120,000 mile service and maintenance questions

Greetings,

I hope you all had an enjoyable Memorial Day weekend. I am coming up on 120k miles before the end of the year (put 7,500 on my used Prius in the first 5 months, and we are hardly into the summer where travel, day trips, and graduations/weddings/parties mean even more use of the car).

I know many of you would say "follow the maintenance schedule," but I have a few nagging things that might need more immediate attention:

1. Clanging/banging noise from the front end when I turn when stopped. It's sounding like struts or strut mounts, but it doesn't do it when in motion (or as loudly), so I was just thinking of DIY replacing the entire front struts with KYBs, unless it's a bad idea to just throw parts at it (car has almost 110k miles, even if it doesn't fix the issue, I'd say it might be worth it?) Any ideas what else could cause this?

2. Brake pedal cover worn out. I think I can easily DIY replace this myself, considering some options that may be a little less slippery since I do drive this car in the winter.

3. Some trim pieces are coming apart, causing water to enter my driver's side door. I think this is part of the reason for #4, which I'd like to do immediately.

4. I can barely hear a phone call on Bluetooth, and all the low-mid frequencies are distorted. I know I have a bad driver side speaker, but would assume the tweeters on the dash and the right speaker could still carry the rest of the frequencies for a semi-clear conversation. Would like to replace with these woofers (for a more hi-fi sound), any issues with them not being a "direct fit"? The impedance, size, and wattage should be close to the OE speakers and not cause problems: C 165 - Hertz car audio systems | The Sound Experience

5. Car started doing "HV Battery low" warning on extremely hot days when parked outside. I'm thinking I have a bad 12V, but if (at 107,000 miles and 9.5 years) the HV battery is going dead, what are my options? Used pack? Greentec? Had a really bad experience with a reman HV battery ($10+k) on my GM hybrid, the OEM battery had much better cell balance and reliability.

6. My entire dash rattles when the ICE starts up, I feel like I have a rough-running ICE compared to other HV and PHEV vehicles I've driven. Motor mounts? Spark plugs? As far as I know, all of those are original.

7. Maintenance. I want to go through everything myself (coolant flush, trans fluid exchange, plugs, inverter coolant, etc.) but am afraid I will cause more problems (especially after I had an inverter warning code post inverter coolant flush on my 2012 Volt). What fluids and items can I reasonably DIY without wrecking the car? I hate putting in the effort on a used car just to be told by a trans shop, "you should've left it alone". Are there any filters I should easily do? AFAIK, most of those are likely original on my car (same for the 12V battery, it has a 2017 date code).

Thank you for reading this long-winded post; #1, #2, and #5 are giving me some fear since I drive this car 2 hours daily, but #3, #4, and #7 are things I would like to tackle first - since I plan to DIY most or all of the repairs (going to a shop these days is just too expensive!) to improve my car's reliability.

FWIW - my skill level is: Have done major suspension work (ball joints, control arms) and drivetrain work (CV joints), but am afraid of internal component rebuilding (transmission, engine, etc.) including things like replacing timing chains and torque converters. I can turn a wrench but am not a pro.

 

Good point, I didn’t even think about that. Coming from growing up driving manuals, I always sit in a car (when pulled over to write a text message, for example) with the parking brake on and gear in Neutral.

Come to think of it, I don’t think I’ve ever sat with my Prius in Park, except when starting the car up (mine defaults to Park even if you shut it off in Neutral).

I’ll try to remember to shift to Park before sitting for too long as it appears to drain the HV battery.

 

I do make a habit of turning the car off, except when it's below freezing or extremely hot (90+ with a heat index close to 100) outside. Mostly because of medical conditions, but also for safety. If there is shade (such as at a bank with drive-thru window only), I'll turn off the car since the building blocks the heat. Otherwise, I do agree - it's simply wasting energy.

Never thought about this but perhaps it's to completely de-couple the engine. I don't know if we have clutch packs in our eCVT to truly de-couple the engine, but it would make sense (similar to many Jeep transfer cases where "N" is truly Neutral).

Now for the Repairs List:
Thank you all for the great suggestions, I'm glad to have knocked #5 off the list without doing any repairs. For #2, I installed a "classic car-style" brake pedal cover which looks like the Cadillacs of the 1960's and matches the American cars / hot rods I'm used to. It's an anti-slip material and feels similar to the stock GM clutch and brake pedals found on C5 and C6 Vettes.



For #4, I took a chance and ordered the following speakers off Crutchfield, should be here this weekend, and I look forward to taking off the door panels to find out what's the cause of my issue. I'm really hoping for just a corroded/rotted out door speaker, as I do not have distortion if I fade the speakers all the way back or all the way to the right... indicating a bad speaker (hopefully).



Does anybody know if on the base Prius Prime (non-JBL), if the door speaker is unplugged would that affect the tweeter in the dash? As in, are they wired in parallel? Reason being, my dash speaker still works, so if the door speaker got corroded and shorted out, I'd expect the amp or head unit to mute that channel. But perhaps it's just a torn-up cone or a rotted woofer surround that's my issue. Will find out soon!

#7 I am doing some research on, trying to find the best fluids and filters for my car. Not a shill for Amsoil (I don't think it's all that, previous oil analyses on 4-cylinder cars showed similar UOA results as Mobil 1 after 7,500 miles). However, if it can help extend the oil change to a 15,000 mile interval (vs Toyota's 10,000 recommended), I'm all ears. My commute is 100% highway and 45-50 miles one way, so I'd hope I can use a long-life oil and transmission fluid to avoid having to jack up the car frequently.

Feature Request List:
And I guess I'll add one more, #8: I recently signed up for ChargeSmart (EV charging program through my utility) where the rates are best from 11pm to 7am which is great - I leave before 7am every morning and don't get home until late in the evenings. However, sometimes I'll get home at 8pm, charge for an hour, and have to run an errand between 8-9pm.

Is there a way to program logic into the car where it charges from 7-11pm just partially (say, 6 miles) and then resumes charging from 11pm onward? That way, it ensures enough EV range + does not require any driver input upon my return (besides plugging back in).

Below is a snippet from my utility's ChargeSmart program, which I just signed up for today, and pending approval should be active in June.



Thanks everyone for the help, I will update this thread as I move along with the DIY repairs.