2003 Outback vibration in idle - axle/timing belt?

[dhewitt]

Yes, I've read the million or so threads here about the idle vibration , but I think there may be some more interesting things in this case. (If not, I apologize in advance.)

 

I had our '03 Outback 4 cyl. in for a timing belt change (drive belts, water pump, and thermostat too) at 95,000 before a long road trip. It's otherwise in great shape and we follow the prevent. maintenance religiously.

 

First, a question: on this car there are 2 marks on the tach between 0-1, but three elsewhere. Is the first mark, which is thicker like the middle marks between the other thousand marks, for 500 rpm? And thus the second for 750? It's important here because I want to know where the standard idle (around 650) would fall on the marks between 0-1?

 

Two issues related to the work:

 

(1) While doing the job the mechanic checked on a smell we had noticed and found that the CV boot on the passenger front axle was torn and grease had leaked out - causing the smell. He replaced the axle with a N*PA one, but immediately called and said that it didn't seem right, so ordered a new one. That one went it, we drove 1,000 miles on a long trip with fine engine performance, and about midway noticed a clicking sound up front (freaking out my wife). We just had it in and he said it was another poor axle, so he replaced again (I know he's replacing them, he shows me, and I'd trust him with my dog). Does anyone have prior experience with these axles? The obvious response is "don't use N*PA axles", but he's confident it was just a bad batch. And, so far, this new one seems fine.

 

(2) After getting the timing belt changed, the car had a decidedly low idle only when stopped (less than a few MPH) and in gear (say, about that first mark, maybe 500 rpm) and it shuddered a bit. The shudder was noticeable mostly in the steering wheel and made an obvious noise, but not terrible; perhaps 2-3 times the normal shudder (which has always been more than on say, a little coupe). They adjusted the Idle Stop up a bit and the idle is now around that second mark (750?), but the shudder is the same (or maybe a touch worse). The shudder is no worse when it's cold, but can be sporadic, though its pretty consistent.

 

After doing some research, I'm convinced that the idle stop should not have been messed with (I hope it's easy to reset it to factory), and that reman'ed axles stink sometimes (though 2 in a row seems a bummer coincidence for me).

 

My mechanic is genuinely interested in fixing this and we're confused. His current working hypothesis is the engine mounts, which he says can offer poor buffer for these H4 engines. On this list I've also seen the reman'ed axles blamed and, unfortunately for me, that's confounding here. Someone else mentioned that the timing belt could be off a tooth - but wouldn't that cause some performance loss? (We got the same ol' MPG on that long road trip.) I imagine this could be checked with a vacuum guage.

 

Opinions, suggestions - Please!?

 

My mechanic even put the car on the lift to watch the engine when it was doing this (so presumably someone was in it on the lift - uh, OK), and he could stop it by "putting a bar under the engine". This was a short spur of the moment description, so I wouldn't read too much into it, but it he can stop it that way, does that lend credibility to the mount solution?

[porcupine73]

Hello and welcome.

 

Vibration can be caused by a number of things including as you mentioned motor mounts. The aftermarket axle/vibration stopped in drive thing on the autos seems to be a bit controversial. I would get that NA*A axle out of there and go with a Subaru OEM reman from a Subaru dealer (find a good Subaru dealer who sells parts online to save over a local dealer), or check out MWE axles. Ok maybe it is just coincidence but there have been lots of threads with the strange vibration when stopped in drive after replacing an axle.

 

Likely the battery was disconnected during the work; it takes the vehicle some time to relearn all its operating parameters after that. Otherwise try cleaning the idle air control valve and/or giving her a good seafoam treatment.

 

Right on, I don't know what they mean by 'adjusted idle stop' since there is no such thing. The idle is electronically controlled via the idle air control valve. What they may have done is turned some screw that is now holding the throttle open slightly at idle. This definitely should not have been done. Or if they messed with some adjustment on the iacv I think Subaru says replace it.

[dhewitt]

Vibration can be caused by a number of things including as you mentioned motor mounts. The aftermarket axle/vibration stopped in drive thing on the autos seems to be a bit controversial. I would get that NA*A axle out of there and go with a Subaru OEM reman from a Subaru dealer (find a good Subaru dealer who sells parts online to save over a local dealer), or check out MWE axles. Ok maybe it is just coincidence but there have been lots of threads with the strange vibration when stopped in drive after replacing an axle.

 

Thanks a lot for the help!

 

I'm gonna chat with my mechanic to be sure he's confident that the timing belt installation is not a concern, then I think I'll suggest we start with the axle and see if that works. Being on the 3rd N*PA axle scares me a bit anyway for long-term. Your suggestion prompts the obvious query - OEM from Subaru or MWE? Someone else mentioned a brand sold at Advance that was good (didnt say which) or EMPI (don't know how to get those).

 

My mechanic cleaned the IACV the first time we noticed it - that was his first guess. It seemed to fix it for a half day or so, but then it came back. Not sure if that helps in diagnosis.

 

I noticed someone else found a vacuum leak and a new PCV valve fixed it. That's cheap and might be an easy second step, along with a new IACV. I'm tending to think that the motor mounts should be a last option.

 

Likely the battery was disconnected during the work; it takes the vehicle some time to relearn all its operating parameters after that. Otherwise try cleaning the idle air control valve and/or giving her a good seafoam treatment.

 

Right on, I don't know what they mean by 'adjusted idle stop' since there is no such thing. The idle is electronically controlled via the idle air control valve. What they may have done is turned some screw that is now holding the throttle open slightly at idle. This definitely should not have been done. Or if they messed with some adjustment on the iacv I think Subaru says replace it.

 

As a last bit, you must know what the 2 tach. marks between 0 and 1 indicate in terms of RPMs, no? Is that 500 and 750? And why couldn't they just use the three-mark intervals as in the other areas of the tach, to save me a headache?

[WAWalker]

Yes the tach marks are 500 and 750. No need to have the tach read below 500.

 

I used NAPA remaned axles for a long time. ARI went out of business, so I started buying the NAPA NEW MAX axles. Got a batch of bad ones, tried the remaned axles, different box same new axles same problem. Haven't used them since.

 

If the engine idle was lower after the timing belt replacement, I would look there first.

 

No the throttle stop should NOT have been messed with.

 

There is no adjustment that can be done to the IAC on an '03 so that shouldn't be an issue. So far they have a fairly low failure rate as far as I know, so I wouldn't be in a hurry to replace that.

 

If the shudder is worse since the time belt replacement/idle drop. First thing first. Check cam timing.

[idosubaru]

get MWE axles. avoid aftermarket axles like the plague for subaru's. i don't work on other cars enough to know about them, but i will never put anything but MWE or Subaru axles in Subaru's. as new as your car is a used axle from the junk yard is a better bet than anything you can buy in an autoparts store because it should be an original Subaru axle. MWE is a member here and is great to work with.

 

if it idled fine, then didn't after the belt change then things need to be looked at that were messed with. the engine mounts won't fix this. ask him if he did anything with the spark plug wires or intake during this job. if so you need to make sure all the wires are seated perfectly and there are no vaccuum leaks. the EJ engines are very sensitive to ignition wires - they should be Subaru only (Magnecor is the only suitable alternative on EJ engines, which is yours). so if he also replaced the ignition wires at this time, and they were not Subaru, i would not be surprised if that was the problem. i've seen brand new wires from the store cause very bad problems.

 

the cam being off a tooth should be very noticeable, so i doubt it. but the timing components are worth checking into if need be. was this a Subaru or after market timing belt? got the part number?

[dhewitt]

get MWE axles. avoid aftermarket axles like the plague for subaru's. i don't work on other cars enough to know about them, but i will never put anything but MWE or Subaru axles in Subaru's. as new as your car is a used axle from the junk yard is a better bet than anything you can buy in an autoparts store because it should be an original Subaru axle. MWE is a member here and is great to work with.

 

if it idled fine, then didn't after the belt change then things need to be looked at that were messed with. the engine mounts won't fix this. ask him if he did anything with the spark plug wires or intake during this job. if so you need to make sure all the wires are seated perfectly and there are no vaccuum leaks. the EJ engines are very sensitive to ignition wires - they should be Subaru only (Magnecor is the only suitable alternative on EJ engines, which is yours). so if he also replaced the ignition wires at this time, and they were not Subaru, i would not be surprised if that was the problem. i've seen brand new wires from the store cause very bad problems.

 

the cam being off a tooth should be very noticeable, so i doubt it. but the timing components are worth checking into if need be. was this a Subaru or after market timing belt? got the part number?

 

I'm pretty sure he said he had to get the belt from Subaru to be safe. I'll check and let you know.

[dhewitt]

Almost forgot... both of you mentioned cam timing, but would that only happen when it's in gear and stopped? Wouldn't that be noticeable at other times? Ditto on the wires? I don't know, just thinking out loud.

 

get MWE axles. avoid aftermarket axles like the plague for subaru's. i don't work on other cars enough to know about them, but i will never put anything but MWE or Subaru axles in Subaru's. as new as your car is a used axle from the junk yard is a better bet than anything you can buy in an autoparts store because it should be an original Subaru axle. MWE is a member here and is great to work with.

 

if it idled fine, then didn't after the belt change then things need to be looked at that were messed with. the engine mounts won't fix this. ask him if he did anything with the spark plug wires or intake during this job. if so you need to make sure all the wires are seated perfectly and there are no vaccuum leaks. the EJ engines are very sensitive to ignition wires - they should be Subaru only (Magnecor is the only suitable alternative on EJ engines, which is yours). so if he also replaced the ignition wires at this time, and they were not Subaru, i would not be surprised if that was the problem. i've seen brand new wires from the store cause very bad problems.

 

the cam being off a tooth should be very noticeable, so i doubt it. but the timing components are worth checking into if need be. was this a Subaru or after market timing belt? got the part number?

[idosubaru]

both of you mentioned cam timing,.

i didn't:

the cam being off a tooth should be very noticeable, so i doubt it.

i mentioned that it's probably NOT cam timing.

 

i would not be surprised to see wires on the other hand cause an issue only felt at idle.

what brand are the ignition wires and are there (or have there been) any check engine lights?

[dhewitt]

i didn't. i mentioned that it's probably NOT cam timing.

 

i would not be surprised to see wires on the other hand cause an issue only felt at idle.

 

what brand are the ignition wires and are there (or have there been) any check engine lights?

 

Sorry for the confusion, and thanks for the continued help.

 

The check engine light has never come on in this car for us. My mechanic never touched the ignition wires or intake - they're OME - and he had checked vacuum leaks and found none. He did use a NAPA timing belt, so that could be a second thing to check. Didn't get the part number.

 

I spoke with my mechanic today and he right off said he wasn't convinced anymore that it was mounts, and wanted to dig a little (this guy's good). He had checked with some folks that agreed it probably wasn't mounts.

 

We're gonna start with a new axle from Marshall at MWE and see where that leads. It's still odd that an axle issues can generate these symptoms, but it seems to be a recurring problem.

 

My mechanic also mentioned that he had only adjusted the throttle stop a "few thousandths" because that's just not something you can do on these engines. In other words, he realized that fallacy and hadn't done something stupid (I'm liking him more and more).

[WAWalker]

If the idle is just perceived to be low, due to the increased vibration, then a quality axle may be all you need.

 

Definetly a good start. As you know my opinion on the Napa axles.

[dhewitt]

If the idle is just perceived to be low, due to the increased vibration, then a quality axle may be all you need.

 

Definetly a good start. As you know my opinion on the Napa axles.

 

My mechanic was surprised but intrigued when I told him about the axle issue. He hadn't heard of that. I ordered the axle and he's gonna do the job for free. If the new axle doesn't fix the problem, I'll be frustrated.

 

Incidentally, we're smelling the same smell that arose when the boot on the original axle was torn (why we took this in to begin with). I'm guessing it's another bad NAPA axle that's just taken a few weeks to go bad. I hope it lasts.

[dhewitt]

Just wrapping this up...

 

In the first reply to my query, porcupine said:

 

maybe it is just coincidence but there have been lots of threads with the strange vibration when stopped in drive after replacing an axle

 

It don't seem like a coincidence to me... we replaced the NAPA axle with a MWE axle yesterday and we're back to normal!

 

My mechanic said something to the effect of "What the heck? They looked the same, and I can't imagine what caused that." He asked for Marshall's contact info in case this comes up again... he was intrigued.

 

Thanks a million guys.

[screwbaru2]

Am I correct thinking that this wouldn't happen to a manual tranns? With the clutch disengaged there would be not torque on the axle.

[idosubaru]

Am I correct thinking that this wouldn't happen to a manual tranns? With the clutch disengaged there would be not torque on the axle.

no they'll still do it too...there are variables involved and the failure modes may be slightly different than what this poster experienced but usually they vibrate under load...while accelerating, a manual or auto will both do that.

[talkstoplanets]

Bringing this back from the dead...this was new to me so I had to let folks know about the axle issue.

 

There is truth to the replacement axles causing crappy idle, I just rectified it on my '07 Impreza. 

 

The original inner boot tore at about 130K and starting flinging grease onto the cat, I figured it out after investigating the smell.  It was a weekend and I needed a quick fix (commuter car), so the only axle that I could find on a Sunday was an aftermarket unit from Advance.  Outwardly it looked like a correct match in size and there were no problems installing it, but as soon as it was put back together the rough idle started.  I've done work on my own cars for 20+ years and have never seen anything like this, I chalked it up to coincidence since there was no logical reason that the axle would do this.  I chased all kinds of things and drove myself nuts trying to figure it out...PCV, spark plugs, vacuum, EGR, stuck valves etc. but nothing helped.

 

After searching through multiple message boards I found a small mention of it but no one seemed to follow up on it as a legitimate thing.  Since I had run out of options I gave it a shot and replaced the Advance unit with a Subaru used axle from a dismantler.  Problem solved!  Idle is back to normal and all is well again.

 

The Advance axle was fine at cruising/driving speed with no vibration, but apparently the tolerances were not as exact as the OEM piece.  The only thing that I can think is that the axles act as additional dampers/mounts on our longitudinally-mounted engines (the main motor mounts are relatively small in my opinion), and any play in the axles/CV joints magnifies engine vibration.  At any rate, if anyone comes across this particular problem it's well worth repairing your axles with OEM units.  While they are quite pricey new from Subaru, they can be found used online for much less.  I found mine for $85 delivered from a 50K-mile car so they are out there.