EGR valve or timing chain or sensors or ECM

Background:
2010 Prius 265k miles. 6k miles since head gasket and timing chain and EGR/EGR cooler and intake cleaning (very thorough). Ran great since then... Until...

Current
Started with intermittent (1-2x week) severe stumble/rough running, at idle after warm up and in low rpm. At speed 45+. Seems to go away. CEL comes on and then after the car sits for a bit, it starts and runs just fine.

Codes are:
P0016 - cam/crank correlation
P0340 - camshaft position sensor bank A
P0403 -egr circuit malfunction

The codes would clear themselves after the first few times, then it would do it again within a day or two.

Now, when the car starts it seems to run fine, then after a min or two, it begins the EGR rumble and stumble. If I shut the car off and restart it runs fine again for a min then starts the really rough running.

So, my thinking was this. If the cam chain slipped a tooth, the problem wouldn't be intermittent right? It would be off and run like it's missing right from the first rotation of the motor, no? but if the tensioner was not working correctly, it could be a half tooth off and possibly compensating for the timing being slightly off, until it can't...

But the rough running was identical to the EGR issues in the past, so I purchased a new OEM EGR valve and cleaned the intakes again. Result was no change.

My next thought is that it might be an ECM issue as I've heard that these go bad and cause a number of the same problems in relation to the EGR circuit issue.

Before I open the timing chain cover and get into that, I thought possibly a cam chain sensor, but I doubt that would cause the code for the cam and crank sensor correlation issue, this leads me to think the tensioner has allows the chain to be a 1/2 tooth off, and maybe that's why it still seems to run fine when it was running?

So. New OEM toyota EGR valve and solenoid -no change, still have code for EGR circuit.

Nest step? Cam sensor or ECM? Or just dig in and address the possible timing chain and tensioner? I hate throwing parts, but I also hate paying for diagnostic and then paying for parts anyway when they will mostly come back with "it may be a couple things but we won't know for sure until we get into it..."

I bought what I thought was a quality timing chain kit when it was done with the head gasket? Maybe it wasn't and something failed, or maybe I did it wrong? But it ran great for 6k miles afterwards....

Maybe the ECM has taken a dump? Maybe all of the above at the same time?

 

As far as I could tell the block's fine as well as the head. I don't lose any coolant. There's no pink milkshake in the oil there's no oil in the coolant. The car wasn't overheating and it doesn't leak oil.

 

I did the work. I've done plenty of timing chains including Prius. I've owned three. Not an expert but I know enough to make myself dangerous... obviously.

 

This I understand, with a new OEM EGR valve and solenoid installed and the intake cleaned, and the EGR cooler cleaned put to ensure no blockage, (that took a long time with a bucket of chem dip and small pipe cleaner I made myself to get into the small passageways) I highly doubt it's the EGR valve... most likely the ECM or wiring harness to the EGR.

But would a slipped chain have an intermittent rough running issue? I would think if it s slipped a tooth, then the issue will be there hot or cold, no?

 

I put it in neutral and it idled fine. Wouldn't increase RPM because the check engine lights and etc all can back on, but it idled in neutral great! Put it in drive with foot on the brake and it started the violent sharing and stumbling, back to neutral, and it idled fine. Back to park and it started shaking and stumbling again.

Shut it off. Cleared the codes.

Started it again. Same behavior as before. Starts. And runs like it great for about 10 seconds then suddenly doesn't know what time it is... in neutral, purrs like it's supposed to, into park and shakes and misses like before.

Initially when I say the broken sprocket and sloppy crank sensor plate, I thought that may have been the reason this all started. The crank sensor couldn't consistently pick up the timing and confused everything things else. Now Part of me thinks that this violent shaking and stumbling may have been what broke the sprocket and allowed the key way for the sensor to get sloppy.

So here I am. With the codes above showing.

Could the ECM be bad? What else could be the issue? The oil drained had no coolant. The coolant had no oil.

I need help further diagnosis.. I am pretty handy.. I know enough to get my self in trouble.. as you can see.

Is there something I can do without tearing down the timing chain cover again?

Edited .. added the below info. I have found that the 12v battery will not hold a charge so I think it was only starting under the power of the jump pack and not the battery. Once the 60.seconds of "start engine" power from the jump pack, times out. The motor dies. Of course in neutral the traction battery does not charge and I can't keep it running in park because of the violent shaking. Could it be just really weak spark? Would the spark voltage required change from park to neutral? It seems so odd that neutral seems to run fine but park/drive no Bueno..

 

I am not sure what happened to the first few paragraphs of my original post. Yes. a lot of information is missing that was suppoosed to be there. sorry.

It is a contuinuation i will ask to have them merged


here it is

P0016 P0340 P0403 P3190
Back story: Car was running fine, then, one day it started running like it was missing terribly, warning light, check engine, etc. It ran similar to this event before and we figured out it was the egr cooler fully plugged, and. EGR valve. These were replaced. Car ran fine for a while.

Then we had a head gasket issue. We replaced the head gasket. Car ran fine for a while.

Brings us to current event.

Driving fine then terrible running, shaking, dash lights up, won't run. This was six months ago. It has sat since then.

At the time, the codes were related to the timing/crank and can sensors being out of sync. EGR, and low engine power. (Same codes as now)

I assumed that the chain, which had never been replaced as far as we know (bought used about 50k ago) either was stretched, the tensioner was bad or possibly slipped a tooth etc. So, this past week I did the timing chain. New Toyota OEM chain, guides, tensioner, timing sprockets, oil sprockets, oil pump chain. The works.

When disassembling the crank timing oil chain sprocket was found broken right at the keyway. The crank sensor timing plate behind it, they key was all hammered and the timing sensor plate was sloppy on the crank because the keyway was hammered. This is something I have never seen, granted I've only done about a dozen timing belts and chains in the last 30 years, so I have very limited experience. Anyway, I ordered a new sensor plate from Toyota. I had the new sprocket already.

I assembled everything. Ensuring that the cams and crank were timed correctly, then before putting the covers back on permanently, I spun it by hand and ensured that the crank pulley/dampener and timing marks on the cam sprockets all lined up as they were supposed to. All looked great, so I put it all back together. Car batteries were dead. Of course from sitting so long. Charged the 12volt, and then turned the car on. It started.

Ran and purred like a kitten for about 10 seconds then started running like it was missing terribly. Shaking etc. I put it in neutral and it idled fine. Wouldn't increase RPM because the check engine lights and etc all can back on, (limp mode i am sure) but it idled in neutral great! Put it in drive with foot on the brake and it started the violent sharing and stumbling, back to neutral, and it idled fine. Back to park and it started shaking and stumbling again.

Shut it off. Cleared the codes. Started it again. Same behavior as before. Starts. And runs like it great for about 10 seconds then suddenly doesn't know what time it is... in neutral, purrs like it's supposed to, into park and shakes and misses like before.

Initially when I saw the broken sprocket and sloppy crank sensor plate, I thought that may have been the reason this all started. The crank sensor couldn't consistently pick up the timing and confused everything things else. Now Part of me thinks that this violent shaking and stumbling may have been what broke the sprocket and allowed the key way for the sensor to get sloppy. So here I am. With the codes above showing. Could the ECM be bad? What else could be the issue?

The oil drained had no coolant. The coolant had no oil.

I need help further diagnosis.. I am pretty handy.. I know enough to get my self in trouble.. as you can see.

Is there something I can do without tearing down the timing chain cover again?

 

Hi Mendel,
This is not the 2006- its my sons 2010. and it technically is a continuation of a previous post from last year. sorry abouty that. EGY cooler and valve/solenoid have been replaced.

 

Yes! End of the World is correct!

 

would it sound like its idling fine in neutral/no load, if it had bent valves? possibly I guess it could. I will compression check.

 

It's running very well now. So. Summary... Something happened that caused the oil pump chain drive sprocket to break. This "something" was also severe enough to cause the crank sensor timing plate to widen at the keyway, and causing enough play that the crank sensor couldn't pick up and get correct time.

I believe that this "something" was a severe misfire or multiple severe misfiring from issues with the head gaskets or EGR being clogged.

or,
It was caused by me, when I replaced the head gasket and placing too much torque on the crank bolt as these sprockets are all stacked on top of each other behind the crank balancer

Anyway, the play in the sensor plate cause physical damage to the crank sensor, just slightly, that I didn't pick up on when inspecting it the first time.

So I Replaced the crank and cam sensors, again..

See the attached picks. You can see the keyway in the sensor plate all banged up and widened this cause considerable play in the sensor plate as it spun.