My 2006 Prius has 208,000 miles. I love the car. However, there are some events occuring that make me feel uneasy as I do not know what they mean. Roughly a year ago my mpg began declining from a long time average of 46. it dropped slowly until i was struggling at 39 to 41 mpg. I changed the plugs (badly needed) and air filters and the mpg did slightly improve to 43 mpg and remained at that level. Prior to the year, I could get 50 MPG if I drove appropriately and could average 46 without any effort. for years. I also noticed about a year ago a whirring noise that appeared to be coming from the firewall near the driver after I turned the car off. It could last long enough for me to actually get out of the car and take a stride or two betfore it turned off. I also thought the exhaust sounded a bit loud near the driver seat. About half as loud as any normal car which had holes in its exhaust. About 4 weeks ago, on a whim, I had autozone check the DTC codes. They captured a P0700 error. a few days later, the car stopped on the way home. would not go into any gear but neutral. engine never turned on. The big triangle turned on with all the other lights. A neighbor checked DTC codes with a universal reader. He got a P0420. Later I hooked up Techstream with a VXDiag Nano attached by USB. I cleared the DTC codes and charged the 12 v battery which definitely needed charging. when i checked for codes i got a P0420. with NO P0700. I cleared all codes and ran the car for about 15 highway and mountain road miles. Somewhere in there I got a check engine light and when I got home looked for DTC codes. Only the P0420 code was revealed. I cleared the code and ran it for another 20 highway miles and got no DTC codes and no check engine light. However when I checked the emissions I found the Evaporative System was "incomplete" and yet it was in the "pass" state. So I am getting a bit nervous. Part of me is voting for a "new" second hand car. But my finances suggest , while I can afford it, I am removing any margin for unexpected health or home or car expenses. So if I hang in there with my 2006 I might be able to extend its life but maybe I am putting my wife in a precarius place. I am 73 and may drop dead (I do have cancer but it is in remission). Consequently I am considering purchasing a 2014 Prius Plugin for $14,499 owned by a 57 old guy who had it serviced routinely (receipts) and used it to commute at moderate speeds. it has 61,000 miles. I am thinking of purchasing it from this guy. The selling points I appreciate are that the battery technology is lithium ion and has a 4 kw capacity. I am assuming that Lithium ion batteries will last longer than the metal hydride batteries in my 2006 Prius .. I am also assuming the greater capacity means that the batteries are under less stress in normal operation (not in the plugin mode which I am not using) than fewer batteries with only a 1.x kw capacity. Any advice? maybe I am just letting a few DTC get to me and hence am blowing the issue way out of proportion. i do enjoy troubleshooting. I am not a mechanic but have fixed all my cars over the past 50 years. For the most part, guys like you have hand held me to the point I have been able to fix just about all my car problems. I look forward to hearing from you.
The whirring noise is most likely a “coolant control valve”. Should not be very expensive to fix. Same thing happened to mine, I actually purchase the valve and just waiting for a good day to replace it. The mpg decline happened to me as well, most likely from the hybrid battery getting weaker. Even with the MPG’s in the low 40s, still better than most new cars Good luck iPhone ?
You only live once, you don't get a second chance. If I could, I would die with tons of debt and lots of toys
When to abandon your Prius?! Only when its almost dying, or dead! Lots of issues you got with that Prius. Sell em, and get another one.
Thank you so much for replying. It feels good to know other people experience similar symptoms and know what might be done to fix them. Not sure I understand "iphone?" yes I have one....not sure if i sent the message via it or my old old laptop
tough choice. the plug in battery isn't going to help in longevity or anything else for that matter. keep in mind you don't get a spare tire. maybe you could find a decent corolla or something for 10k and keep 5 in the bank. how many miles a year do you drive?
When the 12v is dieing it does all kind of crazy things. Mine threw the triangle, codes, acting crazy, and died on the size of the interstate....all that happened was I’d just had a new 12v installed and the terminal was a little loose. Tightened it up and it was good to go. I might be tempted to replace the 12v battery and the coolant control valve and see how it’s going after that. Also, when your mpg fell, had you replaced the tires? I’ve been reading lately about how choosing a tire that isn’t designed to have real low rolling resistance can hit the mpg very hard. Some people lost as much as 10mpg from a poor tire selection.
How can you conclude the battery was dying and "does all kind of crazy things", when clearly the loose connection was your problem? Simply fixed by tying up the loose connection! I don't see how your data point is even useful.
Probably didn’t word it quite right....it did the same thing when the battery was dying. Then once replaced it seemed fine at first then the terminal got loose after a couple days and it started acting crazy again....I thought the new battery was defective but realized it was loose, tightened it up and it’s been fine every since. Either way, clearly the data point would be relevant because a loose connection causes voltage/amp drop, as does a bad battery. In either case the data point would be applicable because the issue is lack of strong 12v power. Since his 12v is weak then this could be causing him issues that don’t seem relevant yet are. Rather than just charging it, I’d go ahead and replace it...but that’s just me. I’ve never had good luck with a 12v being strong once it’s died and been recharged.
I don't know. Usually when people post a "Should I do This" thread, they will give you some clear cut clues as to what they REALLY want to do. But I can't really get a line here. Both moves have their supportable validity and their risks. I would say assuming this is the original Hybrid Battery from 2006, it is then likely that it is heading towards replacement. This is a tough answer to give. So I'm just going with my gut instinct. Which is, IF you can afford it? Upgrade. 12 years and 206,000 miles is a good run with a vehicle, period. At the very least I speculate you're coming up on Hybrid Battery replacement being necessary. Not to mention the entire vehicle has over 200,000 miles on it and 12 years of operation. But there really is no wrong answer here. If you are uncomfortable making the investment into a "newer Prius"? Then don't do it. $14,500? The cost of the newer Prius you are looking at... Well my guess is that for far, far less than that, one could have the 2006 checked out, and fixed up to a reliable standard. I'm coping out, but it really is up to you. Upgrading has it's obvious cost and potential advantages. And staying the course, comes with it's potential costs and advantages. My 'personal" gut instinct is if I was in that situation and felt I could comfortably and happily upgrade? I'd upgrade.
Lower mileage years before failure is my current theme: Bad Hybrid Battery & Mileage Chart | PriusChat
Any car can break down, if it's mission critical to have a car always working, then maybe considering owning 2 cars.
If you need the car every day and don't have a second one maybe it is time to get one that is newer and with lower miles and if a Prius one with some warranty left on the battery. Having a spare car does remove some of the worry about getting to work.
