Auris hybrid EGR System clean

[TonyHSD]

Hi all, 

after 3 years and another 105k miles  traveled the egr system needed some attention. This time seemed to me slightly better than the first time when I opened at 140k miles, I did not have the knocking sound on cold starts however there is an increased oil consumption around 2 litres per 10k miles and as planned maintenance I decided to do it today. 
Valves and injectors look very clean with only traces of oil. Throttle body very similar condition, mostly oil and some oil was seating at the bottom of the manifold and inside pcv hose and pcv valve. Egr cooler was blocked with soot as well as the egr valve, both cleaned nicely using Holts egr and carb cleaner sprays x4 and brushes and a specialist spoke to get through the fins. Manifold cleaned and washed too. All good but takes ages to be done so tomorrow will be part two, putting back all together. The metal gaskets looked worn, but that’s normal after been already used twice and more ., got new one and a new pcv.
Why its important this procedure to be done every 100k miles or so. When egr system gets blocked the engine starved for air when at low load and the air intake is sucking air from the pcv which sucks engine oil too. This is explained by us Prius specialist and make sense to me. Also the hose from pcv to the manifold was full of oil too. Here some pictures from today’s work and tomorrow will follow more. 

 

 

[Marius991]

Hello,

Is it all production year Auris and Prius 1.8 hybrids is affected by this egr problems? I know that ICE running on Atkinson cycle and gases goes to intake and etc, but maybe Toyota changed some software or hardware to issue the problem?

[TonyHSD]

2 hours ago, Marius991 said:

Hello,

Is it all production year Auris and Prius 1.8 hybrids is affected by this egr problems? I know that ICE running on Atkinson cycle and gases goes to intake and etc, but maybe Toyota changed some software or hardware to issue the problem?

 Hi Marius, 

yes all Toyota hybrids won’t egr will have the same thing. I can’t say it’s a problem or issue it’s just how the things work. Egr cooler, pipes, valve, manifold all get clogged with soot after some time and mileage. The reason I clean those is to prevent real problems from happening as a result., these can be engine knocking, head gasket failure, clutch springs, high oil consumption. Later models and M series engines has different design and probably will suffer less but for sure even they will need cleaning at some point. My car is 245000 miles, first clean done at 140000 and now . 

[Marius991]

40 minutes ago, TonyHSD said:

 Hi Marius, 

yes all Toyota hybrids won’t egr will have the same thing. I can’t say it’s a problem or issue it’s just how the things work. Egr cooler, pipes, valve, manifold all get clogged with soot after some time and mileage. The reason I clean those is to prevent real problems from happening as a result., these can be engine knocking, head gasket failure, clutch springs, high oil consumption. Later models and M series engines has different design and probably will suffer less but for sure even they will need cleaning at some point. My car is 245000 miles, first clean done at 140000 and now . 

Wow, big numbers and your hybrid continues to go strong. Any major issues you had? I hope my hybrid get at least half your mileage :)

[TonyHSD]

1 hour ago, Marius991 said:

Wow, big numbers and your hybrid continues to go strong. Any major issues you had? I hope my hybrid get at least half your mileage 🙂

Well I think the mileage it’s not as high as some other owners had. There are cars like this way higher miles without major problems. My one also been trouble free mostly. Only had once hybrid system malfunction, nothings was broken and I actually  didn’t find out what exactly has caused  it. Two rear wheel bearings failed, changed twice and once front wheel bearings and two rear springs and timing chain tensioner. Three sets of brakes , that is all for 13 years. Your car has the same engine and I don’t see a reason why won’t go as far as mine and even more, 👍

[Davidhee58]

On 5/17/2023 at 8:34 PM, TonyHSD said:

Hi all, 

after 3 years and another 105k miles  traveled the egr system needed some attention. This time seemed to me slightly better than the first time when I opened at 140k miles, I did not have the knocking sound on cold starts however there is an increased oil consumption around 2 litres per 10k miles and as planned maintenance I decided to do it today. 
Valves and injectors look very clean with only traces of oil. Throttle body very similar condition, mostly oil and some oil was seating at the bottom of the manifold and inside pcv hose and pcv valve. Egr cooler was blocked with soot as well as the egr valve, both cleaned nicely using Holts egr and carb cleaner sprays x4 and brushes and a specialist spoke to get through the fins. Manifold cleaned and washed too. All good but takes ages to be done so tomorrow will be part two, putting back all together. The metal gaskets looked worn, but that’s normal after been already used twice and more ., got new one and a new pcv.
Why its important this procedure to be done every 100k miles or so. When egr system gets blocked the engine starved for air when at low load and the air intake is sucking air from the pcv which sucks engine oil too. This is explained by us Prius specialist and make sense to me. Also the hose from pcv to the manifold was full of oil too. Here some pictures from today’s work and tomorrow will follow more. 

 

 

 

On 5/17/2023 at 8:34 PM, TonyHSD said:

after 3 years and another 105k miles  traveled the egr system needed some attention. This time seemed to me slightly better than the first time when I opened at 140k miles, I did not have the knocking sound on cold starts however there is an increased oil consumption around 2 litres per 10k miles and as planned maintenance I decided to do it today. 
Valves and injectors look very clean with only traces of oil. Throttle body very similar condition, mostly oil and some oil was seating at the bottom of the manifold and inside pcv hose and pcv valve. Egr cooler was blocked with soot as well as the egr valve, both cleaned nicely using Holts egr and carb cleaner sprays x4 and brushes and a specialist spoke to get through the fins. Manifold cleaned and washed too. All good but takes ages to be done so tomorrow will be part two, putting back all together. The metal gaskets looked worn, but that’s normal after been already used twice and more ., got new one and a new pcv.
Why its important this procedure to be done every 100k miles or so. When egr system gets blocked the engine starved for air when at low load and the air intake is sucking air from the pcv which sucks engine oil too. This is explained by us Prius specialist and make sense to me. Also the hose from pcv to the manifold was full of oil too. Here some pictures from today’s work and tomorrow will follow more. 

Very good job Tony, I watched some videos, it's not easy to remove the EGR cooler, as the bottom bolt is very difficult to access, do you have an easy way or special tool to undo the bolt?  To make the job easier for the future EGR service, some people just ignored the bottom bolt when they put the cooler back to the engine body, as the bottom bolt is not necessarily needed, do you do that as well?

[TonyHSD]

4 minutes ago, Davidhee58 said:

 

Very good job Tony, I watched some videos, it's not easy to remove the EGR cooler, as the bottom bolt is very difficult to access, do you have an easy way or special tool to undo the bolt?  To make the job easier for the future EGR service, some people just ignored the bottom bolt when they put the cooler back to the engine body, as the bottom bolt is not necessarily needed, do you do that as well?

Hi David, 

The lower nut as they call hidden it’s almost impossible to take off and put back on. I have a combination of bars and sockets with insulation tape on the socket to hold the nut and even so it’s very difficult indeed. I also work with wipers arms and plastic surround on, I don’t remove these either.,  the rear two nuts and bolts are also difficult to remove ,  it’s time consuming job especially for diy people. And if you drop anything which always happens and can’t get it out with the magnet which also is a norm then you need to lift up the car to open the service cover and search for the bits., the cleaning of the cooler is also time consuming and labour intensive job. Here my set up for the lower nut and some more pictures. These combo socket and bars goes between the high voltage cables and over one black wires loom. It needs to be exact length, no more no less, best to have various extensions so you combine these and see which one works best for you. 

 

[Davidhee58]

yes, it's a very time comsuming job, no garage will be willing to do this kind of job, and just replace it with new one. Do you think the cooler lower nut is really needed? will it cause any problem without it?

[AisinW]

Your EGR looks normal and no clogging Tony. My throttle body is also always full of oil and fuel after 2 years/20k miles.  The intake manifold 4 small holes that connected to the EGR pipes are the one that we should clean really well. It prevent pinging and loss of power under mild load. 

I also plan to clean the intake manifolds and EGR cooler but probably after 150k miles.   I inspect the L pipe right after EGR and it was still clean. If it starts burning oil, 1L/5k miles or more, then cleaning these EGR mess every 90k miles is a must. 

[TonyHSD]

33 minutes ago, AisinW said:

Your EGR looks normal and no clogging Tony. My throttle body is also always full of oil and fuel after 2 years/20k miles.  The intake manifold 4 small holes that connected to the EGR pipes are the one that we should clean really well. It prevent pinging and loss of power under mild load. 

I also plan to clean the intake manifolds and EGR cooler but probably after 150k miles.   I inspect the L pipe right after EGR and it was still clean. If it starts burning oil, 1L/5k miles or more, then cleaning these EGR mess every 90k miles is a must. 

150k miles its a bit too late imo, although some people never cleaned and went over 200k miles. 
My first opening was at 140k miles but then the car was badly knocking not only on cold starts but also when engine was loaded to recharge the Battery and I was driving slowly 20mph or less and release accelerator, omg it was like an old tractor. When this happens you can get clutch springs broken too, on top of the head gasket risks  and oil burning. 
This time I didn’t have any knocking, the egr system looked cleaner but still was bad enough and worth cleaning it. Here the cooler was totally blocked because the cleaner couldn’t go through it , I had to soak for two hours and push through with a metal spoke . The Holts cleaner works wonders. Best product to use, avoid any other chemicals and particularly those for kitchen use. Egr valve was also dirty enough, I haven’t touched the actuator on top, if any issues further I will open and push that band lube with wd-40. 

https://www.ebay.co.uk/itm/352709894974?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=MQfZam35TmK&sssrc=2349624&ssuid=p34UK1z2T4m&var=&widget_ver=artemis&media=COPY

[TonyHSD]

45 minutes ago, Davidhee58 said:

yes, it's a very time comsuming job, no garage will be willing to do this kind of job, and just replace it with new one. Do you think the cooler lower nut is really needed? will it cause any problem without it?

It might not cause any  issues but if you able to take it out then you should be able to put  back on and always better to do the things as per the book. 
Garages are doing this, even main dealers, they clean the parts and replace the egr valve to guarantee the work. They do charge well for that but I have no idea how much. 

[Marius991]

1 hour ago, AisinW said:

Your EGR looks normal and no clogging Tony. My throttle body is also always full of oil and fuel after 2 years/20k miles.  The intake manifold 4 small holes that connected to the EGR pipes are the one that we should clean really well. It prevent pinging and loss of power under mild load. 

I also plan to clean the intake manifolds and EGR cooler but probably after 150k miles.   I inspect the L pipe right after EGR and it was still clean. If it starts burning oil, 1L/5k miles or more, then cleaning these EGR mess every 90k miles is a must. 

Hi, what's your mileage now? You ever cleaned intake or egr cooler?

[AisinW]

Thanks Tony. I will do it at 140k miles then, My car does not burn any oil and I mainly drive in the motorway or state roads without traffic jam.  

@Marius991 I never cleaned or open the intake. Only open the throttle body, EGR valve,  and the elbow pipe. those are relatively easy.  When putting the EGR valve back, make sure you screw in the magnet in completely or it will be stucked opened and your car will misfire badly (don't ask me why I know it).   The EGR should be free when we press the valve. It is electronically controlled by the stepping motor (black plastic). 

I think, the EGR valve cleaning depends on how our car runs and used. If we drive mostly highway and consume no oil, the EGR will have less carbon too. 

[TonyHSD]

I drove the car last night and it seems better than before the cleaning. Engine is slightly quieter and does not rev up unnecessarily like before, smother transition between ev and petrol , smoother turn off too.
This change could be the throttle body related and the new oil , but overall happy with everything. Worth the effort 👍

[AisinW]

Everytime we clean the throttle body, the ECU sometime gets confused a bit and adjust with the clean throttle plate after few hundred miles. I think it runs quiter from new oil, smooter from cleaner EGR passage and balance the cylinder EGR air volume. 

My car always rev up a bit right before the ICE off. I think it is normal, not sure why but probably to reduce vapour on the throttle body before it shut off. 

[TonyHSD]

1 hour ago, AisinW said:

Everytime we clean the throttle body, the ECU sometime gets confused a bit and adjust with the clean throttle plate after few hundred miles. I think it runs quiter from new oil, smooter from cleaner EGR passage and balance the cylinder EGR air volume. 

My car always rev up a bit right before the ICE off. I think it is normal, not sure why but probably to reduce vapour on the throttle body before it shut off. 

Indeed. 👍

When throttle body and egr are cleaned a good practice is to disconnect the negative terminal of the 12v Battery, I did that too. Yeap, rev up confirmed, all hybrids behave the same. 

[AisinW]

Cleaning EGR and intake regularly is a very good habit to prevent worse problems such as head gasket failure.  The head gasket failure is at alarm rate in the USA where people drive 15-30k miles per year.  It is a combinations of bad oil change habit, oil quality ($25 quicklube change), E10 with actual 10% ethanol, and lack of maintenance for many Prius 3 owners there.   Most European Prius owners love their cars more and maintain them better with a good oil.  The snow ball started with oil consumption as high as 1L per 500 miles and cause sticking EGR valves and clogged EGR passages on the intake manifolds.  Without a good EGR flow, the engine runs HOTTER.  Hotter means = head gasket failure. The 10% ethanol in the USA makes things worse because it causes  LEAN mixtures = hotter engines.   Fortunately, E10 in europe is usually 6% or less ethanol and we use Super 95 instead of Regular RON91/AKI87 gasoline. We never find any RON91 anymore in europe. 

I attached the newest revision of the head gasket of 2ZR-FXE that reduce a lot of problems. 

[Saxmaniac]

As an aside regarding HG failure, car care nut recently did this video, HG design changed from about 2015. He mentions not to believe long life coolant claims but change at half the specified miles/time to protect against attacking HG 

 

[AisinW]

I think he is partially right about it. It is not just the coating but the bulge parts of the head gaskets that getting flat. 

There is no clear concern that super long life SLLC causing it because we have no problems in Corolla USA with 90% similarity. 2ZR-FE in non hybrid since 2003 are very durable and rarely have any head gasket problems even beyond 300k miles. 

It is the amount of cycle of On and Off, cold and hot in Hybrid combined with EGR clogging, oil consumptions, pinging from 10% ethanol and lack of maintenance cause high rate head gasket failure in the USA. European have much lower head gasket problems because we travel much less than typical american, no 10% true ethanol fuel, better engine oil not cheap mineral oil from $20 quicklube, and more stringent TÜV and MOT. 

We have similar issues with old NVidia GPU long ago in Laptop but not in Desktop because of hot and cold cycle cause cracked on the chip cooling layers.

But still, Prius 2 and Yaris has no issue at all with head gasket. The same thing with 2ZR-FXE  post fall 2014

[JCT-DK]

So you are saying the engine 1NZ-FXE in Yaris is different and has no issues of Gasket failure?

But it still has a risk at clogging the EGR, intake manifold and Throttle head?

How do you lower the risk of clogging? 

Thanks!

[AisinW]

1NZ engines has tendency to consume engine oil at higher mileage but not excessive like many 2ZR-FXE pre fall 2004. I am not aware that Prius 2 have EGR problems either. It is related to oil consumption.

Yaris Hybrid and Prius C has much less poblems in engine and transmission than Prius. It is just too small for a family car and less comfortable than Auris.

[Saxmaniac]

There's a method of measuring egr flow in Techstream, I've not done it but if you have an unofficial version of TS it's a way of keeping a check without dismantling Egr. Other more expert people than me here might have further comments on this 

[JCT-DK]

Anyone knows if its possible to make readings on the egr flow in the obd Carista?

[AisinW]

On 7/10/2023 at 11:02 AM, JCT-DK said:

Anyone knows if its possible to make readings on the egr flow in the obd Carista?

Probably Torque Pro with Prius3 PID has the option with any ELM327 OBD2 protocol (Carista, Veepeak, Panglong, etc.)

[Saxmaniac]

I think when you have a tool capable of reading flow value, you need to take readings under particular conditions like steady throttle cruising so egr valve is fully open. I don't know for certain as I've never done it and would have to research properly. I'm of the opinion that you can waste a lot of time trying to justify to yourself avoiding some maintenance when you might just as well spend the time doing the maintenance! So really, just do it around 100k miles and have done!