Knocking Lack of power issue

Greetings, everyone. This is my first post but I have benefited tremendously from lurking in here in the past. I have read all the posts I could find that I think are relevant to this matter and I could use some help.

This is the noise heard with my GEN2 2006 Prius with 293K miles. As expected, it burns oil. I have had no issues at all with this car with the exception of needing to add the resistor to my dash and regular battery and tire replacements. I have no engine codes. However, I did pull a P0420 "catalyst" code before I began my troubleshooting. I cleared it and it has yet to reappear for 60 miles. I have now replaced the Spark plugs, Coil Packs, Fuel injectors, filled up with premium fuel with seafoam, and topped off the oil with Lucus oil treatment and it made no difference. I have since reinstalled my original OEM coil packs and fuel injectors. The noise sometimes goes in and out as I attempt to observe it but the noise is not limited to a cold start. I can hear it when driving around town but it is too faint to hear on the highway. It does seem to speed up with higher RPM. It is obviously present while idling and Driving but not in neutral or reverse. It goes away once the car begins to run on battery. This video was taken while it was in maintenance mode. I have attempted to listen with a mechanic's stethoscope but I could not tell where it was coming from. Other symptoms include an immediate loss of power in acceleration thus also creating low gas mileage. Loss of power can really be felt while going uphill on the interstate. I can get up to speed but it takes more power to get it there. I have let my oil run low in the past and it was 2.25 quarts low when the issue(s) started. I topped it off with Mobil 1 high mileage and then later siphoned out a quart to add the oil treatment but did not notice a difference. Other observations include coolant levels are stable, no white smoke coming from the tailpipe, and my oil is not milky. I do not mind getting my hands dirty to fix this. Any help would be appreciated. Thank you.

 

While I wait for my post to be approved, I just wanted to add that even though I have may eliminate several of the easy low-hanging fruit repairs, I still have an interest in knowing exactly what is wrong. That being said, anyone that is of the opinion that the engine is ruined, I would like to know specifically why you think that is the diagnosis and exactly what is wrong. Also, is it worth investigating the oil control valve filter? I have seen several people theorizing it would cause these issues but I have not seen anyone affirmatively say that it was the reason for their problems.

 

Thanks for the input. Can the specific issue be determined by the video sound and description? Also, does a noisy valve create a lack of power or am I looking at two separate issues?

thanks forthw

 

Thanks again for the replies. I understand that 293k miles is a lot of miles and the most effective thing to do "may be" to replace the engine. With that understanding, I am specifically looking for what is wrong with the engine based on the symptoms I am describing. This was not an issue of an engine wearing out over time but a problem that happened within a day. Knocking one day, when it was not the day before accompanied by immediate performance issues that were not present the previous day. I went on a 45-mile trip and the performance was cut in half by the end of the voyage. Also, I checked the hybrid battery life with Dr. Prius and I currently have 59% life left with everything testing fine, so I am good there. I have read several posts where someone has presented an issue and the advice was to replace the engine because it was old only to discover the problem was as simple as a plug or coil pack. Respectfully, if you are telling me I need to replace the engine because it sounds like I have attempted all of the known solutions available and further diagnosis is futile, I would be willing to accept it easier than the engine is simply worn out without me knowing exactly what the issue is.

1. Does the noise sound like a bucket valve issue or something else?
2. Would a noisy bucket valve cause immediate performance issues(MPG cut 50%)?
3. Could I be experiencing a "catalytic converter" issue due to the excisive burning of oil and the fact I had pulled the "cat" P0420 code?

Thanks all for the input. I am sure everyone understands why I would want to eliminate all minor issues before just replacing the engine simply because it is old. I learned to fix my MFD with a 50 cent resistor and my hybrid battery by replacing one cell for 60 bucks by reading posts provided by Priuschat members, so I have been positively conditioned to exhaust resources before giving up without knowing what the issue is.

 

Thanks again for the replies. I understand that the lack of responses in this post may be due to the lack of my realistically available options for the issue. I am willing to relegate this Prius to only driving around town and eliminate any long trips due to the existing noise. I understand that an engine with 293k miles that knocks and burns oil is on its last leg. I am not solely depending on the car and my current desire is to get every mile possible out of it before it will no longer run and I am required to scrap it.

My problem is that I still do not understand specifically what I am dealing with. What component is actually causing the noise? If it is a noisy rod or valve, would a thicker oil or specific oil brand help lubricate the problem component enough for me to get an extra 10K miles out of it? Does a loose or noisy value or rocker cause immediate loss of power? Could the sudden loss of power be due to a stopped up catalytic convertor having to deal with all of the burned oil? Is there anything else worth checking such as the VTT oil control valve before I give up?

I appreciate your help. Even if I am unable to solve the issue I hope to be able to at least earn from it myself or create a chronicle that could help others with the same problem that stumble across this post.

 

This is some good information. I will need to do some research on learning about a damper failing. I assume if a piston skirt is broken, it can be verified by finding it in pieces at the bottom of my oil pan. Please correct me if I am wrong. '"JC91006" is right that I do not want to throw money at a sinking ship. What will be the eventual outcome of not doing anything and driving the car 5 to 10 miles a day without fixing either a failed damper or broken piston skirt?

 

I do not think it is a Coil cop. I replaced the coils with no positive result.

 

Would a rebuilt ICE come with a nonfailing damper if I end up getting a rebuilt engine?

 

So I pulled out of the driveway this morning and I finally got my first codes. P3190 and P0A0F with the red triangle of death. I promptly put it in reverse and parked it in the driveway. I have not had a chance to replicate the codes. They do not help me but maybe the codes can help affirm one of the potential issues we have already considered in this post. Again, my desire is not to diminish the valued opinions calling for a new engine. I just want to take advantage of the learning experience before it gets replaced.

1. Do these codes help us with the diagnosis at all?

 

Do we have any good documentation or video resources for swapping a gen2 engine out of the top?

This is what I have found. Gen2 Prius Engine Removal Guide - Out the top of the engine bay | PriusChat

 

Well, I am no wiser as to what was the issue with the old engine but I did take the advice of the forum and replaced the ICE. I got it from a local junkyard for 300 bucks. I followed the directions from the Gen2 Prius Engine Removal Guide - Out the top of the engine bay | PriusChat Out of the Top engine removal post and had no problems. However, the junkyard engine did have some water on top of the plugs and gave me quite a bit of rattle until I got them replaced. I also had one bad fuel injector. Now that I have it running properly on the ICE side, My 7th cell in my battery is failing under load and will have to be replaced. Getting there! The only other time I have had a faulty battery was when I elected to let the car sit during the first month of lockdown and when I started it up about 3 weeks later I had some bad cells. I replaced them and no problem until now. It took me about 3 weeks to finish the engine swap and now I have a battery cell going bad again. I had run the Dr. Prius life test before the swap and everything was good. Is there a connection between the car setting and not running for 3 weeks and losing a cell?