Hello Dear Durango owners!

I have 2016 Durango with 3.6 ERB engine. I'm struggling with P105D and P0301, while mostly P105D as "pending", P0301 rarely, but eventually finishing with CEL.

Replaced spark plugs, coils exchanged from left side to the right side. Dodge repair shop suggested replacing VVT solenoids on left side (1-3-5) for a bag of money covering 6 hours(!) of worktime, but finally agreed that it should be enough to replace left ones with rights ones to confirm that they are the reason. They were not.
Checked compression: equall on all cylinders.

Recently I found perfectly repeatable pattern which leads me to the conclusion that the reason it rather not mechanical:

Hot engine starting. Pressure reported on dash falls from 4 to 2,1 bar in less then 5 sec. Engine working ~1000 rpm and working smoothly.
25-40 seconds from start: rpms decrases to ~600. Intake pressure 40kPa. O2 sensors working more or less fine, and the same relative to each other.
For 80 seconds it works fine and nice.

80 seconds from start with damn accuracy of +/- 5 seconds, intake pressure instantly drops to 30kPa, I can hear a quiet short pfff somewhere, and engine starts to vibrate. Oil pressure on dash falls a bit to 2.0 bar. Then O2 sensor on bank2 looks pretty normal, while on bank1 is extremely distorted sine wave (like electric noise - lots of little up and downs but still more or less in sine shape)

Then I stop the engine, start again and there happens exactly the same pattern. It behaves different when starting cold - works nice for a longer time but finally ends in the same place.

What hapeens 80 seconds after starting hot engine?

Another thing I can see on simple OBD scanner is "EGR error" which starts to show like 90-100% peaks exactly when engine starts to vibrate.

I would be grateful for any suggestions.

Dodge repair shop is less then helpfull here, with suggestions to part by part replace whole car starting with tail lights...

 

The computer runs off tables, not sensor data, until it warms up. I imagine that when it's already warm that it's running off the same tables when it first starts, then it probably switches to sensors after that 80 seconds once the computer is satisfied that everything is working correctly.

If you're getting an EGR error, try unplugging the EGR valve and see what happens. It'll throw an error since it won't see the EGR, but the EGR itself won't operate. The EGR's purpose is to spit exhaust gas into the intake to help it run cooler, but it has to be a measured amount. If the valve is throwing itself to max opening, the engine isn't going to like it. It looks like the EGR is on the driver's side of the engine, right next to the throttle body, so if it's opening the EGR to max then it could be affecting the O2 sensor on that side. If the engine runs smoothly for more than 80 seconds, you've found the problem.

 

Thanks for response Vimes. Looks like it's not EGR issue as after disconnecting it runs exactly the same way + OBD error of missing EGR.
As this time I spent some more time under the hood, I've made a record of the engine sound. Each and every time there is this click sound, and immediately engine start to shake.
Here is it. Four attempts:
Have you got any idea of what can it be?

 

One suggestion would be to look for vacuum leaks. The internet could guide you with methods to detect vacuum leaks.

 

Hmm, that click kinda sounds like the air conditioner compressor engaging, but that would click on and off periodically. It could also be a relay or solenoid engaging, but it would have to be a heavy duty one to be heard. Where on the engine is it loudest, or appear to be coming from? Does it make any difference on what gear you're in? Do you have the option of disabling the MDS system to see if this affects it at all?

If you think it might be the MDS, adding a quart of Seafoam engine cleaner, or a quart of Marvel Mystery oil might solve the issue. On either, add the quart to the engine oil, drive it easy for about 50 miles or so, then change the oil. If nothing else it'll clean everything out in there.

Beyond that, I'm out of ideas from a thousand miles away.

 

AC and all ventilation are off. The only difference on Drive is that engine vibrations are much stronger when car is stopped. In general it runs pretty normal on higher revs including some speed. After sitting there, listening, and making PhD for so long time I cannot even say if if vibrates on higher rpms more then before the problem occurred.

I forgot to mention that oil has been changed at the very beginning of this story, with usage of BG 109 EPR cleaner.
This engine is V6 thus, I believe, not equipped with MDS.

The sound is more like mechanical one. It really doesn't sound like a relay click, but who knows what happens with a sound running through all those plastic bodies. But for sure this is not AC relay: I turned it on to compare and this it's different sound.

I was suggested to clean camshaft position sensor and try to disconnect MAF and observe results - optionally clean too.
I will, of course, follow DDCREW suggestion to search for vacuum leaks too.

Thank you so far, and I will keep you updated.

 

SOLVED
It was... the screw.
The one which is below VVT phasers and acts as plug at the end of the oil channel. It just fell down.
People in workshop said that I was extremely lucky that this screw haven't done any more damage.
Factory fault they say.