trd_4runnin11

So my 4Runner hasn't been running too smoothly lately and I'm trying to figure out exactly what is wrong. I have been really strapped for cash lately so it has, unfortunately, been getting mechanically neglected somewhat. I have done as much as I can afford to do so far.

Problem 1: Rough idle. When in park or neutral it idles fine, when in drive it vibrates crazily. This seems to be attributed to slight drop in RPM when in drive as opposed to neutral/park.

- I have cleaned the TB, IAC, K&N air filter, and MAF sensor. Seems to help for a bit but then comes back. No codes.

Problem 2: (Maybe in conjunction with problem 1) Vibration while driving. Slightly noticeable at lower speeds but mainly very noticeable between 60mph and 70mph (seems to die down after 70). Goes away pretty much immediately when I let off the gas, or put in neutral. U-joints? Driveshaft?

-Tires have been rotated and balanced and are in fairly good shape. See my signature for suspension mods. May have nothing to do with this, but the steering rack is on its way out . I'm just filling with PS fluid and hoping I make it til tax return time to buy a new one.

Bigblock

Plugs -wires?
Bigblock

racermp

maybe engine/tranny mounts. usually u're putting strain on mounts when u put in gear (putting load).

trd_4runnin11

Plugs are relatively new. Id say within last 15,000 miles. I've thought about both wires and motor mounts but haven't looked that far into it yet. Any ideas on how to diagnose a motor mount?

Just Learning

on the motor mount have someone rev the engine slightly , while you look at the engine movement , if they are bad you will see it, try to get a visual on the mount are they oil coated??, to me for what little i know , it sounds like a u-joint

trd_4runnin11

I will do that with a friend. I know that when sitting still, I can rev the engine up and not really feel anything at all. I will check some things out and report back tomorrow. Thanks for the tips.

nah2323

Rough running:

Check the plugs & wires. doubtful on wires as there are only 3 and they are extremely well secured.

When in drive, car vibrates would point me to a M/T mount. lucky for you, you can pretty much see the entire underside from a kneeling position with your big lift..

60-70 shimmy. 1 of 2 things.

1.) check them lugnuts. I see you run spacers and probably do a bit of wheel changing. Look at your LN's for a mashed acorn out of round or something. torque those babies down to 83lbs.

2.) Tie rod ends / steering rack. Hopefully tie rod ends, as they typically lead to a vibration. If its them, I'm sure they've been on the way out for some time, and considering you run some beefy tires, you just didn't notice the vibration.

Greedy

Did you ever get to the bottom of this? I am having the same issue with a slight vibration and lower idle when in Drive and stopped.

Thanks.