Vibration, shake when in gear at idle....

MY05 Outback XT 2.5t LTD wagon/automatic , October ’04 production – original owner. 74k easy hwy miles.. (downhill all the way…)

 

Maybe you guys can assist: Here’s the symptom: With the engine running and transmission in Drive, foot on the brake,,, say when stopped at a traffic light, a vibration & significant shake will start to occur, the idle RPM has dropped to 600-700 RPM; in the moment shifting to neutral will stop the vibration & shake symptom at once with RPM raising to a normal 900-950 say.

 

This vibration symptom had started a good 10k miles ago prompting a transmission mount replacement. The symptom was reduced however far from gone…. Torqueing the engine up with the brakes applied and the engine looks to be solid in place and not much movement if any. I’m thinking the automatic gearboxes torque converter is taking a dump? Does this fail all at once or slowly over time like my circumstance… How can a torque be checked? Or do I simply change out the muffler bearing….

 

Have a great day gents – gotta zoom. Anyone know of a responsible shop/Tech in the Alpharetta, GA 30004 area. I have a local shop called Scotts Auto Center in Cumming which seems to be OK….

a simple vaccum leak, like a hose popped off, under the hood can cause stumbly idle.... remove your TMIC and inspect the blue T fitting under it. follow all lines and hoses to ensure they reach and are attached to something. the torque converter is certainly not a common problem with the 5eat, they are rather robust. check your motor mounts, just get under the car and look at them, they are known to degrade over time....

bmx045 - thanks for the in put.

 

The idle is fine, only when in neutral though.

When the driveline is in "Drive" with a stopped vehicle (brakes applied) the car will shake, vibrate, etc. with the RPM dropping to 600/700RPM. At the very moment the vibration/shake is happening,,, simply by putting the transmission into Neutral cures all ills. ??? In Drive... vibration/shake,,,, in Neutral all is good.

As for the motor mounts??? what does a defective motor mount look like? My motor mounts appear solid, from what liitle can be viewed from below. When applying torque to the engine (e-brake & brakes applied, Trans in drive with foot on/off of throttle to rock the car, the engine show's little to no signs of torque induced movement.) Are the motor mounts bladder type, solid rubber type or others...???

Any specifics are helpful - Thnaks!

motor mounts have a rubber bushing in them. my legacy would idle rough and vibrate when i had low compression in 2 cylinders only when load is applied, like putting it in D

Yeah,,, thanks... just what I need is a couple of burnt valves....

 

The actual motor mounts in my OB look to be the solid type with a protective rubber skirt surround arrangement.

I'll check my life insurance policy first and only then while under the car observe the motor mounts under load.... "Honey,, rev the engine."

If I don't make it it was nice knowing ya'all ... you can thank me later for being the Bilstein BTS kit guinea pig....!

what's your oil consumption like?

My car was doing the exact same thing. Turned out to be #4 injector. Found it with Rom Raider watched misfire counts.

it could be a lot of things, unfortunately. misfires can cause shaking, vac leaks, dirty injectors, bad plugs, dirty maf sensor. all these maintenance items....

what's your oil consumption like?

 

Normal oil useage. Good question though. I own 911s and a sure sign of excessive valve guide wear is abnormal oil consuption.

My car was doing the exact same thing. Turned out to be #4 injector. Found it with Rom Raider watched misfire counts.

 

Thanks! ! ! .. Checked out RomRader ordering the appropreate cable. We'll see. (Actually I own a ODBII to USB port cable. )

A Great diagnostic tool to have.

tactrix is great, though you only need a vag-com cable which is $15, but the tactrix is faster and has less driver-related hassles. i also log frequently

I've used the VCSD (Vag com) for the VW cars in the house...

 

I'm getting a little stuck on the download .... maybe the Windows 7 is the culpurit. I'll look after it all after dinner.

The vag com works fine, like i said its the driver coordination...

Here’s the symptom: With the engine running and transmission in Drive, foot on the brake,,, say when stopped at a traffic light, a vibration & significant shake will start to occur, the idle RPM has dropped to 600-700 RPM; in the moment shifting to neutral will stop the vibration & shake symptom at once with RPM raising to a normal 900-950 say.

 

Have had the same issue for a while. When I asked about it at the dealership they said it may be from using an aftermarket half-shaft. IIRC it was the right front, the one that usually wears out and leaks grease around 70K miles. I bought one off of ebay, the same one lots of others on here have bought.

 

I replaced my Blitz air filter with a paper one (NAPA gold) a couple days ago and disconnected the battery to let the ECU reset. Seems less pronounced now. I'm stock and don't have a cable to check to check for misfires, etc.

Thanks, I'll disconnect the battery, giving your suggestion a go. Here's morsel of truth, when in Reverse the vibration & shake symptom is noticeably deminished from when in Drive.

Go figure. What changes when the drive train is in Reverse? We'll the half shaft's have an opposite rotation.... Go figure.

the half shaft doesn't move when you're standing still in D or R. I highly doubt that is the culprit. maybe it is the tranny? very hard to tell, you just need to use your judgement, we can't really help you seeing as vibrations can come from so many different places

maybe doing an ATF drain/refill twice to refresh the fluid may change things? again, hard to tell as it could be engine or tranny. atleast we know it isn't driveline related since you're not moving. the only other vibrations or lumpiness i can think of are misfires or large vac leak(hose blew off, not uncommon at all). once you get the cable to work, google "learning view download romraider" it's a simply exe program that takes a snap shot of learned ecu parameters and fuel trims (easy to tell if there's a vac leak). however if you d/c the battery it resets the ecu thus the LV snapshot won't show anything until you do some half hour of mixed driving with idle.

however if you d/c the battery it resets the ecu thus the LV snapshot won't show anything until you do some half hour of mixed driving with idle.

 

Very good piont. Two idiots One thought as we say in Germany. I'll hold off on the battery disconnect scheme until after Rom Rader does its thing.

 

Cheers,,

the half shaft doesn't move when you're standing still in D or R.

 

While no actual movement in D or R when in a stopped condition, the half shaft (axle) is attempting to move in opposite rotations;That's me piont.

then you'd hear a clunk when torsion is applied, switching between D N and R

The local Subaru dealership Tech observed the Outback XT today with all its vibration & shake when in Drive, stopped with the brakes applied. He suspects the driveshaft mid-piont (or center) bearing. Downloading the ECUs history didn't reveal any significant fuel or ignition issues. The motor mounts are fine in the Tech estimation, but will have a closer look later.

 

The next step is to get the car in the air and phyically inspect the driveshaft at the center ( mid-piont) carrier. Looks like we're on a drivetrain hunt.....

the half shaft doesn't move when you're standing still in D or R. I highly doubt that is the culprit. maybe it is the tranny? very hard to tell, you just need to use your judgement, we can't really help you seeing as vibrations can come from so many different places

 

Tons of posts on this at subaruoutback.org about aftermarket half shafts causing a similar problem....

you and your damn outbacks....

then you'd hear a clunk when torsion is applied, switching between D N and R

 

Moving through the positions D N and R do not produce any noticeable noise or clunk. Worn U-joints on the other hand have a signature noise that many of us have known.. There's none of that signature U-joint noise in the symptom.

I'll drop the exhaust/Cat portion today making room so as to grab the driveshaft at the midpoint bearing. If there is appreciable play at the driveshaft’s midpoint bearing I’ll know. Subaru sells only a complete front to back driveshaft assembly – there’s no bearing replacement available through Subaru USA. Go figure….

but i dont see why that mid-bearing vibration wouldn't be noticable when driving around, and on the highway....