Impending transmission failure maybe

Dave Merrill

Dave Merrill

Axe-Master
A few days ago, I noticed my 2014 Prius c sounded like it was intermittently revving a bit higher than usual, then back to normal, no change in speed, like it was partly out of gear. A few minutes later, it gradually slowed to a stop, unable to move, engine still revving normally, like it was in neutral. I shut it off, back on, back to normal. I've driven it to various errands since, including up a big hill at highway speed, all normal.

I went to my local gas station/repair shop, asked whether that could be a symptom of low transmission fluid, they said maybe, asked if I'd checked it. I said I couldn't figure out HOW to check it, they couldn't either. Went to my closest Toyota dealer, they said there's no dipstick, it can only be checked electronically, by a dealer, which they couldn't do that day.

Is this a sign of upcoming transmission failure?
Should I take it back to Toyota for service?
What's the odds of it being a catastrophic failure that it doesn't make sense to spend what it'd cost to fix?
 
Pretty lame to not have a dip stick. I’d get an estimate and then decide what to do. Transmissions are pretty steep. Best luck Dave.
 
Sixstring said:
Did it throw any codes (Engine light)? Also found this article Engine Revving but no acceleration
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No dash lights.

Consensus on Prius Chat is that it's unlikely to be the transmission, even though that's what makes intuitive sense to old school car resuscitation wrangler me.

Given that this was a one-off, so far anyway, guess/hope is that it was a computer glitch. Here's a quote:

"The hybrid control unit has authority to do whatever it wants. Sometimes it wants to spin the engine (without burning fuel) to reduce the battery state-of-charge. That can be in response to high battery temperatures or other conditions.

The computer can do this whether the car is moving or not. It doesn't really announce what it is doing, so it can look like it is just revving on its own without driving.

Other times it may choose to run the engine to raise the battery state-of-charge. Again, it's just the computer responding to a long list of sensory input and trying to do things to maximize the hybrid battery lifetime."

So the recommendation is to wait and see what happens, get pro service if it comes back or manifests some other way.

Other thing is, they have zero respect for or trust in all Toyota dealers. They're apparently the best source for the big hybrid battery if I need one, which maybe might be what's behind this maybe, but for diagnostics etc, they're just focused on making money.

I found one non-dealer service place that advertises hybrid repairs, exactly one, not super handy to me, but I'll go there if it comes to that.

We'll see.

In better news, the CTEK battery maintainer I got works a treat, car just starts, almost like a real car. Ergonomics are solidly meh, best I've figured so far, but it'll work.

Bleh. More faffing around than I'm really up for with cars, but it's what we've got. And I'm glad we have it alrighty.
 
At 10 years old, it wouldn’t hurt to change the fluid, which would make certain it’s full. Even if you take it in for an engine oil change, they should check the other fluids as part of the service. It’s a win-win, other than the cost of an oil change these days, as fresh lubricants are always a good thing anyway. Look at the bright side, at least it’s not my 8-quart-holding Tundra!
 
Rick said:
At 10 years old, it wouldn’t hurt to change the fluid, which would make certain it’s full. Even if you take it in for an engine oil change, they should check the other fluids as part of the service. It’s a win-win, other than the cost of an oil change these days, as fresh lubricants are always a good thing anyway. Look at the bright side, at least it’s not my 8-quart-holding Tundra!
Click to expand...
It's still a Toyota! I have 237,000 on my 09 Taco and it's still go'n! A little paint, reupholster the front seats some fresh plastics and a few blingy items and I saved myself 40k!

65679399023__C9E435D0-D760-4C2A-9515-5717D3FBAEE9.jpg
 
Rick said:
At 10 years old, it wouldn’t hurt to change the fluid, which would make certain it’s full. Even if you take it in for an engine oil change, they should check the other fluids as part of the service. It’s a win-win, other than the cost of an oil change these days, as fresh lubricants are always a good thing anyway. Look at the bright side, at least it’s not my 8-quart-holding Tundra!
Click to expand...
We really don't drive much (which is the root of the battery semi-fail), and we have kept up with oil changes in general, so I'll check, but I don't think one is due. In any case, really doubt that has anything to do with the observed weirdness.
 
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Dave Merrill said:
No dash lights.

Consensus on Prius Chat is that it's unlikely to be the transmission, even though that's what makes intuitive sense to old school car resuscitation wrangler me.

Given that this was a one-off, so far anyway, guess/hope is that it was a computer glitch. Here's a quote:

"The hybrid control unit has authority to do whatever it wants. Sometimes it wants to spin the engine (without burning fuel) to reduce the battery state-of-charge. That can be in response to high battery temperatures or other conditions.

The computer can do this whether the car is moving or not. It doesn't really announce what it is doing, so it can look like it is just revving on its own without driving.

Other times it may choose to run the engine to raise the battery state-of-charge. Again, it's just the computer responding to a long list of sensory input and trying to do things to maximize the hybrid battery lifetime."

So the recommendation is to wait and see what happens, get pro service if it comes back or manifests some other way.

Other thing is, they have zero respect for or trust in all Toyota dealers. They're apparently the best source for the big hybrid battery if I need one, which maybe might be what's behind this maybe, but for diagnostics etc, they're just focused on making money.

I found one non-dealer service place that advertises hybrid repairs, exactly one, not super handy to me, but I'll go there if it comes to that.

We'll see.

In better news, the CTEK battery maintainer I got works a treat, car just starts, almost like a real car. Ergonomics are solidly meh, best I've figured so far, but it'll work.

Bleh. More faffing around than I'm really up for with cars, but it's what we've got. And I'm glad we have it alrighty.
Click to expand...
I don't know much about the Prius other than they are a tad pricey for what they are. I knew some that had one caused him a lot of trouble and that was enough for me to hear about it.

Vehicles in general today are pretty lame with respect to reliability, dealer will charge you an arm and a leg to do basic maintenance. I work on my rig and have done so pretty much from mile 0 and have saved thousands doing so.
 
A hybrid, who knows. Personally I’d start building a war chest for a transmission but thats me. Good luck. My Infiniti Q50 tranny went at 140k miles. Sealed, no way to check it. Not much warning. bucked like a pissed offf horse for a few miles then died.
 
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