Rough idle when in drive at a stop

DIRTY THROTTLE PLATE

when was the last time you pulled of your entire intake and scrubbed everything out?

 

Is this a product that goes into the fuel tank?

 

Not sure if this was for me or OP but I did a throttle body cleaning about a month ago. Was super dirty.

 

To Greenbean 10, A few months after posting this, I went to a few auto garages, the first wanted to do a 3 step cleaning without even checking things out, ( if I remember correctly - involved three different solvents which target the intake throttle body and fuel injectors) which I declined. I then took it to a garage that was highly recommended and left it there for them to look at. Since it has been a few years, the best I can remember is: there was no error codes, the Idle was off, so he reset the idle, also he said the motor mounts were worn, but not enoungh to need replaced. Did the idle reset work - maybe very very little. SO basically, I have learned to live with it.

 

Keeping the gas level above half full and using 89 seems to help, I cleaned the throttle body and it didn’t help. I’ll drive it around today again and see if it starts low idling again.

 

AFAIK there is no fix for the low idle (on an otherwise healthy vehicle with no codes or other problems).

My 2016 2tr-fe 2.7L started doing it one day out of the blue at around 85k miles. Have brought it to 5 different reputable shops and all of them had no idea what the cause is.

It's really annoying tho cause it used to idle in D and R up closer to 700-850 ish. Now it idles at a hair over 500. TB cleaning, new plugs, MAF cleaning etc did nothing to solve it.

 

Replace spark plug tubes gaskets.

 

I still haven't gotten to this. Vibration and all, it's still chugging along, taking my mother to and fro. Just slapped on some new TYC headlight assemblies to the tune of ~$65 a piece, and they sure do make the rest of the truck look like ass. Mom's been in three accidents now, and the former assemblies were being held in place by hockey stick tape (look into it -- it does what duct tape used to do)

I've hardly had a minute with the truck besides the above. I scoured it for vacuum leaks and didn't hear a peep. I'm certain that whatever's wrong, it's part of the journey to servicing the head gasket..

Wait. Mr. Steve, you think the spark plug tube seals could be the offender? Wouldn't that just be an oil leak? (a genuine ask)

 

Change them and find out. Good luck!

 

With the amount of 2.7i4 and 4.0 v6 Tacomas of various generations showing the low idle symptom, I highly doubt it's head gasket related cause that would be an issue that people could figure out rather easily

 

No. They’d cause a misfire. But not a rough idle. And even then, they’d have to be leaking pretty bad.

It’s probably the Throttle Body, MAF, or possibly Torque Converter drag (if it’s an Automatic with really high mileage).

Clean the MAF and Throttle Body.
If that doesn’t fix it. I’d just live with it until it stalls or throws a code.

 

Oh, buy new oe coils, too. Just do it. Cruise, cruise, cruisin’ along.

 

You're throwing a crap-ton of money at a nonexistent problem

 

A bunch of fair and well reasoned responses!
I'd forgotten that I already addressed the spark plug tube seals when I did the timing chain ~
Cat converters were already replaced with Walker. Throttle body assembly with TPS was already swapped for one from an ebay junkyard. That scrap TB is a little snappier, but the idle remains unsavory.

The truck's been running all the while with the fault. I don't think there's any harm in my throwing my own labor and occasional cash at trying to solve unpleasant idle vibration. Bonus: The truck runs better than ever and I've got no worries about it *except* for the continuing, persistent vibration.

Ooo, I also addressed secondary air injection

 

Fair enough, it's your money, go ahead..

But like I mentioned before, older toyotas are notorious for idling super low. The older Corollas do it, my old 1987 Supra idled at like 550 rpms when it was warmed up.

You need to manage your expectations a bit. Some vehicles are built more towards passenger comfort like higher-end sedans ( think Lexus, Mercedes, etc) they put more effort into insulating the cabin from what's going on under the hood. More sound dampening, better engine mount designs, a/c compressors that are variable displacement and don't click on/off changing the idle (like chevy). All these things keep the engine shakes and vibrations farther away from the cabin and the occupants.

Your 2wd truck is not one of these vehicles. It is built with utility and economy in mind. It hasn't stalled on you or broken down, there are no codes and it starts and runs every time you ask it too.

Are you seriously considering tearing apart the headgasket over this?

 

Not only am I considering it -- I'm totally all about it. Wouldn't be the first time!
I do understand that the engine mounting design isn't all that isolating: It's the thing's just sitting on solid epdm or whatever rubber, right on the chassis/subframe. But man, I'm telling yuh.. It's got a roughness to it when stopped in drive. The occasional hiccup, with no registered misfires. I really expected a timing issue, but no dice.
Could be valve lifters. I can't imagine how the head gasket itself would be at fault. But I've been through most all else. If I don't find the fault during the head gasket procedure I'll prolly let it be.

 

Its really annoying tbh...just enough of a vibration to notice it, but not enough to shake anything.

 

https://www.tacomaworld.com/threads/rmps-drop-when-shift-from-park-to-drive-reverse.819607/page-2

its a frequent complaint around here and no-one has yet found a cure

 

I'm surprised nobody has mentioned having the fuel injectors cleaned. From what I've read you are much better off cleaning or having the original injectors professionally cleaned over buying and installing cheapo aftermarket injectors. I would try that before pulling the head off.

 

I sure hope not.

There’s a better chance it will be worse by doing that. Wow

My man. If it’s not broke, don’t fix it.
Seriously, take that advice from one that’s been there, done that, made it worse.