What could be slippin'?

[wxlidar]

Here is the scenario: I back out of my driveway, come to a complete stop, shift into drive, wait a second or two (gotta let that CVT engage!) and then press the accelerator. Occasionally I get a 'buzz' or 'grunt' like something in the driveline is slipping and the car does not move. This will last anywhere from 0.5-2 seconds. The car then moves normally. I usually instinctively let off the accelerator when this happens but even if I don't there is no lurch or 'catch' when the car moves.

Any thoughts out what could be happening? It does seem like something is slipping or not engaging. It has happened a dozen or so times over the past year or two. Of course it doesn't do it when at the dealer...

Thanks for any suggestions.

[mcbrew]

Doesn't sound right... Unless you had the hill holder feature engaged. Also, it shouldn't take any longer to go from reverse to drive than your average automatic transmission. There might be something up with your trans.

[Pool Runner]

Op I recently posted a thread on this with my 2011, 2.5i, CVT. my symtoms are the same as yours. My problem happens only when the car has sat for a period of time like overnight. Get in and start car, put in reverse and there is this grunt as you apply throttle (feels like a manual trans as you let up on the clutch but slipping) our car has 22k miles on it today, but has done this 10-15 times since starting about 8-9k miles.

I've had the dealer look into it twice, even let dealer have the car for a week while we were on vacation to try and duplicate issue with no success. BTW I am extremely annoyed by the problem and fear a massive failure at some point although the drives good otherwise.

Service manager thinks that when the car is cold, the fluid hasn't fully pumped through CVT and or the cars differentials, but no further evaluations have been tried yet. Op keep me in the loop with your issue as I am desperately trying to figure this out before my wife is stranded on the side of the road and or my warranty is up.

[hallux]

Mine does the same thing, with only 14,000 miles on it. Pool Runner, I think your SM may be on track with the assessment, except I would think it only applies to the CVT and POSSIBLY the front diff, there shouldn't be a "fluid pumping" issue in a diff with no fluid pump.

[Pool Runner]

Originally Posted by hallux

Mine does the same thing, with only 14,000 miles on it. Pool Runner, I think your SM may be on track with the assessment, except I would think it only applies to the CVT and POSSIBLY the front diff, there shouldn't be a "fluid pumping" issue in a diff with no fluid pump.

Opps, yeah I realize there is no "pumping of oil" in any of the differentials. I guess I was thinking the center differential, the one that splits the torque or power from front to rear may have the clutch packs dry from sitting over night and that grunt and slipping feeling is the CVT trying to push the car against sticking clutch packs until the fluid lossens the clutch-packs. I really don't know what I'm saying as I really don't know as much as I wish I did about the AWD/ CVT in these cars.

My initial theory is that the fluid is not fully moving yet inside the CVT from sitting overnight cold or for a period of time. I asked my SA if they checked the factory fluid level and they said it was fine and in spec. I'm thinking I might change the fluid out on my own with a fully synthetic type.

[subiesailor]

Originally Posted by Pool Runner

Opps, yeah I realize there is no "pumping of oil" in any of the differentials. I guess I was thinking the center differential, the one that splits the torque or power from front to rear may have the clutch packs dry from sitting over night and that grunt and slipping feeling is the CVT trying to push the car against sticking clutch packs until the fluid lossens the clutch-packs. I really don't know what I'm saying as I really don't know as much as I wish I did about the AWD/ CVT in these cars.

My initial theory is that the fluid is not fully moving yet inside the CVT from sitting overnight cold or for a period of time. I asked my SA if they checked the factory fluid level and they said it was fine and in spec. I'm thinking I might change the fluid out on my own with a fully synthetic type.

CVT fluid is a special fluid don't mess with it!

What happens if you wait a second or two longer after starting the car before you put it into reverse or drive? Also your not hearing the parking brake release are you?

[hallux]

In my case I know it absolutely isn't the parking brake, it does it in a completely flat parking lot where I don't use the brake.

[Pool Runner]

Originally Posted by subiesailor

CVT fluid is a special fluid don't mess with it!

What happens if you wait a second or two longer after starting the car before you put it into reverse or drive? Also your not hearing the parking brake release are you?

Yeah, I know in my case as well that it abesolutely isn't the park brake. Not only am I always looking for the problem to happen, I even have double, tripple checked that the shift lever is fully in drive thinking it might not have been.

As far as waiting a few seconds before driving, I personally always and have my wife brainwashed to always let the car warm up for 20 seconds or when the RPMs drop.

[RobMunach]

Originally Posted by Pool Runner

Opps, yeah I realize there is no "pumping of oil" in any of the differentials. I guess I was thinking the center differential, the one that splits the torque or power from front to rear may have the clutch packs dry from sitting over night and that grunt and slipping feeling is the CVT trying to push the car against sticking clutch packs until the fluid lossens the clutch-packs. I really don't know what I'm saying as I really don't know as much as I wish I did about the AWD/ CVT in these cars.

My initial theory is that the fluid is not fully moving yet inside the CVT from sitting overnight cold or for a period of time. I asked my SA if they checked the factory fluid level and they said it was fine and in spec. I'm thinking I might change the fluid out on my own with a fully synthetic type.

No center diff in that car, only a clutch pack. Either way, a failure of that clutch would still leave you with front wheel drive - you would not feel any slippage.
Sounds like an issue with the forward/reverse clutch in the CVT.

[wxlidar]

Sounds like some of us are experiencing the exact same thing. It only happens when the car has been sitting a while (overnight in my case). Definitely not the brake.

To the posters that are experiencing this phenomenon, how does your CVT sound? Any excessive, in your opinion, noise like a whine or whistle? The reason I ask is I do have this excessive noise issue and one of the proposed culprits (by my local mechanic) is the CVT pump. If the pump is unable to provide enough pressure for the CVT rollers then the chain could slip.

Now, how do we get the Subaru to dig into this problem?

Thanks!