Powerboost Cavitating Noise on Cold Start

[Erikp16]

Glad I'm not the only one who has this issue... Guess it's what we get for getting a first-year model of something

I love the rest of the truck especially the generator when we go camping. I pull a small RPOD. It is able to run the AC on hot days if we camp unserviced. I am really hoping this year that they look into it.

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[Erikp16]

Hrm, sounds like the noise is being amplified by the exhaust, which means it's on the exhaust. Right where you put the camera under the truck is the location of the exhaust heat scavenging unit. That's a plate heat exchanger full of small passages. If I had to guess another possibility is if there's a portioning valve that meters the coolant flow. Cavitation possibilities increase if the line pressure is much lower than you'd expect it to be -- cold can do that, but it should be much lower than you'd expect to be present in a vehicle with hoses that are very flexible.

Did you check both coolant reservoirs?

ThanksI will check the reservoirs later. I’m sure it is good, but I’ll check.

 

[Porpoise Hork]

Sounds a lot like something rubbing. Does it ever go away when it warms up?

Also try starting it with the HVAC off so the ICE won't fire right up and see if it makes the noise with just the EV side powered. Then turn on the heat to get the ICE to fire up and listen for the noise.

 

[Snakebitten]

Right? That’s one problem is the moment they move the truck to the lift the noise is gone. The trucks needs to be parked outsid, sit outside overnight, and the temperature should be at least (-11C, 12.2F) somewhere in that range.

As HammaMan suggested, are both of your coolant reservoirs properly to the cold fill level?
I assume the cabin heat is on and the Powerboost is equipped with that crazy exhaust heat exchanger in order to heat coolant quickly during the ICE on-cycle for a coldstart.
There's a percentage of Powerboosts that came with leaky exhaust heat exchangers, although by now you would have known in yours was a "leaker".

 

[AndrewMC]

I love the rest of the truck especially the generator when we go camping. I pull a small RPOD. It is able to run the AC on hot days if we camp unserviced. I am really hoping this year that they look into it.

TBH I've said this to so many people if I custom ordered my PB I probably wouldn't have spung for the cost of that option, but it's turned into the most valuable thing on my truck. Really is such a great feature

 

[Snakebitten]

And here is the Powerboost Engine coolant loop.
(does not include the Hybrid High Voltage cooling loop)

 

[Erikp16]

Sounds a lot like something rubbing. Does it ever go away when it warms up?

Also try starting it with the HVAC off so the ICE won't fire right up and see if it makes the noise with just the EV side powered. Then turn on the heat to get the ICE to fire up and listen for the noise.

It does go away in about 10 minutes. Even if the HVAC is off it will start the ICE, the panel will show the reason is "Engine Cold".

 

[Erikp16]

As HammaMan suggested, are both of your coolant reservoirs properly to the cold fill level?
I assume the cabin heat is on and the Powerboost is equipped with that crazy exhaust heat exchanger in order to heat coolant quickly during the ICE on-cycle for a coldstart.
There's a percentage of Powerboosts that came with leaky exhaust heat exchangers, although by now you would have known in yours was a "leaker".

How do you know if you have a "leaky" Heat Exchanger? Something actually leaks to the ground?

 

[Porpoise Hork]

From what I understand about it in some cases it would, but also having low coolant in the reservoir is the most common symptom.

Since it stops after about 10 minutes, maybe monitor the actual coolant temp using a OBD11 dongle and app like CarTest (iOS) or Torque (android) to see. If it stops making the noise at the same temp then it might be related with the heat exchanger.

 

[Gros Ventre]

I've had that. The procedure for checking the transmission level is complicated. The fix for this is to have your dealer top up the transmission. They need to be very tight on this procedure as it's easy for them to call it full when it's still down a quart or so. One dealer said that it takes two people to do the level check: one in the drivers seat and one underneath at the transmission. Been round and round on this. In effect I had to train my dealer's mechanics on it.

 

[Gros Ventre]

Some further info on my experience. My past practice has been to change out transmission fluid in order to get manufacturing dust and such out of the transmission. So I've done that with this one, hence my experience with the fluid levels. Turns out that Ford in setting up the assembly plant for this transmission went to great lengths to have a clean plant. See this article from Car & Driver: https://www.caranddriver.com/features/g15377492/ford-10-speed-automatic-transmission/?slide=9 Had I known this I'd have done the transmission fluid changeouts differently. But at the end of the day I learned about fluid levels. I finally had to have my dealer measure how much fluid was drained on a fluid change so that they put that amount back in. Turns out its about 7 1/2 qts...

 

[Snakebitten]

I am personally convinced that the fluid level IS behind a lot of symptoms and complaints on these 10r80 transmissions.
And it's not an easy task to address for the average truck owner because it requires a thoroughly warmed up transmission, which on these trucks can take a lengthy amount of time. In some instances it's very difficult to get the transmission up to 205-215F.
And then when it IS at that temperature, it's a nasty situation to get to the dipstick, as well as properly top it off.

Man I miss the old school under the hood dipstick and fill tube.

 

[Porpoise Hork]

I am personally convinced that the fluid level IS behind a lot of symptoms and complaints on these 10r80 transmissions.
And it's not an easy task to address for the average truck owner because it requires a thoroughly warmed up transmission, which on these trucks can take a lengthy amount of time. In some instances it's very difficult to get the transmission up to 205-215F.
And then when it IS at that temperature, it's a nasty situation to get to the dipstick, as well as properly top it off.

Man I miss the old school under the hood dipstick and fill tube.

The fluid level was a factor with issues on my 20 Ranger being it was about 2 qts low from the factory. When I take the PB in to get the alignment checked next week, I'll probably have them check the trans fluid level as well to see if Ford finally figured out how much fluid to put in it from the get go.

 

[Gros Ventre]

I am personally convinced that the fluid level IS behind a lot of symptoms and complaints on these 10r80 transmissions.
And it's not an easy task to address for the average truck owner because it requires a thoroughly warmed up transmission, which on these trucks can take a lengthy amount of time. In some instances it's very difficult to get the transmission up to 205-215F.
And then when it IS at that temperature, it's a nasty situation to get to the dipstick, as well as properly top it off.

Man I miss the old school under the hood dipstick and fill tube.

You got that right!

 

[1985ns]

Hey guys

I posted a video of that same sound last winter. All I could get out of the dealer is “ford is working on it”. That was 8 months ago. I fully agree it seems like a pump struggling which makes me think It’s for the coolant lines that draw heat from the exhaust and go around the battery (to warm it). Explains why it goes away as soon as it warms up and why it only does it extreme cold as the coolant becomes Thicker.
My question is why wouldn’t they have caught this In cold weather testing. To my knowledge all vehicles go through the freezer test where they shove them in a freezer for hours then fire them up and beat on them. I know GM has a facility in Canada where they do that.

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