EGR circuit concerns from a Toy indy shop

wow, what a great asset for the twin cities, sounds like they actually care!

sounds like toyota has moved on to gen 4.

 

Imagine that - I got a P0401 on my 2010 this morning. P0401= EGR flow insufficient detected.

 

thanks for the link, it's good info for people who are not familiar with the issue.
the only reservation I have they are combining 3 types of knocking into one:
1. harmless rattle when combustion chambers are wet (from previous shutdown on cold engine)
2. problems with dirty EGR system that can be fixed by cleaning
3. failed HG.

 

Some people here like @danlatu are convinced #1 is not harmless and may lead to #3.
Their solution is an oil catch can to resolve or reduce #1 before it progresses to #3.

 

1. is very bad for any engine, it is going to turn into a failed head gasket. That knocking will deteriorate the seal on the three layer steel head gasket and cause it to leak = blown head gasket. I have posted a video with two different prius that do not knock at cold start up, with multiple shut down and start up with engine block still cold. It knocks because oil/water/fuel are sucked into the combustion on start up from the intake plenum. While your car is driving, hot gases along with oil/water/fuel in mist/spray is coming from the crankcase, also known as blow-by. This owf circulates through the pcv and into the intake plenum. It you take off your throttle body you will see standing owf at the bottom. Cars are not meant to combust more than 14 parts air and 1 part fuel (these numbers change in temp, altitude, humidity, load etc) not 14 parts air 1 part fuel and OWF that is sitting in the intake plenum. I have not cleaned the egr in our 2010 and have an oil catch can inlace since 80k and have not had one cold start knock with 117k on it now. My 2011 has 306k with no knock because = oil catch can (occ).

DEBUNKED ! Cold start , stop , restart = No knock | PriusChat

 

I realize that is mighty kind of Toyota to offer such assistance...but... 10k & 3 months ago I swapped the EGR cooler & valve for a cooler & valve that I had purchased on ebay. & cleaned up myself. Cleaned the whole EGR circuit & replaced the plugs at the same time. Very shortly later I installed the OCC. Prius ran good for a while. I put 4-5k on it around town & then took it on a 4100 mile trip. In the middle of the trip it started to idle a little rough at times. Sometimes it runs great & other times (like now) it has problems. I need to tear into the EGR circuit again & look around. I'll probably swap in the OEM (cleaned) EGR components at the same time as I look around.

The 4100 mile trip consumed 3 quarts of 0W-20 oil. Much of my driving was at 75mph - it is difficult to stay at 70 & not get run over :-/

I started the 4100 mile trip with an empty OCC. At the end of the trip the OCC contained 2.2oz & there was a puddle of oil in the intake manifold. I removed this oil & Prius ran OK for a while so it could be the oil has returned? After reading what I just wrote I need to go digging for oil (check below the throttle body) as a first step - I'll keep everyone updated as I find out more.

 

Yeah, I was not going to wait around for a light/code and complete EGR clog up. That's like waiting till your oil pressure light comes on before adding oil. I didn't relish an inept dealership tearing into it either.

Actually, with the rate our miles are accumlating, doubt that light/code would ever happen, it'd be partial clog limbo.

 

I took our intake manifold off a second time, about a month after OCC install, and was a little dismayed to see oil sheen at the low point, below throttle body. I also saw "tears" of oil under each intake port, fwiw.

 

i wonder if the pip engine will wind up worse because it spends so much time in the warm up cycle? i don't recall any problems to date.

 

The occ need filters. I could imagine without the occ, it would be worse. Just to much blow-by or pcv sits to low in the engine bay.

 

Are you sure you didn’t shed any tears after seeing the oil ?

That’s a lot of work you’ve done at such low miles.

 

Well my OCC did catch a lot, especially so far this winter.

 

Are you doing 10k oci? You may be experiencing more oil dilution in cold weather (more fuel/water contamination breaking down oil). If the oil is diluted, more oil/water/fuel mist will get thrown through the pcv and into the occ. I do 5k oci in winter and 7.5k in summer. I have not played with enough occ to know which is the best design.

 

Last oil change was on 110217 at 224683 miles with 11269 miles on the oil. I had added 1.2 qts of make up oil (all of this driving was on surface streets, no interstate driving) & I was trying to keep the oil fill level somewhat below full. Oil has always been Mobil1 Extended Performance 0W20.

After this last oil change on Nov 2 I had put about 1300 miles of interstate driving & 1700 miles of surface street driving on the Prius before taking off on the 4100 mile trip. Shortly into the 4100 mile trip I gave up on trying to keep the oil fill somewhat below the "full" line. I was trying to add oil at every other rest area. I started adding oil to just below the full mark & then check the oil, adding more when it was below 1/3 full.

The Prius "lives" in south FL, so it never sees cold weather. 40's here is COLD! Prius did see some freezing temps in Texas & Indiana but not for long. My stay in Indiana was for a grand total of 20 hours - just too cold for me & I kept hearing S FL calling

After installing the OCC & before the 4100 mile trip I was checking the OCC at 3-500 mile intervals. I was finding a little oil & absolutely no traces of water in the OCC oil. My OCC has a small threaded cover below the intake like that I installed a piece of SS pot scrubber as a small filter.

 

Yesterday i cleaned the oil from below the throttle body. There was lots of oil sitting there, at least 3/8" as shown on the small screwdriver in the pic.

This is only about 1600 miles of driving since I cleaned this after returning from the 4100 mile trip.
Took the Prius out for a drive & most of the stumbling seems to have cleared up. Need a longer drive to be sure.

Presently I am running without a OCC. I have another OCC on order but I needed this one so I could figure out some mods to let it work much more efficiently.

Another thing: I'm still on the original PCV valve. I have never removed or cleaned it. I have a OEM replacement that I keep forgetting to install. This could be part of the problem.

 

I keep wondering how the MAP sensors function, just swimming in this swill? I'm not exactly sure what they do, lol. But being virtually immersed can't help, lol.

What OCC have you got on order?

 

I ordered the same style as I have now. These pics are from Dec 3, after 3-400 miles of around town driving.

I'm in the process of making some circular baffles that that stack below the top & create a long winding path for the oil mist.

This is the can that trapped the whole 2.2oz during my 4100 mile trip.