HELP!! idle problems and more..

**blest** · 05-17-2010 10:41 PM

Welp, im at a loss and i need loads of help.. any input is appreciated!! to start here is info on the car..

2002 wrx 88k miles (approx. 45k on engine clutch and tranny(5MT))

stage 2 clutch
APS BOV
injen CAI
blitz turbo back exhaust
MRT up pipe
MRT TMIC
cusco front and rear sway bars w/ endlinks
cusco front and rear strut bars
prodrive springs
cobb short shifter kit w/ bushings
ECUtek EM
blitz turbo timer
cobb 332mm front brake kit

think that about covers it for anything that could possibly have an effect on what im experiencing.. so heres my story.

Approx 1.5k miles ago started to notice a type of.. bumpiness coming from what i thought to be front passenger side. (this was confirmed by a friend of mine after riding with me and experiencing the problem). This only occured when turning, noticed mostly when the wheel was cranked all the way to one side or the other. I also tended to noticed it more after driving on the highway rather than when the car had been driven a very short distance. I didnt however notice it at speeds over approx 25. So i decided to check the basics.. wheel bearings, tie rods, cv axles. All looked good (and still do). Over the course of the next 1k miles i continued to notice it intermittently, but i wasnt driving often and couldnt figure it out so it was easy to put off. I should also note that when it does this there is no strange noise or anything, just the feeling of bumpiness from the passenger side. eventually took it to a couple mechanics, and they all said the same thing which was that they couldnt feel it. so i figured my subaru paranoia was acting up and disregarded it. I had to make a 300 mile trip a few days ago and i knew my fluids needed to be changed, so changed oil, oil filter, cleaned air filter, changed rear diff and trans fluid, replaced fuel filter. All fluids looked good when changed and were replaced with Royal Purple.

So i made my 300 mile trip without problems. After driving around town for a few days though things went WRONG. This evening started to notice the bumpiness alot, its extremely bad when turning now and is no longer inconsistent, its constant when turning and very noticable.
To top it off my idle is now acting up.. idle keeps dropping to approx 500 rpm, sputters a bit, then raises to 750, then just idles very inconsistently between the two. This just started happening about 10 miles ago. I should note that my plugs, wires, rotor and cap all have about 45k on them, so i figure its either a combo of those things or my IAC. Plugs, wires, rotor and cap will be replaced within the next few days. Fingers crossed its not my IAC, but if there are any other ideas as to what it could be PLEASE throw them out there.

The main one that is stumping me is the bumpiness coming from front passenger side when turning. Like i said, tie rods, wheel bearings, and cv axles are all good.. it makes no sound when it happens and it makes no difference whether the car is in gear or not, it is just as bad when turning in neutral. Any advice is greatly appreciated on either of these problems, thank you for the help sorry for the long read!

**blest** · 05-17-2010 10:50 PM

I should also add that i always run 92 octane fuel and my CEL is on.. i dont have o2 sensors though so this is always the case. Im going to go pull the codes in the morning to see if there is anything in addition to the o2 sensor that could be causing this.

**EvoEatr** · 05-18-2010 03:02 AM

Originally Posted by blest

Welp, im at a loss and i need loads of help.. any input is appreciated!! to start here is info on the car..

2002 wrx 88k miles (approx. 45k on engine clutch and tranny(5MT))

stage 2 clutch
APS BOV
injen CAI
blitz turbo back exhaust
MRT up pipe
MRT TMIC
cusco front and rear sway bars w/ endlinks
cusco front and rear strut bars
prodrive springs
cobb short shifter kit w/ bushings
ECUtek EM
blitz turbo timer
cobb 332mm front brake kit

think that about covers it for anything that could possibly have an effect on what im experiencing.. so heres my story.

Approx 1.5k miles ago started to notice a type of.. bumpiness coming from what i thought to be front passenger side. (this was confirmed by a friend of mine after riding with me and experiencing the problem). This only occured when turning, noticed mostly when the wheel was cranked all the way to one side or the other. I also tended to noticed it more after driving on the highway rather than when the car had been driven a very short distance. I didnt however notice it at speeds over approx 25. So i decided to check the basics.. wheel bearings, tie rods, cv axles. All looked good (and still do). Over the course of the next 1k miles i continued to notice it intermittently, but i wasnt driving often and couldnt figure it out so it was easy to put off. I should also note that when it does this there is no strange noise or anything, just the feeling of bumpiness from the passenger side. eventually took it to a couple mechanics, and they all said the same thing which was that they couldnt feel it. so i figured my subaru paranoia was acting up and disregarded it. I had to make a 300 mile trip a few days ago and i knew my fluids needed to be changed, so changed oil, oil filter, cleaned air filter, changed rear diff and trans fluid, replaced fuel filter. All fluids looked good when changed and were replaced with Royal Purple.

So i made my 300 mile trip without problems. After driving around town for a few days though things went WRONG. This evening started to notice the bumpiness alot, its extremely bad when turning now and is no longer inconsistent, its constant when turning and very noticable.
To top it off my idle is now acting up.. idle keeps dropping to approx 500 rpm, sputters a bit, then raises to 750, then just idles very inconsistently between the two. This just started happening about 10 miles ago. I should note that my plugs, wires, rotor and cap all have about 45k on them, so i figure its either a combo of those things or my IAC. Plugs, wires, rotor and cap will be replaced within the next few days. Fingers crossed its not my IAC, but if there are any other ideas as to what it could be PLEASE throw them out there.

The main one that is stumping me is the bumpiness coming from front passenger side when turning. Like i said, tie rods, wheel bearings, and cv axles are all good.. it makes no sound when it happens and it makes no difference whether the car is in gear or not, it is just as bad when turning in neutral. Any advice is greatly appreciated on either of these problems, thank you for the help sorry for the long read!

If you said you checked everything in the suspension/steering systems, wheels and tires, etc etc....The only thing I can think of at this point is the Viscous Coupler binding in the tail housing of the transmission....Does it only do this "bumping" when its warmed up? Take your car to a parking lot and do some figure eights and see if you can get it to do it...Does it feel like the whole car vibrates at all?

**oguitar** · 05-18-2010 04:36 AM

How are you running with out any o2 sensors?

**blest** · 05-20-2010 11:27 AM

Originally Posted by EvoEatr

If you said you checked everything in the suspension/steering systems, wheels and tires, etc etc....The only thing I can think of at this point is the Viscous Coupler binding in the tail housing of the transmission....Does it only do this "bumping" when its warmed up? Take your car to a parking lot and do some figure eights and see if you can get it to do it...Does it feel like the whole car vibrates at all?

After you threw this out there did some research... after doing a little reading im 99% sure this is the problem. The whole car definitely vibrates, and it does not do it when it is cold, only when the car has been driven for a bit. Does this still sound like the viscous coupler would be the problem? based off what i have read about it sounds like it has to be it.. thank you for the help! sorry about the delayed response. any further input is greatly appreciated, however at this point im pretty convinced viscous coupler has to be the problem. Again thanks for the knowledgeable response!

**blest** · 05-20-2010 11:30 AM

Originally Posted by oguitar

How are you running with out any o2 sensors?

um.. rich. LOL

(catless up pipe & turbo back)

**EvoEatr** · 05-20-2010 03:56 PM

Originally Posted by blest

After you threw this out there did some research... after doing a little reading im 99% sure this is the problem. The whole car definitely vibrates, and it does not do it when it is cold, only when the car has been driven for a bit. Does this still sound like the viscous coupler would be the problem? based off what i have read about it sounds like it has to be it.. thank you for the help! sorry about the delayed response. any further input is greatly appreciated, however at this point im pretty convinced viscous coupler has to be the problem. Again thanks for the knowledgeable response!

No prob. man, I dont want to say this is a common problem with Subarus because it is not however the longevity of the Viscous Coupler unit ( Center diff ) greatly depends on maintence of the vehicle, main thing is checking tire pressures and keeping up on tire rotations...From the information you have provided thus far it does sound that a binding VC is your prob. fortunately you can leave the transmission in the vehicle to replace this, though the part ( at least here in the states is around $550-700). Make absolute sure this is your prob though before you go just replacing things....

**Crb03** · 05-20-2010 04:24 PM

Theres a o2 sensor in your headers before the uppipe. You probably took out one in the tbe and up.

**blest** · 05-20-2010 08:16 PM

Originally Posted by Crb03

Theres a o2 sensor in your headers before the uppipe. You probably took out one in the tbe and up.

haha fair enough this is true.. however my point was that they're not all there, causing my CEL to be on at all times. guess i should have been more specific, i was just speaking for the parts that i had replaced/modified.

**blest** · 05-20-2010 08:30 PM

Originally Posted by EvoEatr

No prob. man, I dont want to say this is a common problem with Subarus because it is not however the longevity of the Viscous Coupler unit ( Center diff ) greatly depends on maintence of the vehicle, main thing is checking tire pressures and keeping up on tire rotations...From the information you have provided thus far it does sound that a binding VC is your prob. fortunately you can leave the transmission in the vehicle to replace this, though the part ( at least here in the states is around $550-700). Make absolute sure this is your prob though before you go just replacing things....

haha yes i definitely plan on going through all other possibilities one more time before spending the $550+. im just happy i dont have to drop the trans to replace it, as i agree that this is very likely the problem from what i've read. whole new headache hopefully avoided right there lol. Thanks again for the great response.