[super7pilot]

Hi all, Bought a 2019 Crosstrek 6 speed last October 2018. After about a month while driving. Noticed a sudden and dramatic loss of engine power. This went on for 10-15 minutes. Odd thing is that while it lost power. It was still running smoothly. it has done this 5 times in the last year. NO CEL.
It has done this on flat terrain at 70 degrees. In the rain at 62 degrees. Pulling a 4-5% grade in 97 degrees. Tank almost empty as well as after just filling up.
So far Subaru has said. Unless there is a fault code, We can't do anything. Then they had a the gall to say: Just drive until it breaks.
This is BS. We do a lot of traveling in our coach and tow the Subaru behind it.
Total miles on the car in the last year is 8,000 as I do not like it at all and drive our 2003 Legacy Wagon as it has better power and drives better as well.

 

[br4zzz]

I believe I have the same issue as you. I dont experience a dramatic loss of power but the car does seem to bog down a bit usually in 2nd and 3rd gear around 2500 RPM and tends to clear up right at 3000 RPM. Im just under 8000 miles with a 2019 6MT. Ive heard of others experiencing the same issue on the Crosstrek FB page. I took the car into the dealership today, they couldn't really replicate it but did reset the ECU. So far it seems okay but maybe others can chime in?

 

[super7pilot]

I suspect that it is one of two things.
1, A software issue. But it seems odd that it would have happened just 5 times in 8K miles. And under such variable conditions.

2, A sensor issue. Perhaps the O2 exhaust sensor is out of range on the voltage it sends to the fuel injection. But not enough out of voltage range to log a fault.

As it's so intermittent. It's always a tough one. And truth be told. The mechanics these days have about ZERO diagnostic skill. If the computer doesn't say there is an issue, Then the modern mechanic will just parrot that there is no issue.

 

[R P]

I have a CVT and one time by accident had it in M mode (for using the paddle shifters). For a minute, I wondered what was wrong, that it seemed to bog down at lower rpm. I quickly noticed my problem and moved the shift lever over to the right (auto), and the CVT immediately found the proper rpm for the acceleration demand I was giving it with the throttle. It took off normally after that. Seems this engine doesn't like a lot of throttle at low rpm (in manual mode).

 

[super7pilot]

I have a CVT and one time by accident had it in M mode (for using the paddle shifters). For a minute, I wondered what was wrong, that it seemed to bog down at lower rpm. I quickly noticed my problem and moved the shift lever over to the right (auto), and the CVT immediately found the proper rpm for the acceleration demand I was giving it with the throttle. It took off normally after that. Seems this engine doesn't like a lot of throttle at low rpm (in manual mode).

Big difference though from yours. When I'm driving at 45-50 and need to downshift twice and keep my foot nearly to the floor to keep it at 35. That's an issue.

Even on flat terrain when I was doing 60MPH in 5th. It took a long, long time to even gain 2 MPH. That's a serious issue.

And too think I gave up a 2014 Mercedes 2 liter twin turbo Diesel AWD & 40-45MPG for this POS. All Because the Mercedes couldn't be flat towed and I got tired of having to load it on a trailer. And I have heard so much about the alleged Subaru goodness. I wish I had the GLK back.

 

[irv_usc]

that sounds weird. on an older car I had a similar issue to what you're describing, it turned out to be an issue with the throttle position sensor. Not sure about the Crosstrek since everything is computerized these days.

 

[super7pilot]

that sounds weird. on an older car I had a similar issue to what you're describing, it turned out to be an issue with the throttle position sensor. Not sure about the Crosstrek since everything is computerized these days.

Good call. I'll ask the dealer to check that out.
TPS and an electronic throttle pedal are essentially the same thing but in different locations. Just potentiometers. My 1998 motor coach has an electronic pedal as the 11 liter Cummings is 30 feet behind my steering wheel.

 

[irv_usc]

one way to check (be sure traffic is clear) when this problem arises is to throw it in neutral and see if it revs up like normal. I'm not sure the computer diagnostic stuff the dealer does would detect it unless it was currently having the issue.

 

[super7pilot]

That's the trouble with the ECU's and their programing/diagnostics. It might not be in total failure (yet) and just doesn't meet the programed threshold of throwing a code. That's why I thought it could be the O2 sensor. It could be sending the wrong voltage rather than just not sending voltage like if it just stops working.

Most TPS and APP's will throw a fault if they stop working. But what about when they are still working and just sending the wrong voltage.

I'd say your correct on the dealer not seeing it until it's coded or happening while on a test drive. But with this issue coming up on average of every 1600 miles. It's just a shot in the dark for this to come up during a technician test drive.

 

[eirual]

Same thing here. 2019 Crosstrek Premium 6MT. Loss of power when shifting to 3rd or 4th. Took it to the dealership and was told to switch to premium gas and to consistently run the car until the low fuel light came on (which I find odd).

I am also randomly experiencing engine knock in the middle of the summer, which is unusual.

 

[super7pilot]

that sounds weird. on an older car I had a similar issue to what you're describing, it turned out to be an issue with the throttle position sensor. Not sure about the Crosstrek since everything is computerized these days.

Talked to the shop about throttle pedal position sensor. Said it was very, very unlikely. Said the computer is setup to throw a code at a very low threshold I.E. super sensitive. As losing throttle control is a rather big deal. A fault will show even if the voltage simply varies in a nonlinear way like a dead spot.
So back to square one.

 

[super7pilot]

Same thing here. 2019 Crosstrek Premium 6MT. Loss of power when shifting to 3rd or 4th. Took it to the dealership and was told to switch to premium gas and to consistently run the car until the low fuel light came on (which I find odd).

I am also randomly experiencing engine knock in the middle of the summer, which is unusual.

Engine knock in an engine that is fueled with the factory recommended grade has got to be a software (ignition advance) issue. Premium might help. But that's like taking care of a broken leg by taking opioids and not having it set and a cast put on. The pain may go away, But the cause of the pain is still there.

 

[Diesel Nine]

I suspect that it is one of two things.
1, A software issue. But it seems odd that it would have happened just 5 times in 8K miles. And under such variable conditions.

2, A sensor issue. Perhaps the O2 exhaust sensor is out of range on the voltage it sends to the fuel injection. But not enough out of voltage range to log a fault.

As it's so intermittent. It's always a tough one. And truth be told. The mechanics these days have about ZERO diagnostic skill. If the computer doesn't say there is an issue, Then the modern mechanic will just parrot that there is no issue.

I think Subaru must have farmed-out some of software issues to the Boeing folks who helped certify the B-737 Max. Well, not quite that bad, but you get the drift. I've been feeding my 2015 Forester premium fuel since about a year after I got it.... great engines, but need some TLC>

 

[eirual]

Engine knock in an engine that is fueled with the factory recommended grade has got to be a software (ignition advance) issue. Premium might help. But that's like taking care of a broken leg by taking opioids and not having it set and a cast put on. The pain may go away, But the cause of the pain is still there.

That's exactly what I thought. The info I was told was odd - and I told them so. Will be bringing it back to have looked at again.

 

[Zbroussard]

I have data logs of this phenomenon. The ECU pulls a TON of timing and the MAF signal goes nuts. I'm satisfied that this is an ECU / software issue. This issue has never re-occured since I flashed an aftermarket map. If any of you experiencing this have the ability to data log it, it would probably go a long way in getting actual attention from Subaru. A brand new car falling on it's face at 2500rpm is not 'Normal'.

 

[eirual]

I have data logs of this phenomenon. The ECU pulls a TON of timing and the MAF signal goes nuts. I'm satisfied that this is an ECU / software issue. This issue has never re-occured since I flashed an aftermarket map. If any of you experiencing this have the ability to data log it, it would probably go a long way in getting actual attention from Subaru. A brand new car falling on it's face at 2500rpm is not 'Normal'.

What did you use to do the data logging?

 

[Zbroussard]

SubaruEdit by epifan. Not something cheap or easy to get if you don't have it already, but there may be other logging options?

 

[eirual]

SubaruEdit by epifan. Not something cheap or easy to get if you don't have it already, but there may be other logging options?

OK - I have OBDLink, I will do the logging with that. Thanks!

 

[wizzells]

Glad I stumbled across this thread.

I have the same symptoms that you all describe on my 2019 6MT.
It will bog/fall on its face around 2500 rpms, and act like it wont take throttle input. At times, will barely accelerate without downshifting to get the revs up over 3000. Worse with the A/C on. Seems to be heat related, at least in my case, as around town driving, especially in the summer heat seems to cause it.
I have a Scan Gauge, and while I can't data log, I can see that it will pull huge amounts of timing when this happens - like 8-10 degrees compared to when it's not "acting up". Fuel grade makes no difference, which makes me think it's not knock sensor signal related, whether it's 87 octane (E10), or non-ethanol premium (91-93). I do occasionally get spark knock, but that clears up with the higher grade fuel. But the bog does not.

Has anyone gotten anywhere with a dealer actually investigating the issue? Mine blew me off like I didn't realize that having the A/C on will rob some power from the engine. Yeah, no kidding...I'm a master certified tech on 2-wheels, but don't want to go the aftermarket calibration route for warranty reasons.
Just had the ECM reflash completed for the ignition coil recall - we'll see if they snuck some other updates in there to clear this up.

 

[Zbroussard]

I would be very curious to see if Subaru did address this with the reflash. I'm in a bit of a tight spot myself, in that I would like to get the warranty reflash to address the ignition coil issue, but I don't want to go back to the stock map. I also don't really want somebody going poke around looking at my flash count if I bring it in. I'd REALLY like to know exactly how common the coil issue is and what exactly is going on, but I doubt that info will ever come out. I'll probably just assume I don't have a problem and skip the warranty flash.

If it does not clear up with the reflash, I was able to regularly and reliably replicate the bog on a long hill in a 45mph zone. 4th gear around 2600 or so put it right around the speed limit and with enough throttle to put it right in the middle of the bog. Maybe you can find a similar stretch of road to repeatably induce it and get them to ride along?

But, I'm sure somebody will be along shortly to tell us that it's all completely normal, that it's the CVT acting at a distance on our 6MT cars, or that you need to run it up to 6000rpm to climb a gentle hill, and ask again if you had the AC on.... lol

Please let us know what you find!