SOLVED: Very rough idle, diagnostic code P0018

[Evo_Fucking_STi]

I will tell you that the part numbers and parts are different from the 08-09 sti to a 10+. IF the motor has o8-09 heads it would take those ocv's if it has heads from a 10+ it would take the shorter ones.

 

[Deek]

Re: Very rough idle, diagnostic code P0018

I will tell you that the part numbers and parts are different from the 08-09 sti to a 10+. IF the motor has o8-09 heads it would take those ocv's if it has heads from a 10+ it would take the shorter ones.

Incorrect, I am at dealer right now, part numbers for the intake cam OCVs on the MY2008 STi engine are identical to the intake cam OCVs on the MY2010 STi engine. They brought out Subaru mechanic and we discussed, he also confirmed the intake cam OCVs found in the MY2010 STi engine weren't the correct components.

Now I need to pull the exhaust cam OCV assemblies to make sure those are correct too.

 

[Deek]

Re: Very rough idle, diagnostic code P0018

How the fuck did that engine end up with "incorrect" AVCS solenoids....

I have no idea, I should be asking you that.

 

[Deek]

Even better question is how was I able to tune AVCS on this car with ZERO issues and then Derek breaks it. WTF Man, you're one upping me on breaking shit.

We tuned with it too... I'm guessing that over time it failed because the 3rd hole on the bottom was just pressurizing oil into the AVCS cylinder wall. We'll see if this is the actual culprit soon enough, waiting to get some dinner in me then heading out to the garage.

Also, I don't know about the one upping bit... your transmission fiasco was pretty phenomenal. God help anyone within a 1 mile radius if I really do one-up you on breaking shit... "Going postal" doesn't begin to describe the level of rage that will put me at.

 

[Deek]

Alright, I put the proper intake cam OCVs in the MY2010 STi engine (the one in my car), cleared the codes and fired it up. I let it get to temp for about 3-5 minutes, it seemed fine. The other night it did the same, but then after turning it off and back on, I got crap idle again.


So, I turned it off then back on... it idled fine for 2 minutes. I did this three times, on the third I drove a couple miles and came back to see how it would idle in the garage. Still no idle issue, could this be solved?


I'm going to clean up and head out to Sonic in Cat City, where we all go on Thursday, so we'll see how things go.

 

[Evo_Fucking_STi]

Incorrect, I am at dealer right now, part numbers for the intake cam OCVs on the MY2008 STi engine are identical to the intake cam OCVs on the MY2010 STi engine. They brought out Subaru mechanic and we discussed, he also confirmed the intake cam OCVs found in the MY2010 STi engine weren't the correct components.

Now I need to pull the exhaust cam OCV assemblies to make sure those are correct too.

08-09 ocv is part number 10921aa080 no super session build date of 2010-01 and up is part number 10921aa140. I have both in hand and they are different.


The exhaust are the same however. Part number 10917aa070 is driver side and 10917aa060 is passenger side

 

[Deek]

08-09 ocv is part number 10921aa080 no super session build date of 2010-01 and up is part number 10921aa140. I have both in hand and they are different. View attachment 3638


The exhaust are the same however. Part number 10917aa070 is driver side and View attachment 3639 10917aa060 is passenger side

Pictures are too small to tell what they say. I'm not doubting that's what the computer says though, just saying it seems wrong. Why would they leave the hole pattern in the AVCS cylinder (4 on top, 2 on bottom) the same and put in an OCV that has 3 holes on top and 3 on bottom?

I do know that when we looked up the parts in the computer at the local dealer, they were the same for both MY2008 and MY2010... 10921AA080.

If we ignore that fact, then the only possible explanation is that when Edwin had this motor built, the builders put 08-09 heads on his MY2010 engine.

Update, no issues tonight while cruising around, or idling at Sonic. I'm hopeful that this is all sorted out now, seems so. We'll see what tomorrow brings.

 

[Grinder34]

I'm hoping you got it all figured out. Sounds promising.

 

[Deek]

So far so good. I'm comfortable enough at this point stating that my issue was that the wrong intake OCVs were installed and over time one failed because the third hole on the bottom was just pressurizing oil into the AVCS cylinder wall.


Drove around a bit the past couple days without incident. Next oil change I'll need to verify that the proper exhaust OCVs are installed. :lol:

 

[Evo_Fucking_STi]

I was giving you build dates, If you look at the build date, it till tell you the differences. Any AVCS head built after january 2010 will require the 3 hole top 2 hole bottom OCV. It could be a mid production switch. Subaru does this quite often. It drives me nuts!

 

[Deek]

Re: Very rough idle, diagnostic code P0018

I was giving you build dates, If you look at the build date, it till tell you the differences. Any AVCS head built after january 2010 will require the 3 hole top 2 hole bottom OCV. It could be a mid production switch. Subaru does this quite often. It drives me nuts!

That still doesn't explain the OCVs that were in the engine, they had 3 on top and 3 on bottom.