problem? Thank you

 

Idk could be a number of things. Motor mounts maybe? I had a new exhaust system installed and since I get a little vibes while idling as I think its vibrating a little bit and making the whole truck shake a lil. I haven't tried to fix it yet. But might be a thing to look at. Maybe put your ebrake on and get out and check that just because. Before you delve into motor related causes.

 

I think its engine related because the vibe is intermittent. If it was something like motor mounts or exhaust wouldn't the vibe be constant?

 

just like toendanger said. ive heard about vibes at low rpm commonly related to bad mounts in FWD vehicles since they have like 4 or 5 mounts. could be your situation too. check it out. mainly stress this because there shouldn't be anything vibrating enough to cause vibes to travel throughout your truck, outside of the motor. and any vibrations caused by the motor are supposed to be dampened by your motor mounts.

it's really only pointing to 1 issue, the mounts. good luck!

 

Usually yeah. But mine does vary a little. Idk I was just saying might be something to check. You can check your motor too the same way. Better if a buddy helps and you watch the motor as it shifts. You should be able to peek under the windshield with hood open and see the top of the motor and shift it in and out of gear if automatic, to see if motor has a lot of movement. Idk. That's what I was told to do but I've never messed with motor mounts so I may be wrong on the diagnostic method of that.

 

no, you're right. the torque on the engine revving will lift it off of a mounting point in some cases. or you could put a jack underneath and lift the engine while looking at the mounts to see if there's any free movement at the motor mounts after the body settles at it's own weight and without the weight of a motor.

essentially, the front end should lift up along with the motor if the mounts are good. but if the mounts are bad (separated) the engine will continue lifting at the mount points without "lifting" the body/frame.

 

Could be a vacuum leak somewhere. Check all of the lines downstream of the throttle.

 

I've been dealing with a low and high idle for a few years. Only seems to affect idle. once driving there is no issue. I sometimes get down to 250 rpm and sometimes up to 1200 rpm so it's noticeable.

your 500 rpm isn't bad and since you have a 2000 try cleaning your IAC under the throttle body (get new gaskets).

 

500 rpm is definitely too low, it should be around 650, when warmed up. A small vacuum leak will definitely cause the idle to be rough and too low, and not affect cruising.

 

I just cleaned the MAF sensor on my 2011 because it got rough at idle and a buzz vibration at load. seemed to do the trick for me.

I started to notice a buzzing vibration in the floorboard and peddles. I also noticed that my MPG dropped about 2.5. I wasn't sure whether it was winter fuel or something with the engine... around here my MPG always drops about 1 or 2 in the winter but I never notice a rougher engine due to the fuel changes. I took a shot at it being a MAF sensor starting to give bad readings due to crud. I went to my local auto shop and bought CRC MAF cleaner. it was about $8. It took 5 minutes to get the MAF out on a 4.0L and cleaning was nothing more than straying the sensor to clean it... mine was not shinny when I took it out.. more like a light carbon color... after cleaning it looked like new wires. I cleaned the exposed wires and some wires inside the sensor. I never touched them just sprayed and let dry. I also reset the computer by disconnecting the battery for 20 minutes. between the two it seems to have done something positive. It feels smoother. time will tell if my MPG goes back up or not. all said and done I am only out $8 and 20 minutes.

might be worth giving this a try.

Carl

 

I have already cleaned the maf about 2 months ago, mabey Ill try again

 

not a mechanic but had issues on my other car rough idle and came up to clean the trottle body (the flapper and inside) fixed it, then did the taco for good measure.

 

Yep, cleaned the throttle body and it fixed it.

 

I cleaned my throttle body and its still present.
Maybe vaccum leak?
It's a rotating predictable Rumble.
Not a lot of vibration but enough to make me notice
I was wondering if an exhaust leak could do it. I don't smell any exhaust fumes tho

 

Have you replaced spark plugs and wires recently?