I'm new to YotaTech. It's awesome. I just returned from a stint as a Peace Corps Volunteer and bought a 1995 Tacoma automatic 2.4L 2WD.

After the truck has warmed up I'll come to a stop at a red light or stop sign and it vibrates like crazy. The hood, steering wheel, rear-view mirror, and my teeth. If I put it in neutral it stops but starts again if I put it in Drive. As I pull away it stops and acceleration is great. I just did a full tune-up (plugs, wires, cap, rotor, air filter). It still vibrates.

What could be the problem?

Thanks a ton. And thanks to those who manage this site. Y'all rock.

 

torque converter going out maybe?

 

What causes a torque converter to go out?
-lack of fluid change?
-towing?
What can I do to find out if it is the torque converter?
Fixable?

 

Has anybody else had this issue with a Tacoma? I don't think it's the torque converter because acceleration is great and gear changes are normal. Thanks for the help.

 

motor mounts worn or boken? tranny mounts worn or broken?

im pretty sure you can rebuild a torque converter, but ive never seen any kits for toyota's...not saying they're not out there though.

if it was me i'd just go out and buy a new torque converter as rebuilding one takes alot of skill and patience, plus its time consuming.

but im not 100% sure, ill wait to see what the pro's have to say, but if the torque converter was going bad i think it would slip, jerk or shake real bad etc. throughout all the gears

 

I was also thinking the main tranny mount underneath in the middle. It's not uncommon for the rubber to crack/break there.

 

I would clean your throttle body, IACV, and MAF to start, especially if it has not been done. You will need to remove the throttle body to get to the IACV. You will need to buy a paper gasket for the TB. You can reuse the rubber gasket on the IACV. Seafoam Deep Creap is a good cleaner. The IACV is on the bottom of the throttle body. Slightly rough Idle is pretty common on 2.4/2.7L. It should Idle around 750.

 

If you give it just a little throttle, does it smooth right out? That's the same thing both of mine are doing. Shakes when warm and idling in gear (not in park or neutral). I've cleaned the MAF and throttle body, changed the plugs and plug wires, new air filter, cleaned IAC, tried replacing the TPS, flushed transmission, nada.

I think that the engine mounts or transmission mounts might be a good place to check next. Goodness knows that the crappy shocks on my trucks are rattling things around pretty bad.

 

Yeah, it does smooth right out when I give it just a little throttle. I think y'all might be right about tranny or engine mounts.

Mine still idles a little rough in PARK when it is warm but not as much as REVERSE or DRIVE.

I'm also going to look into checking vacuum lines for leaks. I think that could be the problem as well. I'll use the clever starting fluid trick. I'll also clean, all intake components too.

Thanks to all for this thread. I hope to get to the work this weekend. I'll update as events occur.

 

Simigeology was right.

I went to the parts store after work today for a PCV valve, carb cleaner, paper gasket material to make new TB gasket. I decided to be lazy because I have to drive south for a free camper top for my truck so I left the TB on and cleaned it with carb cleaner and lots of paper towels. Just kept spraying and wiping. There was some serious gunk in that throttle body. The paper towels finally started coming out brown instead of black. Replaced the PCV valve because it only costs $3. Checked all vacuum lines and connections and they were good. Put everything back together and tightened it all up. Voila! The crank took awhile with all that carb cleaner. It came to op temp and no vibration. Just the small vibrations that one expects from a 15 year old truck.

Thanks to all who contributed to this thread. It feels good to have the truck running at optimum. I just can't wait to check my fuel mileage now. It's got to be better.

Now it's getting a 20 year old camper top and hopefully will be carrying a canoe around this summer for me to go hiking/fishing.

Pendrag, good luck. Let us know if it's the mounts for you. Before tackling that check all the other easy stuff like EGR and PCV valve and associated hoses and vacuum lines. Make sure you clean the back side of the throttle body flap inside. That's where all the gunk was in mine. Check the dist cap and rotor button too.

 

So we all thought this thread was dead. Well no. The vibration/rough idle came back shortly. Yesterday and today I removed the throttle body and idle air control valve (IACV) and cleaned them thoroughly. Checked all vacuum lines and cleaned MAF. So the complete list of procedures to cure the vibration up to date are:

1. remove TB and IACV and clean them throroughly. Also tested IACV. It's good.
2. replaced belts, spark plugs, plug wires, dist. cap and rotor.
3. removed MAF and cleaned thoroughly.
4. disconnected top vacuum hose going into EGR and clamped it shut.

All of these did not fix the problem. It still vibrates while in D or R and at a stop only at operating temperature.

My next attempt will be Sea Foam down the PCV hose to clean of the valves.

Help! What else could it be? Tranny mount?

After this I think it's going to the Toyota Dealership up the road and I'll let them sort it out, albeit with my wallet getting thinner.

Any fresh ideas would be greatly appreciated.

Have a good weekend all.

 

what rpm is it vibrating at, my reasoning here is prety simple if im understanding it right. it goes away at the blip of the gas raising rpm, i think if its idling lower than spec with the drag from the torque convertor it would shake the motor a little trying to maintain the low idle speed, just a thought but what rpms are we talking about?

 

There is no tachometer on my truck.

It idles just fine before it reaches operating temp. You can actually watch it happen. As the temp needle moves to where the thermostat opens...BHAM, the vibration kicks in. Kind of makes me think vacuum leak of some kind but I did my best to eliminate this.

 

i would check the bimetal switching valve for the coolant vacuum switch. it is closed until operating temp and opens when at temp and allows vacuum through it. i believe it is connected with the charcol canister but could be mistaken

 

and a bad vacuum leak at idle would cause stumbling i think. you could do the propane or smoke trick to narrow it down

 

I just checked the VSV on the charcoal cannister and it is bad. I took it off and hooked up the battery with jumper wires. No air passes through with or without voltage. $148 at Toyota dealer. $35 online. Waiting a few days and I'll hook it up.

So I un-hooked the vacuum hose from the valve and it was drawing vacuum. I spliced that one on the one attached to the charcoal cannister so it was sucking the gas vapors from the cannister- bypassing the VSV. Idle smoothed out. Not all the way but much better than before. Plus I have the piece of mind that my emissions are in check. I know that's not a big deal for most but it's nice to know.

Blake, thanks a ton man. It is such a good feeling to track a problem down. Plus I know my TB and IACV are clean and the tune up is good too with plugs, wires, cap, and rotor.

Perhaps this is the end of this thread. I'll update when the VSV comes and I install it.

 

up&down,

did you replace the vsv? did that solve the issue? please update.

 

Not yet. I'm hoping the VSV comes in the mail today. Though I seem to be cursed when it comes to online ordering. It is a simple replacement in <10 minutes. I'll inform the thread as soon as it is installed and the engine reaches op temp.

My next step is to track down and stop a horrible squeak under my passenger side front. I've sprayed everything with silicone to try to stop it and thus pinpoint the squeak. It happens over bumps and when turning the wheel.

Any suggestions? Tie rod ends? Ball joints? Shocks? Sway bar links or bushings? Please don't say control arm bushings.

 

i had same problem with that vacuum switch on my vz, i just bypassed it and run vacuum to the canister all the time after all it is only cut off till the engine warms up and i have had no problems from it it least to now

 

I thought about bypassing the VSV too but was worried about fuel/air mix as the car is warming up. It might get too rich before the VSV opens up. Just a thought.