Engine Vibration/Rumble After Mount Replacement

2002 Toyota Tacoma
2.4L
4 Cylinder
2WD

I purchased this truck roughly 2 years ago with 79,000 miles on it, single owner in Alabama (flat part of the state). It now has 137,000 miles on it.

Over the past several months there has been an increasing vibration in the engine. The roads I drive everyday are rough. The highways in Louisiana are shit and I work at a mine and have to drive roughly 4 miles of gravel/mud road everyday. I average 100 miles every day for my commute. I have recently replaced the fuel pump (shat the bed on me), rear shocks, front shocks (they were originals), and spark plugs. The vibrations continued to increase until the point were I decided to change the motor mounts and transmission mount.

The vibrations/rumble before the mount change were very noticeable in the steering wheel, front dash, hood. They were only noticeable when I am stopped (Park, Neutral, Drive). This was whether the engine was cold or warm.

After the mount change the car does not vibrate when I just start the truck up for the drive. As soon as the engine begins to warm up and I am stopped the engine will start to rumble/vibrate. I am now feeling the majority of the vibrations in the center console, seat underneath me, somewhat in the door. When I turn the A/C on the vibrations/rumble seems to smooth out. Again I can only feel the rumble/vibrations when I am stopped (Park, Neutral, Drive). My idle seems to fluctuate a little when idling. Every now and then it will jump up to 1100 and then back down to the 700-800 rpm idle. Also, I am hearing considerably more valve tapping than usual. It has been on my list to check the valve clearances but I have not had the time.

Any suggestions on where to start to chase the cause of this vibration down.

 

Center driveshaft bearing? Its located under where the center console is. Not saying its definitely the case, but if so there is a DIY here for it. Body mounts also might be the case.

 

Would a bad carrier bearing cause engine rumble and vibration at idle (foot on break) in (Park, Neutral, and Drive)? I would think that a bad carrier bearing would cause vibration upon acceleration. You can clearly see the engine rumbling heavily when stopped (only after warm).

 

No, if you feel this vibe at stand still (park/neutral) Your issues are else where, did you watch pulley/belt operation while running ? You said something about a mount ? was it motor mount or trans mount ? Check them all again.. Get some audio/video if you can, helps a lot...

 

All three mounts were replaced (right motor, left motor, transmission mount). I will try and take some video today after work. The pulleys/belts all seem to be fine.

 

Depends, is more audible or can you feel it below the console? It can certainly cause audible vibration when stopped or when creeping forward. If its also easily felt in the body, then it may be something else.

 

Kinda wondering how a carrier bearing is going to make noise or vibrate at a stand still, not turning...

 

Not the bearing itself, the mounting on the body possibly being loose. Ive seen it on other cars, not speaking form experience with a Tacoma.

 

I have the same problem with the same engine. Starting to get really annoying! Serious vibration at idle in gear while not moving. Seems to be caused by low rpm's. With the a/c on the engine rpm's are raised to compensate=no vibration. Hasn't been an issue this summer because the a/c is always on. When first started the rpm's are raised also=no vibration. I have been thinking about doing seafoam to see if that will help. It isn't the carrier, and it isn't the mounts for sure. I run a used car lot/repair shop so the last thing to get worked on is my daily driver truck unless it causes it to not run. lol. Would be nice to know what to go after to save time/laziness.

 

Have you scanned for codes ? Its a computer controlled engine .
Sounds engine related to me . If the vibe is fealt when you are at a standstill in park with the engine running , you have eliminated the drivetrain as being the problem . Throttle body cleaning ? Mass air flow cleaning ? Remove the serpentine belt and start the engine for a short test

 

Working with a Snap-on Verus wireless to check my codes. No codes, but I know the truck shouldn't idle at 550-600 rpms once it warms up. I've been working on transmissions since I was young (3rd generation transmission mechanic owning our own businesses), and that picture of your tranny pan magnets is funny. Was that the planetary gears that exploded? I love my taco, but I keep an old V8 explorer around for towing my boat and other stuff. Sorry I made fun of your pain.

 

Seafoamed my turd today. Made a HUGE difference! Only drove it home from work today. I'll see how it does tomorrow.

 

Found the problem. Engine idles around 600 RPM, but I guess the only way to fix it is by replacing the ECM.

Subject: Rough Idle correction for 1995-97 Tacoma with 2RZ-FE or 3RZ-FE engine

Source Toyota technical service bulletin EG006-00 (August 2000)

The operating logic of the replacement ECM has been revised to improve engine idle
smoothness. This is accomplished by raising the engine idle speed with the A/C off. The
change also narrows the engine speed transition between A/C off and on conditions.

 

yikes, talk to me about this
help me to diagnose gremlin rattle rumble vibration
its been going on a few months now

 

HFS how come nobody has pointed me to this thread yet ?!?!?


how the heck does this work with MT

most of this info is with AT


@1997tacomav6 ... have you run into this issue within this very old thread?


perhaps anybody else?
there has been no topic thread on this for 3years now

 

Nope, only vibration issues for me was a bad Cardan joint

 

and your mileage!
rubber engine mounts, these are a function of years some would say

 

you never hardly run your truck at 2.1k rpms in all gears do you?
i mean when you shift you are never going back to there and speeding up for next gear
i do and this is where i get my rattling most the time lately

 

@1997tacomav6 ... have you had any issues with this ECM?

 

Still on original motor mounts