new owner: best preventative maintenance for 250k mi prius?

I'd get a nice K&N air filter, change out the PCV valve, and clean up the mass air flow sensor and throttle body.

Do the records show the last time the transaxle fluid was changed? That might be a priority. I recommend that you retain a sample of the transaxle oil and have it sent out for lab testing to determine the condition of the transaxle, especially if you don't know the last time the fluid was changed.

Lastly, the biggest piece of advice I have for you is to perform each one of these maintenance actions at at time, and then drive the car around for a little bit. Don't be like me and do everything in one go and then have weird stuff happen and wonder which maintenance action I might have botched that led to the weird stuff. Everything turned out okay but it's not worth the stress.

 

I'm not sure a K & N filter is necessary, you won't get any better performance....even if you remove the filter completely

 

Great ideas. I just bought a 2008 with 200k and have done the same things. Maybe some more experience people can give us some other tips. Here was the list of what I did:

Change Oil/Filter (5W-30 Castrol Edge High Mileage, Mobil1 Filter)
Transaxle fluid (OEM Toyota fluid)
Spark Plugs (Denso Iridium)
Change Intake Air/Cabin Air filters
Clean MAF sensor
Bore scope of cylinders to see condition (soon will make post of images for others to see)
Examine/clean throttle plate
Examine intake
Check AC high/low pressure (new gauge set to avoid contamination)

 

I use the K&N filter not so much for performance, but to not have to change the air filter as frequently and save money over the long run.

 

Good advice for a newer car but the OP has a 14 year old car with 250k so odds are the long run isn't going to be that long. Most folks don't understand how much cleaning and oiling it takes to keep those types of filter operating efficiently. Toyota air filters are about $18 on ebay; aftermarket versions even less.

+1 on all the items already mentioned to which I'd add look at those records to see when both coolant pumps (ICE and inverter) were changed and the belt. If it's been a while, it would be best to do those when you do the coolant flushes. You can also look underneath the ICE pump for colored evidence of coolant leakage.

Another possible failure point on gen 2 is wheel bearings.

Decide now if you want to start a fund for an expensive repair (inverter, electric brake pump, transaxle, head gasket) or ditch it. Also, keep a very close eye on oil usage. Finally, find a code reader solution (techstream, torque, etc) that's best for you.

GOOD LUCK!

 

I disagree with two out of three. K&N buys you nothing but headaches. Over oiling, under oiling, just don't go there.
Let me take time to endorse the PCV valve, unless it was done less than 100,000 miles ago.
'Cleaning' the MAF or throttle body may add problems you don't have now. Unless there are drivability issues, stuttering, stalling, racing, etc. let them be. If you MUST 'clean' your intake, buy a bottle of Techron every 100,000 miles and follow instructions.

Your Prius Maintenance Manual only goes to 120,000 miles so just assume it repeats. If the previous owner did the 120,000 steps at 240,000 miles, you can start at the 10,000 service. If they didn't, I would start at 120,000 service and then go from there.

If you can't see a drain and fill of the ATF in the last 90,000 miles, I would do one now.

There are Brake Fluid test strips to tell you if you want the dealer to flush the Brake fluid. (it is not a shade tree job in a Prius)

Here is the 2005 Manual:

https://www.toyota.com/t3Portal/document/omms-s/05ToyAllMS_MS0012/pdf/51w1smt.pdf

The Toyota Owners site can tell a lot of history if you have the VIN.
Toyota Owners Official Web Site

 

Brakes.

Nearly eight years, and 76K kms (admittedly not that much) our 2010 still has the original engine air filter, and it's barely darker than brand new.

 

check engine oil level often

 

I've never had an issue with K&N filters, if you follow the instructions there's not much that can go wrong with over/under oiling.

I'm curious, wat kind of problems can come from cleaning the MAF/throttle body? I meant both that AND the sensor, but if issues can come up from cleaning it I'd like to know before I do it on my next maintenance cycle.

Good point; however my K&N has been relatively maintenence free with the exception of the reoiling every 50k. I've done it about three or four times now with no issues.

 

I think one of the issues with cleaning the MAF is their sensitivity. They are very delicate parts that are measuring a critical thing that the computer uses for much of its calculations. From what I understand, they are very sensitive to any coating or debris on them. A lot of techs will say that you must use MAF cleaner (which you can buy at an auto store) to keep any contaminants off it. Some of the cheaper engine cleaners might have oils or leave residues, which can affect the calculations that the MAF makes. That's my impression.

In my limited experience, Carb cleaner has worked fine when I clean a MAF sensor. I check the ingredients (because they are not uniform) to make sure there's no oils in it, but I have not had a problem using that for spraying off a MAF sensor. If you're worried about it, use the special MAF cleaner.

 

Beyond the suggestions for added maintenance items listed above, I would also check the condition of the front struts and rear shocks and replace as needed.
Hints Regarding Replacement of 2G Front Struts | PriusChat
Replaced Rear Shocks | PriusChat

 

That's way too much for the transaxle fluid change, indicative of a service dept that's larcenous or stupid, or both. Somewhere between $75 and $100 is reasonable, and DIY is not hard, about $40 with new washers.

 

A more likely evaluation would be that oil was recently added to the engine. 10K mile oil change intervals for regular engine oil is excessive and this may have accelerated engine wear.