[quote="GraemeS"][quote="Kevhdkent"]

Caesium wrote:

Kevhdkent wrote:

The purpose of this exercise is I’m trying to understand the conditions that caused a critical drop in power while motoring at speed, reducing revs to 500rpm but without stalling the motor. Then complete non-starter, UNTIL the EGR to intake manifolds were disconnected ?

Could the EGR’s fail to open at speed ? Could this cause both lack of power at 60mph, and then refusal to start ?
Starting only occurring when clean air is allowed direct into the manifold ?

Disconnecting the EGR intakes gave exhaust gas somewhere to go which then allowed the engine to fire, indicating that the exhaust was effectively entirely blocked indicating a stuck turbo, nothing to do with EGRs.

There is no waste gate - the turbo is variable vane.

The waste gate is only open under boost ( overboost) so won't be a bypass route around a seized turbo. Can you pull the intake hose of the turbo inlet and see if you can spin the blades? 2012 TDV8 Vogue (L322)

Kevhdkent wrote:

The purpose of this exercise is I’m trying to understand the conditions that caused a critical drop in power while motoring at speed, reducing revs to 500rpm but without stalling the motor. Then complete non-starter, UNTIL the EGR to intake manifolds were disconnected ?

Thanks Mikey, that’s what I wanted to know.

The purpose of this thread and the reason I started a separate one is that I want to understand the reasoning and mechanics behind the issue rather than simply accepting (very welcome) advice.
I guess that’s why most people are on this part of the forum instead of just giving their car straight to a dealer.
I’m just in the early stages with a very low knowledge base !

apologies for resurrecting an old thread but like Kevhdkent all those years ago , I'm trying to get my head around EGR valve operation.

I have an L405 TDV6 mono turbo and having gone through the DPF regen saga I seem to have regens off to a fine art using the famous Kot kit. However looking at the EGR valves, demanded and actual position the B valve does more or less what it's supposed to but the A one is all over the place . It would seem that the valves should be 10% open at the start of a regen but the A valve goes straight to 90% and most of the time it indicates a 100% error. I've double checked the numbers using Icarsoft and get the same readings. Everything seems to work as it should and no alarms.

I mentioned it to my local indie and he seemed to think there was nothing to worry about

Is my understanding of what they should do correct, or should I be worried?
Thanks for looking.