Plug-in Hybrid

[EvenSteven]

I currently have a regular hybrid car, and with a newish shorter commute, have been having trouble with the engine getting a milk shake consistency build up from never getting the engine up to temperature to burn off water vapor.

I am considering getting a plug in hybrid where the ~30 mile all electric mode will cover 90%+ of my driving. Will I still have the problem of water build up?

[Bartlebooth]

Water build up where?

[EvenSteven]

Water build up where?

I don't know exactly, but it is covering and gunking up the cam shaft sensors.

[RWD]

Condensation can build up in the engine oil which reduces its performance and causes accelerated wear on the engine. This is assuming your actual problem is condensation and not a bad head gasket (coolant mixing with oil). If the problem is too-short of drives a plug-in hybrid where you almost never turn on the engine is unlikely to help (condensation will build up even while the vehicle is sitting unused). A full EV would fix the issue permanently, of course.

Some mitigations you could consider:
- Go on a longish drive at least once per month. You just need to get the engine oil temp above the boiling point for water. A half hour on the highway should do it.
- Change the oil more often. You can send oil samples to a lab to see the wear your engine is experiencing and whether you should adjust your oil change interval.
- Use synthetic oil if you aren't already. It is more resistant to forming water droplets and won't break down into sludge easily.
- Use an additive designed to prevent condensation

[Miss Piggy]

I've been driving a plug-in hybrid for nearly 10 years, and I've never seen anything like what you're describing. Then again, I kind of have no idea what you're describing.

Mustachian to Mustachian, I feel compelled to tell you (and take this with a grain of salt because my car is nearly 10 years old, so they're likely made differently now) that the plug-in battery will degrade. I used to get about 30 miles per plug-in before it switched to hybrid mode. Now I get 20 (or fewer in the winter) miles on a charge.

[EvenSteven]

I've been driving a plug-in hybrid for nearly 10 years, and I've never seen anything like what you're describing. Then again, I kind of have no idea what you're describing.

Mustachian to Mustachian, I feel compelled to tell you (and take this with a grain of salt because my car is nearly 10 years old, so they're likely made differently now) that the plug-in battery will degrade. I used to get about 30 miles per plug-in before it switched to hybrid mode. Now I get 20 (or fewer in the winter) miles on a charge.

I bike to work, but use the car to drop the kiddos off at daycare and trips to the grocery store and Costco. Daycare is about 1.3 miles away, and costco is about 3.5 miles away. So i drive probably 2.5 miles per week day, and maybe 10 miles on the weekends. I was hoping to avoid the need to drive aimlessly on the freeway just for car maintenance purposes, but maybe I can come up with something to have it be somewhat purposeful.

[ChpBstrd]

I'm not sure we can 100% rule out the possibility of a coolant leak, due to a head gasket or something else.

Change the oil and filter. Then go on a road trip, getting the engine nice and warm for a period of time. Then check to see if the oil has a milkiness to it.

If no: I think you need a new PCV valve. This is a cheap maintenance item that nobody ever maintains. It helps the engine breath out the gases that blow past the rings, including water vapor, and seals up the crankcase when the engine is not running. A working PCV valve is also critical to your engine's longevity.

If yes: Probably we're talking about a coolant leak. Run the car through a dealer auction. They deserve it.

[ChickenStash]

Enough condensation to turn the oil milky seems like a stretch but stranger things have happened. Is the coolant level low or dropped from normal? If there is any doubt, I'd suggest getting an oil test done to make sure. I've used the Blackstone Labs folks linked above with success.

I might have overlooked the model and year but if it's a 2010-2015 Prius, they have a higher than usual (for a Toyota) failure rate for head gaskets so that's something to look out for.

[EvenSteven]

It’s a 2013 Ford Fusion. And the coolant was low, not empty, but low.

[RWD]

You should absolutely figure out if the head gasket has gone. There are several ways to test. Compression test. Or pressure test coolant system. Or a kit to test for exhaust gases in the coolant system. Or send in an oil sample.

[EvenSteven]

Thanks for help everyone, I’ll try and report back with results

[GreenQueen]

We have a plug-in hybrid in a cold winter climate. No issues like you are seeing with your hybrid. We almost never use gas as our driving radius is covered by the electric range (about 30 miles). So that is fantastic. We got a good rebate on an at-home charging station, because charging with a 110 cable is slow (think 8 hours). This isn't an issue if you don't do many trips in a days.

If you live in a place with true winter, short trips will run on gas in the winter - we use as much gas to go 1 mile to daycare every morning as we use to go across town. So not a major thing, but it surprised us. We don't see an issue with range dropping in the winter, but friends with full electric definitely do.

[jeninco]

We have a plug-in hybrid in a cold winter climate. No issues like you are seeing with your hybrid. We almost never use gas as our driving radius is covered by the electric range (about 30 miles). So that is fantastic. We got a good rebate on an at-home charging station, because charging with a 110 cable is slow (think 8 hours). This isn't an issue if you don't do many trips in a days.

If you live in a place with true winter, short trips will run on gas in the winter - we use as much gas to go 1 mile to daycare every morning as we use to go across town. So not a major thing, but it surprised us. We don't see an issue with range dropping in the winter, but friends with full electric definitely do.

We live in a slightly less cold place, and also really like our plug-in hybrid. (Well, we like the idea: the execution of this model -- a 2019ish Prius Prime -- leaves a bit to be desired, particularly with respect to having to use the oversized touchscreen to control almost everything. I think they changed it in the following year.)  The gas engine will turn on if it's sufficiently cold, but regularly old cold weather it often won't. Also, the defroster kinda sucks...

But, in general, for the kind of use you're discussing (multiple fairly short trips) it works well on electric, and for longer road trips, the 80ish MPG is pretty awesome!

[snic]

We have a plug-in hybrid in a cold winter climate. No issues like you are seeing with your hybrid. We almost never use gas as our driving radius is covered by the electric range (about 30 miles). So that is fantastic. We got a good rebate on an at-home charging station, because charging with a 110 cable is slow (think 8 hours). This isn't an issue if you don't do many trips in a days.

If you live in a place with true winter, short trips will run on gas in the winter - we use as much gas to go 1 mile to daycare every morning as we use to go across town. So not a major thing, but it surprised us. We don't see an issue with range dropping in the winter, but friends with full electric definitely do.

I guess if "true winter" means the weather is consistently below about 20 degrees, you'd do a lot of driving on gas. Anything above that and usually the engine doesn't kick in. (Based on driving a Chevy Volt and Rav4 Prime - for the Volt the threshold is actually 15 degrees.)