Hello everyone, I have an 06 Prius with 237k on it I replaced the hybrid battery with a refurbished one at 235k I commute to work about 720mi per week so it was about 3 weeks ago. Car was running great I always do the engine oil change every 5k with full synthetic. Last time I did it was 2 days ago but now the engine has a knocking like noise coming from the valve cover. 1 thing I didn't do this time was change the oil filter i couldn't find my filter socket and autoparts stores were closed I had already drained the oil and I needed the car for work the next day. Also the engine doesn't shut off how it usually does while running under 40 and feels like the engine keeps running constantly. You think by not changing the oil filter will cause all of this?
I think you are experiencing two separate issues that just happened around the same time. 1) The remanufactured battery is going out. Should begin to throw codes sooner or later. 2) Engine sound can be valves out of spec (more of a clatter) or bad connecting rod (knock). A good, experienced mechanic should be able diagnose it immediately by ear.
It could be since the hybrid battery is not providing any power its making the engine run much harder making it noisier.
also just to make you feel less worried about a engine internal failure. If your oil drain plug did not have metal shavings stuck to it then odds are you may have a misfire. Heres a link to a video if your car sounds like this you should take the car to get scanned for any codes. (Is the check engine light on?) Just about every prius engine ive had roll into the shop for a knock like noise it was because of a engine misfire. Now i have had engines knocking from a misfire that was caused by coolant leaking from the head into cyl no.3. Which turned out to be a bad head and gasket. But most strange knocking noises ive fixed generally was a failed or failing coil pack. Idk why or how a misfire causes a rod knock like sound but these little turds for some reason make you panic for nothing. If your coils are original to the car. Thats probably gonna be your issue. Video
Post back if that helps you solve your knock.. just remember these cars really like to make you panic. Also the engine is probably running more often to produce the power to still power mg2. If the engine is runningnon 3 clyinders it will cause 75% charging vs all 4 cylinders firing that charges at 100% power. So my educated guess will say that the engines running more to compensate for the misfire to keep charging levels at its happy points.
Meckkush--how often do you see bad coil packs, and is there a common mileage that this occurs? Would you recommend replacing these preemptively? I use mine frequently for long trips with my family and I like to minimize my risk for being stranded.
These engines are TOUGH, not changing the filter is unlikely to have caused this. When you say knocking, like very audible? If so, it is not misfire related, that's hardware making that noise. Lucious Garage has documented a number of failures that cause the knocking and poor performance similar to what you describe.
Why would shavings be stuck to the oil dump plug? It's not magnetized like the trans plug. So you really don't know what your talking about.
Not changing the filter didn't and won't do any harm, just change it next time. Is the check engine light on? If so, have you read the codes?
I had this exact experience at about 140K miles, caused by a bad coil pack. You can read the details of it HERE. Readers Digest version: replacing coil #1 fixed the problem... along with a lot of great help from folks on this forum.
