The engine light went on and I took it to my mechanics who is good on everything except Hybrid system. I took some photos when he looking at the code. He wants me to leave the car during weekdays, so he can do detailed check, and call dealer for help if need to. Just looking at the codes, he has no idea what's gone wrong so far. Immediate after the lights on, I filled gas and the mpg dropped to 31, soon back to 37 on a hot day 85 degree. At red light, I feel the engine still running, not very smoothly. But the next day, it back to normal, mpg also back to 48 something. My friend has a 2005 with 140K also got the same code. His mpg dropped to 40 and feel that engine power is lower now. I would like to know if this is a common problem, what's the most probable cause, and if there are many possibilities, what's the best way to approach (change this cheap parts first, see if it solve the problem...). Here is problem area by OBD-II: Engine and ECT Hybrid Control ABS/VSC/TRC Air Conditioner Immobiliser At one time I completely ran out of gas and the battery was at the last two bars when I glide into gas station Some messages may caused by this.
DTC P0505 points to a problem with the idle air control system. The actual idle speed has significant variation compared to the engine ECU's targeted idle speed. Potential problem areas include: - throttle motor shaft is binding - a leak in the air induction system allowing unmetered air to enter - a loose PCV valve allowing unmetered air to enter - a failed engine ECU (aka ECM) Try cleaning the throttle body interior and throttle plate first (using the minimum amount of throttle body cleaner) and look for air intake leaks such as a bad engine oil cap O-ring, missing oil dipstick, loose PCV hoses. If the above doesn't help, then the throttle assembly including the throttle motor may need to be replaced.
Thank you Patrick! I just went to check the dipstick and engine oil cap seal. They look OK. I replaced PCV Valve 3 weeks ago, and mentioned to mechanics that connection air leak maybe a cause. He said if that's the case, engine light should be on right after PCV change. Also, it seems the oil leaking/burning is getting much worse. Three weeks before the engine light on, I had to add 1qt/500 miles. Does this has anything to do with P0505?
That might be causing your spark plugs to get gunked up, so yes this could cause the engine to run rough. Definitely take a look at the plugs and clean if necessary. BTW. What oil (brand/type/grade) are you using?
I don't believe spark plug is the problem, which was replaced 60K miles ago. I used generic synthetic oil, as well as regular oil such as Pennzoil, mobile. Oil consumption is the major maintenance cost for me now.
1 qt in 500 miles in a Prius corresponds to about 1 part oil to 40 parts gasoline, man you're basically a two stroke lawnmower at this stage. You can gunk up those plugs in under 10k miles under those conditions. Time to either try something drastic with the oil or get a new engine. If I was you I would have been experimenting with 10w40 or even 15w50/20w50 over the summer. I know in winter it's going to be hard for you to go too far with oil grades, but short of a new engine there's not much to lose in trying. If I was you I'd be using a HD dino oil of the highest grade you can get away with at your given temperature. There's plenty of choice in of good quality heavy duty dino oils at relatively low cost. Over at bobistheoilguy there's a gen2 owner (from Va) who has been running 15W40 (Rotella T) without any problems throughout summer.
I did not know burning oil will result in bad plug. Will try some new oil next time, and gets the plug checked now. Thank you!
Yeah, it mightn't be the problem, but it's definitely worth a look at the plugs. When you add oil to fuel for a 2 stroke engine (like a lawnmower or outboard for example) then you typically use ratios from about 1:25 down to about 1:100, depending on the particular application. But that 2stoke oil is designed to burn fairly cleanly, with as little plug deposits as possible. You're essentially burning regular motor oil at about 1:40, so it definitely could be accelerating the rate of spark plug deposits.
The combination of a Idle air code, a recent increase in oil consumption and a newly replaced PCV valve strongly point to an issue with the PCV valve or hose connections.
Hi Allen. The PCV valve must be able regulate the amount of air that is diverted though the crankcase. In particular, it is very important that it restricts the flow when the intake vacuum is very high, such as idle and light engine load. If the PCV valve fails stuck-open then way too much air can be passed from the crankcase to the engine intake. This has two effects (both of which you appear to be seeing). 1. It can upset the idle fuel air mixture (by injecting excess air downstream of the throttle body), causing rough idle. 2. When too much crankcase air is being drawn, instead of only scavenging the nasty crankcase vapors (blow-by combustion products and steam) as per design, it also start sucking out fine oil mist that should be staying in the engine. This of course increase oil consumption.
Hi there, I too have kind of high oil consumption but the book says 1 quart between oil changes so I wasn't worrying as I change my oil every 3-4 k miles and am using a quart (or more) and now too am having some rough idling at times (first start up in am more so then goes away) ALSO have the original plugs still in at 140K miles BUT this car has always used a quart or more between oil changes(every 3-4k mikes) I'm looking for info/video on changing spark plugs on Gen 2 (2006)
OK, I replaced PCV and its hose with Toyota parts. I started to use 20W50 engine oil (thick like melted butter) a month ago. Now the engine warning light is gone somehow, but oil burning is still at 1qt/500 miles level. I checked the spark plug. It has grease on it. MPG drop to 43 ~ 47. I wonder if the situation will getting worse. If so, what's the cost of replacing a used engine, or fix it. The mileage is 198K now. Started burning oil at 150K. Where to find a used engine in Chicago area? What's the labor cost to install? And are there anything special about Prius engine installation (anything to do with hybrid system)? Thanks!
Wow 20W50 is pretty extreme for Chicago. If that's not slowing it down then it looks like trying to do anything with viscosity is going to be pretty pointless. Good for an experiment , but probably best now to get that stuff out of there before winter really hits. It certainly seems like your engine has had it's day. One last thing that could be worth trying is Valvoline Maxlife (stay with 5W30 for winter). It has seal conditioners/swellers that might help (not straight away but over the course of a few oil changes). If heard several good reports of this oil having a positive effect on oil consumption. BTW. If you try it then just get either the conventional (red bottle) or the nextgen (green bottle), it's not worth spending extra on full synthetic with your consumption rate.
Never forget to check the obvious! And thank you Patrick Wong for your post on the DTC PO505 code. Turns out we had no motor oil cap! Here's the story in case it may help someone else: Husband changed oil in July. I started smelling something like gas and exhaust. He didn't smell anything. Summer months passed. Kept the windows open. Prius 2005 ran fine, in fact saw a slight uptick in mileage. Fall arrives and the windows are rolled up... and I'm in the back seat gagging. Husband takes trip out of town. I took Prius to O'Reilly who have a Bosch fancy code reader. Says PO505. Got home and checked this thread. Opened hood and lo and behold, no engine oil cap. Oil sprayed all over the place but not enough loss to trip a warning light. Moral of the story? Thank you Prius Chat, Patrick Wong -- and start with the obvious!
