'07 Liberty GT-B severe hesitation / Misfire

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'07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Mon May 18, 2015 11:52 pm

Hi all.

Done a search and gone through numerous threads each with different endings regarding similar/same problems that I'm experiencing.

I thought I'd create a new thread in order to, with all of your help, build a comprehensive check list for myself and others who may have the same issue!

Car:

Libery GT spec B 2.5T 6-speed manual 2007 model. Full Subaru service history. 130,000KM
No engine CEL on dashboard

Symptoms:

1) While stationary engine warm, holding the revs up to around 1500RPM, the car will briefly sound like it is slightly missing & the engine will shake more than usual (noticeable in cabin), then regulate itself after 2-3 seconds. If you back off the gas to idle, and repeate it a few times, it'll do it again. Probably 1 in 5 times results in the aforementioned Misfire like symptom. It's a little tricky to get it to show this symptom.

2) while driving in stop start traffic, engine warm, the car will occasionally "bunny hop" or shudder. it is sometimes quite violent, almost undrivable, sometimes it is more gentle and noticeable. This occurs when the car overruns to 1300/1500 rpm, slowing down naturally, then accelerating. It happens when you accelerate from slow speeds around 1500 rpm essentially. Think of someone falling off a clutch when learning to drive. FYI I am not using the clutch at all in this scenario. This issue seems worse in Intellegent mode, and slightly better in sport mode.

3) hesitation on boost. When going to WOT from 2500-ish rpm, the car will climb but hesitate and stumble as it makes boost. It doesn't come on smooth. Third gear seems smoother than second. If you go to WOT from say 4000 RPM, it is less noticeable and seems to come on strong.

Thoughts

1) could be one issue or a bunch of small issues.

Fix list.

1) ordered 2 x OCV solenoids for Intake VVT
2) ordered 4 x OEM spark plugs
3) remove screen / filter from drivers side, engine head side banjo bolts.

What else could it be?

1) EGR needs cleaning?
2) coilpacks?
3) Blocked head side banjo bolt for Passenger solenoid oil feed?

I'm thinking of pulling the timing belt off to remove the screen from the passenger side solenoid oil feed. The last thing I want to do is replace a solenoid and have it fail again due to starvation!

Do the solenoids fail over time or fail due to oil starvation?

Thoughts?

Please feel free to add your known / potential fixes and I will tick them off one-by-one and see if it resolves the issue.

Thank you all in advance for any help you can provide.
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby KiDo_Tuning » Tue May 19, 2015 5:26 am

No EGR's on these cars so it wont need cleaning
Coil packs are unlikely but yes they can cause same issue
No blockages possible in the banjo bolt as they no longer run a filter. Gunk ends up in cam gear
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Tue May 19, 2015 8:22 am

KiDo_Tuning wrote:No EGR's on these cars so it wont need cleaning
Coil packs are unlikely but yes they can cause same issue
No blockages possible in the banjo bolt as they no longer run a filter. Gunk ends up in cam gear


Thanks for the quick reply mate!

So just to confirm,

1) There is no banjo bolt filter at all? Not even on the engine head side of the banjo bolts? I know there are two bolts, one banjo bolt driver's side that feeds solenoid and turbo and one passenger side behind the timing cover that feeds just the solenoid. If there's no filters there, that's awesome!

2) does the belt come off to clean the cam gear? Are they cleanable?


Thank you once again :)
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby bigBADbenny » Tue May 19, 2015 9:00 am

Where are you located? You might have a local willing to diagnose with a btSsm or Tactrix.

Just start with the easy stuff:
- clean or replace the engine air filter
- clean the MAF sensor with eg CRC MAF cleaner aerosol.
- injector cleaner, then UEC..
- consider an engine oil flush too.
- oil change
- replace the OCV's.

Yes, AVCS cam gears can be cleaned but its something to do or to replace at a timing belt service.
http://forums.nasioc.com/forums/showthr ... ?t=2713834



As for banjo filters, see my comments in this helpful thread:
viewtopic.php?f=10&t=30105&p=407081#p407081
Once again, something easy to check when you have the inlet pipe off or the LHS inlet cam gear off.

Replacing or cleaning the cam gears is fairly rare, the only time it's been done recently was an OzFoz member whose cam gears were damaged in the process of fitting upgrade cams, or they got jammed due to debris from a spun bearing. I sold him my spare gears, which fixed the issue, along with new OCV's.
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Tue May 19, 2015 10:28 am

bigBADbenny wrote:Where are you located? You might have a local willing to diagnose with a btSsm or Tactrix.

Just start with the easy stuff:
- clean or replace the engine air filter
- clean the MAF sensor with eg CRC MAF cleaner aerosol.
- injector cleaner, then UEC..
- consider an engine oil flush too.
- oil change
- replace the OCV's.

Yes, AVCS cam gears can be cleaned but its something to do or to replace at a timing belt service.
http://forums.nasioc.com/forums/showthr ... ?t=2713834



As for banjo filters, see my comments in this helpful thread:
viewtopic.php?f=10&t=30105&p=407081#p407081
Once again, something easy to check when you have the inlet pipe off or the LHS inlet cam gear off.

Replacing or cleaning the cam gears is fairly rare, the only time it's been done recently was an OzFoz member whose cam gears were damaged in the process of fitting upgrade cams, or they got jammed due to debris from a spun bearing. I sold him my spare gears, which fixed the issue, along with new OCV's.


Hey mate, thanks foe responding. I am located in Sydney.

Regarding the banjo bolts, did you ever check the one under the turbo inlet on the head and find a filter there?

- will check the engine air filter today
- cleaned the maf last night with no luck
- Have filled up tank with the Subaru fuel additive at the moment, when this tank is done I'll run injector cleaner
- will get UEC tomorrow
- flushed oil already and changed
- OCV on their way

Today it was quite bad..:(

Also, is there a way to check CELs without a reader? I went into the drivers kick panel and found two wires, green connected, white not connected. I disconnected the green one as I thought this was some read mode ecu thing? Cheers
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby bigBADbenny » Tue May 19, 2015 1:32 pm

Great, sounds like you're ready for the install then.
Some Subies can display CELs on the trip computer display, but I never tried it on my postFL so not sure.
You can read CELs with a $15 ELM327 adapter and the Torque app amongst others, need an Android with BT.
http://www.ebay.com.au/sch/i.html?_odkw ... i&_sacat=0
IIRC iPhone compatible wifi OBDII plugs are available as well, ymmv.
http://www.ebay.com.au/sch/i.html?_odkw ... i&_sacat=0
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Tue May 19, 2015 1:45 pm

bigBADbenny wrote:Great, sounds like you're ready for the install then.
Some Subies can display CELs on the trip computer display, but I never tried it on my postFL so not sure.
You can read CELs with a $15 ELM327 adapter and the Torque app amongst others, need an Android with BT.
http://www.ebay.com.au/sch/i.html?_odkw ... i&_sacat=0
IIRC iPhone compatible wifi OBDII plugs are available as well, ymmv.
http://www.ebay.com.au/sch/i.html?_odkw ... i&_sacat=0


You're a star mate, thanks for those.

Sorry to be a pain and ask 50 times, but did you ever personally pull of the head side banjo bolt under the intake of the turbo on your car? I know there are no screens solenoid / turbo side. But still think they're on the head side for some reason?

Just want to be sure there is screens on engine side before I rip my timing belt off lol.
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby bigBADbenny » Tue May 19, 2015 6:58 pm

You'd have to ask someone who tears these engines down often.
But as far as we know, based on basic research, mostly from US sites eg LGT, the 2.5T has them behind the LHS inlet cam gear, and on top of the block under the turbo inlet tube.
They're there for a reason, eg if you spin a bearing, it can keep debris out of the turbo and ocv's.
They can also be removed with no ill effect.

If there is a filter, its at points 3 (x2) in this diagram.
http://opposedforces.com/parts/legacy/e ... tration_1/
Intriguingly the RHS oil supply line in the diagram looks more like what you'd find on a preFL, with the union screw on the back of the LHS head.
I'll check my spare block next time I'm at the garage, where its sleeping in a container.

PreFL RHS style:
http://legacygt.com/forums/showthread.p ... ?p=2377798

PostFL RHS EJ255:
http://legacygt.com/forums/showthread.p ... l?t=200717

PostFL LHS EJ255: see the re re re post of HammerDowns filter fun.
http://legacygt.com/forums/showthread.p ... 89p71.html

But don't stress, 99.99% its going to be your OCV's. Chances are... there are no filters in the postFL 2.5T.

I feel for you, my car was the same when I bought it at 150K: shithouse.



A few Throttlehappy tunes, 2x new OCV's, 3" tbe, pump, filter, airfilter, STS, ShockWorks and some other junks later its an on-point dream boat!




.
Last edited by bigBADbenny on Tue May 19, 2015 7:26 pm, edited 1 time in total.
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby dr20t » Tue May 19, 2015 7:23 pm

Check front and rear 02 sensors first

Then check for boost/ vacuum leak

Then if all above are ok then check ocv's
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby bigBADbenny » Tue May 19, 2015 7:27 pm

IE get hold of a tactrix or BtSssm asap.
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Wed May 20, 2015 8:22 am

Awesome! Thanks for all your help, it's good to see a supportive community.

Partsouq have posted my solenoids. I will try get to everything else over the weekend.

I have been giving it a bit of stick and it's getting better in sport mode. I'll try Intellegent mode on the way home today.
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Wed May 20, 2015 12:55 pm

bigBADbenny wrote:IE get hold of a tactrix or BtSssm asap.


I can log VVT with BTSsm and a Bluetooth OBD dongle?
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Thu May 21, 2015 2:08 pm

Car threw an engine light today.

Will read the code tonight!!
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby dr20t » Thu May 21, 2015 3:29 pm

Bronald wrote:Car threw an engine light today.

Will read the code tonight!!


$50 says its front or rear 02
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Re: '07 Liberty GT-B severe hesitation / Misfire

Postby Bronald » Thu May 21, 2015 5:19 pm

dr20t wrote:
Bronald wrote:Car threw an engine light today.

Will read the code tonight!!


$50 says its front or rear 02


You owe me 50$

Image

Can anyone help identify possible causes for the other codes? I've reset them and not seem them since.
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