[Ryan J. Geyer]

Hello all,

I picked up my first Subaru a bit over a year ago, and it's been great aside from one ongoing issue, which seems to be getting progressively worse. The car is 100% stock AFAIK

A little history..

When I first bought the car, it ran a bit rough at idle occasionally but nothing unbearable. This still happens. It also seemed to have a hesitation around 3k RPM under almost all throttle conditions (full throttle, part throttle, cruising etc). This hesitation seems to happen before boost really kicks in.

About 2 months ago, I started getting misfire codes and brought the car into a mechanic. After a few days of diagnosis they identified a vacuum leak in the form of a cracked intercooler, which I had replaced.

The car ran well after that, but still had the hesitation/stumble (feels like a misfire, or flooding) between off boost and on, around 3k RPM.

Very recently now, the stumbling has gotten worse (much worse) and I am also getting a P0244 CEL that is usually triggered at or near full throttle, under load. I've noticed it usually at higher RPMs, around redline. Sometimes it happens between shifts, but not always.

The mechanic had advised a transmission fluid flush before these problems developed, but I don't imagine that would cause this issue?

Any ideas on what might be going on here? It sounds a lot like several other threads I've read on tuned cars, but not necessarily in combination with the off boost stumble?

At any rate, happy to be a new Subaru owner and hoping I can work out this last gremlin.

 

[subiesailor]

Have you checked for play in the turbo shaft? The XT is a special animal turbo failure shedding metal bits into the engine is a common very costly failure when not checked when these types of things occur.

 

[eagleeye]

moved to 2005-2009 land

where all the problem child XT, car problems exist.

 

[relative4]

Could be boost control hoses, boost control solenoid, wastegate, actuator. Smoke test the boost control hoses and the rest of the intake system, check wastegate operation, pressure test actuator.
Prior to all that, learned values and maybe a logged pull would be very helpful.

 

[cardoc]

Especially a log

 

[Ryan J. Geyer]

moved to 2005-2009 land

where all the problem child XT, car problems exist.

Hey! Thanks for all the quick responses, and sorry I didn't respond sooner. I didn't setup my notification properly and didn't realize anyone responded, and couldn't find my post cause it'd been moved

Have you checked for play in the turbo shaft? The XT is a special animal turbo failure shedding metal bits into the engine is a common very costly failure when not checked when these types of things occur.

Nope, haven't really looked at anything yet, was hoping to get some recommendations. I'll take a peek at this. What am I looking for, fore-aft play along the length of the turbo shaft, or more like ovaling of the bearings?

Could be boost control hoses, boost control solenoid, wastegate, actuator. Smoke test the boost control hoses and the rest of the intake system, check wastegate operation, pressure test actuator.
Prior to all that, learned values and maybe a logged pull would be very helpful.

So, I wouldn't rule out a vacuum leak, but it seems highly unlikely. The mechanic who replaced my intercooler did a smoke test to find the crack in the intercooler, so I would expect that they'd have identified any other leaks as well. I'll double check, but I don't think I'll repeat the smoke test until I've ruled out some alternatives.

Especially a log

Right, so, I have a VAG-COM cable, and a laptop with FreeSSM, or my android device with BtSSM. Is there a generally accepted standard set of values to pull for logging? I think I've got the right tools, but not sure what would be of interest to monitor.

I can't seem to find a sticky anywhere for this, but maybe my searching skills are failing me.

Thanks guys!

 

[Ryan J. Geyer]

Correction based on a bit more research.

I also have RomRaider, which it seems would be the right thing to log with. Opening it up now to see if there's a standard logging format.

Forgive my ignorance, I started looking at this when I first bought the car, then subsequently forgot a lot of it

 

[eagleeye]

Correction based on a bit more research.

I also have RomRaider, which it seems would be the right thing to log with. Opening it up now to see if there's a standard logging format.

Forgive my ignorance, I started looking at this when I first bought the car, then subsequently forgot a lot of it

read @traildogck 's various threads on it,...he owns a 2005 and a 2006 XT.

he has another thread about what to log.
http://www.subaruoutback.org/forums/66-problems-maintenance/97977-romraider-what-data-log.html

and
http://www.subaruoutback.org/forums...184122-reading-flashing-your-ecu-dummies.html

______


some people can't get the log screens to work, so just use the ECU editor one for logging.

 

[Ryan J. Geyer]

Okay, last follow up for now...

I've got RomRaider all up and running, but it does want me to select which sensor values to log. Not sure if I should just grab "everything" or some select set.

I am quite sure I won't be able to sift through all of the data if I log everything...

 

[subiesailor]

Hey! Thanks for all the quick responses, and sorry I didn't respond sooner. I didn't setup my notification properly and didn't realize anyone responded, and couldn't find my post cause it'd been moved



Nope, haven't really looked at anything yet, was hoping to get some recommendations. I'll take a peek at this. What am I looking for, fore-aft play along the length of the turbo shaft, or more like ovaling of the bearings?



So, I wouldn't rule out a vacuum leak, but it seems highly unlikely. The mechanic who replaced my intercooler did a smoke test to find the crack in the intercooler, so I would expect that they'd have identified any other leaks as well. I'll double check, but I don't think I'll repeat the smoke test until I've ruled out some alternatives.



Right, so, I have a VAG-COM cable, and a laptop with FreeSSM, or my android device with BtSSM. Is there a generally accepted standard set of values to pull for logging? I think I've got the right tools, but not sure what would be of interest to monitor.

I can't seem to find a sticky anywhere for this, but maybe my searching skills are failing me.

Thanks guys!

The very basic concept is play in the shaft supporting the turbo blade resulting in the blades contacting the housing chipping off bits of metal which then get ingested by the engine. Its a very typical failure and very costly one.

 

[traildogck]

Especially a log

This

 

[relative4]

Right, so, I have a VAG-COM cable, and a laptop with FreeSSM, or my android device with BtSSM. Is there a generally accepted standard set of values to pull for logging? I think I've got the right tools, but not sure what would be of interest to monitor.

Post LV from BtSsm. Very quick and often very useful.

 

[Ryan J. Geyer]

Post LV from BtSsm. Very quick and often very useful.

So, I feel a bit foolish now, I pulled the learned values, and it's VERY obvious why I'm experiencing the performance issues I am. There are HUGE timing pulls at the RPMs I'm complaining about (see attached).

I reset the ECU and all the LVs returned to 0 of course, and the car is running great now.

So, the trick now is to figure out what is causing the P0244 which I believe is also causing the ECU to set those ludicrous LVs for huge timing retard.

read @traildogck 's various threads on it,...he owns a 2005 and a 2006 XT.

he has another thread about what to log.
http://www.subaruoutback.org/forums/66-problems-maintenance/97977-romraider-what-data-log.html

and
http://www.subaruoutback.org/forums...184122-reading-flashing-your-ecu-dummies.html

______


some people can't get the log screens to work, so just use the ECU editor one for logging.

Excellent, thanks eagleeye, I'll take a look at that.

The very basic concept is play in the shaft supporting the turbo blade resulting in the blades contacting the housing chipping off bits of metal which then get ingested by the engine. Its a very typical failure and very costly one.

Yuck, I'll take a look at this as well. Sounds like a good excuse to upgrade a turbo to me

 

[relative4]

Yikes! Those are the worst timing pulls I've ever seen. Looks like a massive boost leak. I'd get a smoke tester on that thing before pulling it out of the driveway again.

 

[Ryan J. Geyer]

Yikes! Those are the worst timing pulls I've ever seen. Looks like a massive boost leak. I'd get a smoke tester on that thing before pulling it out of the driveway again.

Is that the only likely cause of timing pull?

I'm not ruling out a boost/vacuum leak but.. Less than six months ago the car had a smoke test done, which revealed a cracked intercooler, which was replaced.

I really want to believe the garage that did the work would have noticed any other leaks as well.

I'll take a peek to see if there are any obvious busted vac lines etc.

What's the normal idle vacuum? Before the ECU reset, I was seeing not more than -8 psi, and after it was not more than -11 psi (logs attached).

The "after" log is a 3rd gear pull from the lowest rolling RPM I could manage on the highway.

 

[Ryan J. Geyer]

Ohh right, I forgot to mention. I'm roughly at sea level.. ~100ft elevation

 

[relative4]

Is that the only likely cause of timing pull?

Not at all. However, you're lean at idle and rich at boost, with a steady progression between the two ends. THAT says boost leak. Intercooler, IC-TB hose, manifold. My money's on another split TMIC. Did they just replace with OEM without bulletproofing it?

I'm not ruling out a boost/vacuum leak but.. Less than six months ago the car had a smoke test done, which revealed a cracked intercooler, which was replaced.
I really want to believe the garage that did the work would have noticed any other leaks as well.

I would want to believe that too, but if it took them days of diagnostics to find a split intercooler, they know nothing about turbocharged Subarus.

I'll take a peek to see if there are any obvious busted vac lines etc.

Waste of time. Get a smoke tester and find the leak.

What's the normal idle vacuum? Before the ECU reset, I was seeing not more than -8 psi, and after it was not more than -11 psi (logs attached).

Boost numbers are not a really great way to look at manifold vacuum. If you want to get a feel for that, get a vacuum gauge and read this:
Technical Articles: Engine testing with a Vacuum Gauge - at Greg's Engine & Machine

The "after" log is a 3rd gear pull from the lowest rolling RPM I could manage on the highway.

Several more columns would be needed to make a log really useful, but I'm not going to discuss those because you should not be boosting until you fix that leak. Your IAM is ZERO. The ECU is working overtime to prevent you from blowing your engine. Be smart.

 

[traildogck]

Not at all. However, you're lean at idle and rich at boost, with a steady progression between the two ends. THAT says boost leak. Intercooler, IC-TB hose, manifold. My money's on another split TMIC. Did they just replace with OEM without bulletproofing it?

I would agree with the above.

Both of my stock TMICs had end tank leaks. I repaired both (with my own brand of bullet-proofing) JBWeld. Then went on to replace them both with solid aftermarket.

 

[hero2zero]

I'll second the boost leak assessment. Here is some good reading on all the suspect areas ripe for failure:

http://legacygt.com/forums/showthread.php/intake-vacuum-leaks-and-you-pics-inside-235626.html

 

[traildogck]

I'll second the boost leak assessment. Here is some good reading on all the suspect areas ripe for failure:

http://legacygt.com/forums/showthread.php/intake-vacuum-leaks-and-you-pics-inside-235626.html

This link is full of the critical leak sources on an aged XT. It is very well done.

CryoTune has a very good reputation.