I know the issue of EGR soot buildup has been discussed a lot, in context of specific faults (eg with restricted performance messages, DPF issues, cracked hoses, stuck throttle body etc); but in a more general way, I would be grateful for thoughts as to whether this is something that is worth addressing.

My situation is I recently changed my RR, and got a 2016 L405, 4.4SDV8; and in my first day of ownership it threw up the restricted performance message, and the P006A-84 (manifold absolute pressure), together with P05ED-16 (diesel exhaust fluid heater control unit supply voltage). I cleared both, and checked the MAP sensor which was VERY caked up, so I cleaned it with EGR cleaning fluid. While it was out, it was obvious that the inside of the air intake duct donut was caked in a layer of soot. I tried to vacuum out as much as I could with a drinking straw sealed onto a dyson hose, and have refitted everything. My hope is that there is not something else underlying (cracked hoses, manifold etc), and in the absence of a smoke test this is as far as I am planning to take it for now, unless the error comes back – and the car is under warranty.

But, it got me thinking – from previous FFRRs I’ve had, I know it’s quite common for the insides of the donut (and throttle body) to get caked in soot, due to EGR gases etc. And I don’t want an EGR delete/blank. Also I am not a fan of the often-advocated idea of spraying cleaner in to the air intake whilst it is in place, as I don’t like the idea of any chunks of crud going through the engine.

So, my question is whether it’s ok to allow the inside of the donut to remain coated in a thick layer of caked on soot, or whether it is worth once in a while (say every year or so) removing the donut together with the throttle body, and completely cleaning out the insides with EGR fluid? Or is that overkill/OCD? Or should I follow the “if it aint broke don’t fix it” policy, and assume that this soot buildup is something that JLR anticipated when designing the car, and the car can run happily with it?

Thank you for any thoughts on this. -- .. -.- .
L405 2016 4.4 SDV8 SE
..................................
Evoque 2016 2.0d HSE
L322 2010 4.4 TDV8 SE
Freelander 2 2009 HSE
L405 2015 4.4 SDV8
L322 2005 2.9 TD6
P38 2000 2.5 DSE

There is a full DIY write up on here on how to remove and clean it.
Also, this might help too:


Be very careful with NaOH and water. Add the NaOH to water. Not the reverse. Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
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Thanks Rob, that's a nice video.
Any thoughts about the question of whether this is something that needs done, as a preventative measure, from time to time? Or whether that is overkill, and "if it aint broke don't fix it"? -- .. -.- .
L405 2016 4.4 SDV8 SE
..................................
Evoque 2016 2.0d HSE
L322 2010 4.4 TDV8 SE
Freelander 2 2009 HSE
L405 2015 4.4 SDV8
L322 2005 2.9 TD6
P38 2000 2.5 DSE

if you clean then its bound to improve airflow...and you'll feel better knowing its done..  ... - .- -.




Y. O. L. O.
.

Thank you Stan. Is it something that you do once in a while to your L405, pre-emptively, or only if there is a fault message? -- .. -.- .
L405 2016 4.4 SDV8 SE
..................................
Evoque 2016 2.0d HSE
L322 2010 4.4 TDV8 SE
Freelander 2 2009 HSE
L405 2015 4.4 SDV8
L322 2005 2.9 TD6
P38 2000 2.5 DSE

i dont..i have a clean tdv6  ... - .- -.




Y. O. L. O.
.

Very sensible  -- .. -.- .
L405 2016 4.4 SDV8 SE
..................................
Evoque 2016 2.0d HSE
L322 2010 4.4 TDV8 SE
Freelander 2 2009 HSE
L405 2015 4.4 SDV8
L322 2005 2.9 TD6
P38 2000 2.5 DSE

&ab_channel=RaymiesGarage

Nice find. Thanks. -- .. -.- .
L405 2016 4.4 SDV8 SE
..................................
Evoque 2016 2.0d HSE
L322 2010 4.4 TDV8 SE
Freelander 2 2009 HSE
L405 2015 4.4 SDV8
L322 2005 2.9 TD6
P38 2000 2.5 DSE