Aftermath of EGR Cooler Cleaning Project

Maybe a recording would make more sense.

You said in a post above

“Only idling seems to be the issue. Car just idle while in the neutral/park mode. It’s shaky, noisy and dies.”

I don’t get what you are saying. Are you saying the problem is only at idle and the engine does not turn off like normal, eg it does not revert to ev mode?

Does it misfire at idle? Does it make a severe metal to metal sound like something is broken?

The engine dies? Does this mean you have to restart it?

 

Also…. Reading your old posts from last year you had a 2010 Prius with a blown head gasket and water in the oil. You changed the head gasket but it did not go well. You then bought an Avalon hybrid.

So is the current problem on the same 2010 Prius? Are you buying Prii and fixing them for resale?

At the beginning of this thread you said the current car was running great until you did an egr clean.*

You used strong solvents on the intake with the maf sensor installed and were waiting on an eBay maf. I would assume that maf is an aftermarket unit which are almost never good.

Now some vacuum leaks were found on the intake and the egr plus you posted pictures of a poorly fitting throttle body with perhaps something jammed between. That sure looks bad.

Confused…

*See Mendel’s sideways signature for more egr information

 

Two of your codes (P0123/P2135) relate to the ECM seeing bad information from the TB. I don't think you would get those codes because of a vacuum leak, as they are triggered by electric signals. Although I have never heard of a TB being damaged by WD40, I have also never heard of anyone cleaning it with WD40 so can't say what the correlation might be.

You can't go by the value given by the ECM through a scan tool as the means to test a TB, as the issue is a bad signal from the TB to begin with. You need to test the voltage output to/from the TB connector itself.

A bad TB signal COULD cause the hunting, because the ECM is expecting certain parameters (rpm, air intake, etc.) based on where it 'thinks' the throttle butterfly is positioned. When it doesn't see the right correlation between the throttle (because of bad/incorrect signal) and how the engine is running, it tries to 'find' the right parameters using various other variables (ignition, fuel, adjusting throttle, etc.). This can cause the "hunting" action.

It's a similar problem with older cars that have bad idle air control valves that go bad.

That being said, I would PERSONALLY never trust a MAF from Ebay unless it was from an authorized dealer (some do vend on Ebay). There are a LOT of counterfeit parts - especially electronic - being hawked on Ebay and Amazon.

 

I should also state that I am not completely familiar with the TB on a Prius, but some TBs are VERY sensitive to having the butterfly/plate being moved manually (especially when disconnected from the circuit) like what some might do while cleaning.

 

I’ve done that (with our 3rd Gen Prius) , no ill effects.

 

Was the manifold cracked, or was it the gasket?
Why waste fuel? After the car is "ready", press the "ev" button.
Then drive the car under 9mph. Depending on traffic where you are
and charge of your battery, you should be able to drive a tenth of a mile
or two before the engine kicks in.

The knock your describing sound like the clutch engaging and disengaging.
When could be a failing head gasket....

P.S. Unless, when you park the car for the evening, it's cooler out and the
engine is hot. Then you get condensation.... That will cause a little knock,
but only for a second or two.

 

Sounds like you had it figured out back in May but did not pull the trigger on a new manifold until a shop convinced you.

 

That is what I did. Be sure to set an alarm for ~215f so you will be notified earlier than the car’s 248f.



There are other codes as well so I keep a Bluetooth interface in the glove box to quickly determine what the code may be. You can get inverter and mig over temps as well.



All to avoid a breakdown

 

An over heating engine certainly could cause the head gasket to fail, it's more likely
the gasket fails and cooland leaks INTO the cylinders. That causes missfires and the
hybrid system trying to start the engine and the clutch engaging and disengaging.



Since there's no temp gauge on the dash, I ordered a little ODB2 display which'd display the real time engine coolant temperature on the dash. I am scared of the head gasket failure, I wanna drive this car as long as possible.
If the temp is rising beyond normal I wanna be able to pull car to the side and let it cool down.[/QUOTE]

 

I bought the earlier P10 years ago. It is hardwired to the obd2 port and has an automatic sleep mode that has to be configured in the device to avoid excessive parasitic draw from the always powered obd2 connector.

The P10 configuration allows multiple screens but I chose two items with coolant temp and actual mph. Both have alarms set. I have only heard the speed alarm (set at 78 for the freeways around here). I stay below the 85mph limit on 130 for the sake of the engine.

The Bluetooth interface plugs in the same connector when needed and communicates to various phone apps. My go to app is Car Scanner for iOS. I also have Dr Prius but rarely need it since I bought a new oem battery instead of an unreliable aftermarket new or refurb used battery.


$26 on Amazon (some cheaper interfaces have issues)