Random high revving

[1Guy1Truck]

My Maverick is no stranger to issues and a new one surfaced today. I was backing out of my driveway and right before I was going to put it into drive it started to rev like I was in neutral and slamming on the gas. However I was in reverse and my foot was on the brake pedal. I have a hybrid so I don’t know how high the rpms got but I’m sure it was very high. It stopped when I put it into drive. Anyone have an idea?
This is getting awfully frustrating, especially when I’m driving on a bad, backordered cv axle as well.

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[icegradner]

My Maverick is no stranger to issues and a new one surfaced today. I was backing out of my driveway and right before I was going to put it into drive it started to rev like I was in neutral and slamming on the gas. However I was in reverse and my foot was on the brake pedal. I have a hybrid so I don’t know how high the rpms got but I’m sure it was very high. It stopped when I put it into drive. Anyone have an idea?
This is getting awfully frustrating, especially when I’m driving on a bad, backordered cv axle as well.

This is a normal thing the system does when the hybrid battery has a low charge. Nothing to worry about.

 

[1Guy1Truck]

This is a normal thing the system does when the hybrid battery has a low charge. Nothing to worry about.

Interesting, seemed quite aggressive, definitely redlining I would assume. Thank you!

 

[icegradner]

Interesting, seemed quite aggressive, definitely redlining I would assume. Thank you!

Yeah, my previous Toyota hybrid did the same thing, and so does my Maverick. It is a little jarring, but it does happen from time to time.

 

[Larrythelunatic]

I was under the impression that “reverse” only works electrically.
If the ICE was operating, it was only to charge the battery, or to help provide heat.
So my question is……..
Was the high-revving ICE trying to move the truck, requiring unusual brake pedal pressure on your part?

 

[1Guy1Truck]

I was under the impression that “reverse” only works electrically.
If the ICE was operating, it was only to charge the battery, or to help provide heat.
So my question is……..
Was the high-revving ICE trying to move the truck, requiring unusual brake pedal pressure on your part?

Good question, my foot was on the brake when it started , I was afraid to remove my foot lol

 

[Glen Baker LLC]

Momentary high revving happened to me once, when I shifted out of reverse. I thought the side my big foot was hitting the gas pedal.

 

[710-oil-614]

I think it is electric motor only for reverse so if maybe your battery charge was too low, too cold, or a combination of both the ICE engine was trying to really over compensate in order to reverse the vehicle?

When you put in drive did the ICE engine shut off or RPMs just fall back down to normal?

 

[1Guy1Truck]

I think it is electric motor only for reverse so if maybe your battery charge was too low, too cold, or a combination of both the ICE engine was trying to really over compensate in order to reverse the vehicle?

When you put in drive did the ICE engine shut off or RPMs just fall back down to normal?

Yes and yes

 

[Ozarkbeard]

The ICE was just charging the HV battery, which apparently was low. That, or OP had the heater cranked. This will also make the ICE come on, to produce waste heat for the heater core.

The ICE cannot be used to back up the Hybrid, because there is no Reverse gear for it to use. To go backward, the electric engine just reverses direction.

 

[commadorebob]

FWIW, I have found my truck loves engine braking and will stay in a lower gear a lot longer than I would prefer. Especially when I pull into my neighborhood and am rolling down the hill towards my house.

Probably not related to this but it is something I noticed.

 

[HeyBales]

Lot's of great ideas for reasons why.

But the almost redlining sounds different.

Idle to be warm is about 1500-1700 RPM, idle to recharge battery about 2500 RPM.
Neither sound like redlining.
Unless it just sounded unusually loud that morning/location.

Now perhaps you were really racing in reverse with battery at 30% and engine needed to come on to recharge and a little higher RPM to provide some juice to the motor - but since you were braking not exactly using the motor a lot.

 

[1Guy1Truck]

Lot's of great ideas for reasons why.

But the almost redlining sounds different.

Idle to be warm is about 1500-1700 RPM, idle to recharge battery about 2500 RPM.
Neither sound like redlining.
Unless it just sounded unusually loud that morning/location.

Now perhaps you were really racing in reverse with battery at 30% and engine needed to come on to recharge and a little higher RPM to provide some juice to the motor - but since you were braking not exactly using the motor a lot.

Yeah this was not just normal high rpm. This was legit redlining. I’ll add it to the list to look at whenever my new cv axles arrive.

 

[Ozarkbeard]

"FWIW, I have found my truck loves engine braking and will stay in a lower gear a lot longer than I would prefer. Especially when I pull into my neighborhood and am rolling down the hill towards my house.

Probably not related to this but it is something I noticed."

With the Hybrid, more likely scenarios: OP's HV battery is low, or OP started the truck with the heat on. Either case may startup the ICE. I've had it startup in both situations, independently. And it can be loud.

 

[MakinDoForNow]

Yeah this was not just normal high rpm. This was legit redlining. I’ll add it to the list to look at whenever my new cv axles arrive.

Consider if ice is charging HVB and charging 12v and running the electric heat pot for the AC,plus Ford knows what else when you put selector in reverse the small generator may need to run at max. Also if the AC is in cool mode the electrical compressor may also be running really loud adding to the noise level. Next time it does it just turn AC off and see how much the noise reduces.

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