Prius III engine knocking at high torque low RPM (solved)

Too bad. Thanks for thinking with me though! Hopefully there's somebody else that know how to get this off?

 

It's a plastic (or nylon) wire retainer type clip... but it's a pain to get to it.

You have to pinch the retainer from the rear and it latches from left to right. I used right angle pliers to pinch it while using a flat screw driver to place upward pressure on the clip. (Seems like a door panel trim removal tool would have been easier than the screw driver.)

Be patient and keep working it... it will come.

Did you just remove the EGR pipe or did you remove the entire intake manifold and throttle body out of the car?

There is a real problem inside the intake manifold and you have to remove it to clean it...

 

so i took apart everything and found carbon deposit of bad kind. now what should i use to clean it up, it is not greasy carbon it is rigid solid deposits.
[/url] [/IMG]






































now i need to know what should i use to clean this?. i bought throttle body cleaner from autozone but it mentioned that it may damage the plastic or painted surfaces. now the manifold is all plastic so i am hesitant to use it on that. what should i use instead? any suggestions?.

 

Could use the throttle body cleaner just don't get it on your car's painted surfaces. You could also use gasoline.

Actually yours does not look that bad... the small holes still look open. Was you car having problems?

 

Spray the cleaner on a cloth and clean with that. Don't spray directly.

 

Just for clarity... The post/problem is concerning the intake manifold.... the video is on a different subject - the throttle body.

These are very different issues. The intake manifold is a more involved project.

 

I had this problem, posted about it, a little over a year ago. The dealer replaced the EGR at a total cost of $765.00. Only to have the problem return almost a year to the day. I would've fixed it myself but I feel the prius is a a bit harder to diag with intermittent engine running. Took care of it myself the second time around.

 

Hi there,

I was wondering what kind ot "clamp" did you use to prevent coolant to flow when removing the intake manifold ? Also, don't you need to drain the coolant as there might be some air inside the cooling system ?

 

Thanks for checking in, Bert. Like you, I'm at ~20k miles since cleaning up the intake manifold and egr pipe and the car is still running well. Yes, the carbon deposits were "oily" and my 2010 uses zero oil. No doubt it's fuel or fuel vapor creating the sticky consistency of the carbon build-up. It's messy stuff to work with.

EGR was not blocked. Did you have check engine light/P0401 when your EGR was hack blocked?

 

A poster in this or one of the other IM cleaning threads stated that he left the coolant hoses connected to the TB, simply unbolting the TB and letting it hang by the hoses, thus not losing any coolant. To do over again, I'd just do this. Clamping off the lines is certainly an option, too, if you want to bring the TB to the bench to give it a proper scrubbing. I didn't, and the amount of coolant lost is minimal. I had to add maybe an ounce or 2 and I simply burped the lower hose a few times with the car at operating temp. It seemed to me that the burping didn't even seem to displace any air... A full coolant drain/refill is not in any way needed here.

 

Thank you for this post. Amazing! The pictures are great too. I am not a mechanic or car savvy ... just do the simple things like changing oil, air filters, etc. I will bring a copy of this post, along with your pictures, to a mechanic. I have a guy at Pep Boys who is Korean and used to work on Toyotas that I always request. He typically does good work. I may take it to him first as I think he would be more open to fixing. Great Post ... this is a great site ... really glad I signed up and posted my problem here.

Last follow up question ... if this doesn't fix things, what would be the next order of things you would check? IE: Spark plugs? Dirty Throttle Body and Intake Manifold? These were suggestions from other posters. (Already did the spark plugs about 8 months back and the problem started a month or so after this.)

Thanks!

 

Yes. My carbon deposits were very oily.

I go through about a quart of oil every 800 miles.

 

Yikes! How many miles on the odometer?

 

204000. But it's been an issue since I took ownership at 75k

 

I think we have a solution:

It turns out that disabling diesel EGR in cool weather is a common technique in the EU diesels:

• VW Faces $17B Fine for Emissions Scam | Page 68 | PriusChat
• More Diesel Emissions Irregularities Uncovered By Real World Testing - Gas 2

I speculate that a prior owner thought this diesel technique would work with the Prius. We don't know what the original blocking plate looked like but it may have also had a small hole to reduce the flow. The EGR gas and pressure further opened the hole but the low flow rates led to the coked up EGR and tube. Who did it is an open question.

If it were a common practice at the dealer, there should be more. At one time, I would have been skeptical of a rogue dealer but VW punctured that trust. However, there is another report that in the UK some independent shops have been opening a hole in the particle filter canister, removing the filter, and closing it up again. So putting a block on the EGR may be a common, independent shop technique like gutting the particle filter trap to improve diesel performance and reduce maintenance costs.

We know in the USA the "rolling coal" owners seek out a software patch that allows them to create huge clouds of soot. It is entirely possible that a similar practice, not for clouds of soot, exists in Europe to improve diesel performance. An EGR blocking plate and gutting the particle filter would be low-tech and easily avoid detection in the past.

I am beginning to think portable, non-contact, emissions testing is the way to go. Today, they are established by the side of the road. In the future, they need to be on the front of public service vehicles with a license camera.

Bob Wilson

 

Well, I have the same strange shake behavior when accelerating in low rpm. Where should I start? First thought spark plugs but after reading here it might be best to start with EGR pipe cleaning and maybe Throttle body cleaning. Should I really bother taking off the whole manifold? BTW I do have the check engine light on now but have not read out the code. Should I go to get it read first? Can I reset it myself? Thanks guys for putting all this up.

 

MiniVCI and Windows XP laptop. This will let the two dozen control computers tell you what is broken:

1. Diagnose problem
2. Fix problem ... don't confuse 'parts swapping' with a diagnosis.

Bob Wilson