10K oil changes are BAD! ??

Rebuilt engine

You can clear it everyday and it will come back on the next drive. It will mask a real problem.

 

True. The light came on within seconds of when the engine fired up.
I could check the codes with my Torquepro app everyday. Unlikely, will once a week be OK?

And what sort of code might pop up and be serious even though no change in performance is felt?

I feel I can feel the engine is smoother now. (I know.... a whole lot'o feelings.. Woe, woe, woe feelings....)
Can others do a quick check? (If you have the OBD dongle and the app to clear it.)
Or am I the only one that feels that: slight hesitation, stumble, non-response when adding just a tad of throttle....

 

Could you share a few reasons why NOT to unplug the EGR Valve?
I had a prius friend that has had many and goes to crazy high miles on his fleet of Prii tell me "It could Blow your engine."
I asked him technically what that means exactly. He couldn't say....

The theory is:
Mismatch EGR flow to all the cylinders due to more clogging taking place near the end of the EGR passages in the cold plastic manifold. Cylinder's 1 and 2 usually are where the head gasket fails, correct?
And that failure is due to detonation (?) in those cylinders due to insufficient EGR gasses in the mix, correct?

Therefore: Shutting off all EGR flow should make the mixtures all the cylinders get the exact same, correct?
And hopefully the ECM will keep things happy without that EGR flow, the way they do it in Brazil, correct?

This is probably not the thread to get into these details. Where should this discussion go?
I have plans to swap out the EGR parts with clean parts at some point. I have the spares waiting..
And I have plans to keep the EGR flow as hot as possible by insulating the pipe and spray foam the bottom of the manifold where the EGR passages are. I'll post pics when I have them.
This will all be long term testing. I'd wait for +50k miles on the modded EGR system to see if the intake passages are still clogging mostly near #1 and 2.

 

The arguments against egr deletes are weak other than legality in some areas and the check engine light.

MPG and emissions are secondary to a bad design which was redesigned in gen4. Even Mendel lets gen4 owners slide on egr cooler cleanings as they don’t clog up.

As stated before I would do it now if the light would stay off.

One of our resident programmers should code an obd2 scanner to read codes and clear egr related dtcs immediately while leaving them if other codes exist. They could display and alarm coolant temps while bumping the battery cooling fan when warranted.

 

Right. It might be illegal to drive around with a check engine light on in some states.
We have safety inspections on older cars are renewal time. I know they look at the ODO and maybe to see if there's a fault light. Definitely no emission testing. They don't have to go under the hood. Mainly brakes, suspension and exhaust is looked at.

To me the EGR cooler clogging is secondary to the main problem. That clogging might slow down the flow to the manifold.
But it's the clogging in the intake's tiny passages that creates the uneven flow between cylinders.
Isn't that the main suspect in this crime of design?

So I will try to check with my OBD reader 'often' while doing this experiment.
There is a dedicated Red warning light for engine coolant temp. This I know...
I saw it on a previous Gen3 while climbing the Rockies with a beginning head gasket failure.
No idea what you are saying about 'bumping the battery fan'....

 

Some apps provide manual control of the battery cooling fan but must remain connected to do so. Otherwise the hybrid system immediately takes over. Certain people think running the fan faster will benefit the battery.

Regarding root causes of hg failures, you look at the significant changes in gen4’s design including a cylinder wall insulator to even temps at that critical spot and egr collected after the cat among other things. I have posted documentation of these many times but Mendel’s cult like crusade drowns out the evidence. Not saying cleaning the egr is not useful; it keeps the check engine light off; but Toyota dealers would be selling the service if it had any real utility before a code.

 

Agreed. And if this service meant a long and happy life for a Gen3 engine why wouldn't this routine cleaning and servicing be in the Maintenance Schedule?
What's Toyota's stance on this 'Off the Book' servicing of the EGR system?

And do you really think that plastic doo dad stuffed in the open deck design of the block will really make a difference with Gen4 HG life?
Maybe there is less carbony crap building up in that EGR system. Who knows... time will tell if Gen4's are any better in the HG department....\

I'm hoping the latest SW update my Gen3 had has something to do with Water Pump duty cycle, the way it's mentioned in the TSB for Europe Prii. Maybe spinning the water pump faster while I'm cruising I-70 at 80mph uphill into the Rockies might help.... How? I don't know. Toyota mentioned it in that TSB... fingers crossed....

 

Oil changes are comparatively cheap enough to do every 5k for oil and 5-10k for the filter and oil is the most important fluid in an engine. I stick to that.

 

Agree. The reason on gen3 engines is new oil protects the rings better. Oil in the piston groves is highly fuel diluted in a low tension ring. Once the rings get carboned up it’s too late as blowby increases and is feed directly back to the intake by an egr system picking up exhaust and blowby before the cat. Gen4 fixed both factors and uneven cylinder wall temps.

 

“Blow by” is combustion gas getting past the piston rings into the crankcase. If it is getting into the intake it would be via PCV (positive crankcase ventilation) system only?

 

Yes you are right but the same rings allow oil in the combustion chamber which burns and partially ends up in the egr intake and further burns off in the cat. Once you have seen the massive carbon build up in the head you know bad things are happening. Down the road the dreaded P0420 means the cat is toast. Usually after the hg or engine was replaced.