Rough Idle Continues

I've got a rough idle while the car is in D or R. While not in gear the motor feels pretty smooth.

 

What I've done:

 

-Replaced air filter

-Swamped coil packs

-Clean MAF Sensor

-Replaced Intake Manifold Gaskets

-Raised Idle RMP to 100+ and 125+ with A/C

 

I'm at a loss what to do next.

 

Thoughts?

Failed to mention zip tied everything I could find.

I've also run red line and chevron fuel/injector cleaners.

It will most likely turn out to be your oil control valves (OCV) I was dealing with the same issue, they help control the valve timing and can really screw with your idle and make the car idle like crap. You may want to make sure your TMIC is not starting to fail. Signs are it would look oily/dirty on the passenger side near the bottom. Hope this helps, also some people have said you can clean the OCV's as a band-aid. I had no luck with this but after replacement of both the car has run like a dream.

Do we know the parts numbers?

are you getting any fault codes? usually stuck ocv units throw specific codes.

are you getting any fault codes? usually stuck ocv units throw specific codes.

 

+1.

 

OP, have you done a compression / leak down test?

this will get you what you need at a good price, the dealer retail is about twice this price.

http://www.fredbeansparts.com/subaru-legacy-gt-oil-control-valve.html

are you getting any fault codes? usually stuck ocv units throw specific codes.

 

No codes.

 

+1.

 

OP, have you done a compression / leak down test?

 

No, but I will Wednesday. I have minor smoke coming out of oil fill cap at idle. It's too faint to see on a camera.

 

So in the mean time I pulled driver side OCV and cleaned it. Passenger side cannot be easily removed. No change in idle of course.

Passenger side cannot be easily removed. No change in idle of course.

 

I believe there is a trick to take that one out. It is described on the forum. See below.

 

What I did was pulled the passenger side OCV (under the intake tube, exactly opposite the drivers side pictured in the thread above) by removing the bolt and harness, sliding it half way out, rotating it 90* CCW looking at it from the front, then wiggling it past the support bracket.

Well maybe you can see it

 

[ame=http://www.youtube.com/watch?v=rYM_YHpBcII]05 Legacy GT Minor Smoke at idle - YouTube[/ame]

Well maybe you can see it

 

05 Legacy GT Minor Smoke at idle - YouTube

 

Oh crap, I can see it . I hope I am wrong but it does look like ringland issues. compression and leak down tests are in order IMHO.

Oh crap, I can see it . I hope I am wrong but it does look like ringland issues. compression and leak down tests are in order IMHO.

 

You had a bad idle as well. Did you have smoke like this?

 

I see you had a tight valve. When they pulled your motor why didn't you upgrade the pistons?

You had a bad idle as well. Did you have smoke like this?

 

I did not do the test myself BUT the mechanic did. I asked him about it and he said there was no smoke.

 

I see you had a tight valve. When they pulled your motor why didn't you upgrade the pistons?

 

Cause I have a family to feed and am pretty tight on budget right now. So goal was to get the car back on the road with minimum expense if possible.

I did not do the test myself BUT the mechanic did. I asked him about it and he said there was no smoke.

 

 

 

Cause I have a family to feed and am pretty tight on budget right now. So goal was to get the car back on the road with minimum expense if possible.

 

Makes sense. I send the little ones out on the street to fend for themselves

Makes sense. I send the little ones out on the street to fend for themselves

 

. Well, like I said I hope I am wrong. Good luck and keep us posted.

Well it was just dropped off. Crossing my fingers it's not a motor rebuild.

crossing my fingers it's not a motor rebuild.

 

+1.

It couldn't be worse and I cannot explain it.

 

Warm motor

Cyl 1 & 3 ~110psi

Cyl 2 & 4 ~80 psi

 

There is rust in cylinders and the plugs are fouled. I've not lost any coolant so I'm stumped.

 

Local shop is quoting $4,400 for a rebuild motor with forged pistons and some other performance goodies to better handle stage 2.

.

 

That's interesting. Weird...

 

So which route will you go?

 

How many miles do you have on your engine and how long have you been stage 2?

Did they perform a leak down test?

.

 

That's interesting. Weird...

 

So which route will you go?

 

How many miles do you have on your engine and how long have you been stage 2?

 

Not sure the route yet, I'd rebuild the block with better parts. Debating doing it myself but life is hectic right now.

 

98k on the motor, 38K that I've owned it, 10K that I've been driving it (ex-wifes car prior). Stage 2 maybe 2K.

 

All the plugs are covered in rust, pictures to follow, cylinders are nearly shiny and the top of the cyl walls are showing rust.

 

The direct cause won't be known until the motor is tore apart, since I'm not consuming coolant.

 

Did they perform a leak down test?

 

No they didn't bother on the account it's both sides and there is rust.

 

I suspect the motor had been overheated prior to our purchasing it.

I know this is a bit depressing to find out these kinds of things, but think of it as 'mod time' . My engine just got rebuilt (well just the heads really) and MAN it feels so nice and it is just stock (for now ).

I wish you the best of luck.

No codes.

 

 

 

No, but I will Wednesday. I have minor smoke coming out of oil fill cap at idle. It's too faint to see on a camera.

 

So in the mean time I pulled driver side OCV and cleaned it. Passenger side cannot be easily removed. No change in idle of course.

 

Sounds like a possible busted ring land for sure.

 

Your tests didnt show it being too low but should be closer to 135-150 psi so I ringlands are the issue.

 

If you rev the motor at idle does the smoke get worse?

 

You can definitely see it in your video.

Sounds like a possible busted ring land for sure.

 

Your tests didnt show it being too low but should be closer to 135-150 psi so I ringlands are the issue.

 

If you rev the motor at idle does the smoke get worse?

 

You can definitely see it in your video.

 

Didn't bother with that test.

 

The motor is being rebuilt now.