Couple days ago I clean my 4,4TDV8 intake plenum with EGR pipe and throttle valve (can read about it in my "My Range Rover" post). I wont accept there was also quite dirty further, inside the manifold.
So, today I buy 4 bottles of diesel intake cleaner by Liqui Moly.
Quite expensive liquid, should be good I suppouse. Why 4? Just to be sure its really clean.
Due plenum is already clean, closest "hole" to manifold I found is MAP sensor. Easy to remove MAP as well.
Then just start the engine, get it running at 2000rpm and just spray.
There is the pressure inside the plenum when engine is running at higher rpm, so need to use some seal (check picture).
Of course ECU go to restricted mode soon (due too low boost value), so later need to delete error code.
After all 4 bottles are empty, make test drive with rapid acceleration and high rpm. Yes, there was blue smoke behind the car during test drive. But not very long time.
Done.
But, I cant get no sleep without seeing the result. Tomorrow I will again remove the plenum and check how it looks inside the manifold. And for sure pictures are coming.
Now everyone can predict whether it got clean or not.

I hope that does the job, 4 x cans in the UK is over £100

but if it works then well worth it - please keep us posted


do you have any code errors ( DTC's ) , or "Restricted Performance" showing on the dash ?

Here the same, over 100€. But its much much cheaper than remove the manifold, and even then anywhy can`t clean the channels near valves in the head (only by walnut shell blasting).
Well, we will see tomorrow the result, hope that works.

Yes, "Restricted performance" showing immidietly when add the rpm-s to 2000. But I have iCarsoft, so erase this error easy after work is done.

What actual benefits are there to having a clean intake ? 2012 TDV8 Vogue (L322)

The result.
Iam very, VERY disappointed.
FOUR cans, direct spraing (very close to manifold), 100€ and ZERO result. F**k.
The soot surface was oily and shiny before, now its just matte black, so it dissolve oil a littlebit on the top layer. But deeper its the same oily soot as it was before.
I didn't expect it to be like new after cleaning with this expensive fluid, but I was hoping to see a significant change at least. I was ready to buy even more those cans in case if I see any cleaning effect. But unfortunately no, effect is close to zero.
I dont know how it looks deeper, in channels before valves for example, but I think there is the same result.
Not reccomend, wasted money.

Where the intake narrows the intake velocity will be higher so deposits will be thinner. It's a diesel engine - it's never going to be clean. 2012 TDV8 Vogue (L322)

I'm working on the theory that with my EGR now non-operational that the inlet manifolds will eventually be cleaned by the air now being free of exhaust carbon, but I won't be removing the plenum to check. I will however keep a check on the MAP sensor which should now stay clean.

Can't say I would spray one can in mine, any cleaner must be solvent based, you have sprayed a powerful solvent straight into the engine, this will wash the bores of diesel and remove lubrication in the upper part of the engine, it could also dilute the oil.

If any of these "snake oil" additives work then they would be recommended by the manufacturer, as far as I'm aware, none are...

Just my 2p on the subject..  Pete
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FWIW I had mine Terra Cleaned. I’ve not inspected it since but it does seem more responsive and the mpg has gone up by about 1 mpg ! ( which is 3% ). TDV8 4.4 2012

JayGee:
Yes, in theory it should be like that, but in practice we have lot of examples with fully clogged channels near valves. Especially diesel BMW owners have this kind of issues. Yes, they have additionaly swirl-valves on the way, but still, wouldnt be bad clean once intake and forget about it for long time.

GraemeS and RamblinMan:
Dont need to remove plenum, just release one of four intake short hose between plenum and manifold, and slide it away. There is a gap apr. half cm and you can see littlebit inside the plenum with flashlight.

Haylands:
Yes, solvent wash the lubricant from the cylinder surface, but new diesel injected all the time. Also thatwhy I spray one bottle and then make a test drive. And only then next can.
Oil dillution is very possible, but solvent is well evaporative fluid and it will gone soon from the oil.

Well, the fact is that was quite pointless work and nobody will not do it after my experience I hope (of course I dont know how it looks inside the head now, maybe it even works there due higher air speed, but I dont belive).

Given how quickly the MAP sensor soots up it would seem pointless even if you could clean it...... 2012 TDV8 Vogue (L322)

Here you are right JayGee, I have driven 1000km after plenum chamber cleaning and MAP was also cleaned of course, and in this short distance MAP was littlebit clogged already.
So, what options we have?
1) Delete EGR
or
2) Replace turbocharger every oil change
or
3) Do nothing and just drive untill you finally feel there is no power in engine, or fuel consumption rise, or some fault code appear, or some other consequence...or you JayGee are right about air velocity is higher in channels so deposits will be thinner and never clogge channels enough to disturb proper engine work.

Most people are just driving and clocking up huge mileages with no loss of power or MPG. Just clean the MAP every service and stop worrying about it  2012 TDV8 Vogue (L322)

I’ve used Liqui Moly injector cleaner on my P38 2.5d last year and that worked well.

But, the 4.4 TDV8 is a different beast altogether and commands more respect from me

Well done for trying. But I’ll just keep the MAF sensor clean - that works wonders. 2012 4.4 TDV8 Westminster - Baltic Blue, Jet interior
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