Hi,

I have recently purchased a L322 4.4 TDV8.

I removed some of the intercooler pipping between the secondary turbo and the change over valve. I was quite suprised to find the pipe clogged with ice (see pictures). The car have been parked for a while, and last time it was started was before freezing temps. After heating the garage for a couple of days I also removed the elbow from the air box, which also had a some water in it.

Has anyone else come across this "problem"?

My theory is that the water comes from condensation when air is cooled in the intercooler and collects in this intercooler pipe because it is the lowest point on the system. I can't think of any other way water find it's way there (clear water, not coolant). If the car is driven gently and not activating the secondary turbo it can collect over quite some time, and freeze if parked in cold weather.

The water in the elbow from the airbox is more of a mystery to me, even tho the secondary turbo is not activated it would probably spin to some extend and suck the water in. I don't dare to think about what would have happend if the turbo sucked in ice during full acceleration...

On the primary turbo side, everything was completley dry. The car drives perfect, I bought it in Germany and drove 1000 km to Norway before i made this discovery. I drove carefully the whole trip and probably didn't boot it enough to activate both turbos.

I've read that intercooler icing is a issue on some VAG diesel engines, but can't find anything regarding the TDV8.

I have read about the "turbo drain mod" and problems with smoke during heavy acceleration on some 4.4's. Maybe some of this smoke is coming from water and not only oil?

Some drops of water into the engine is probably not a problem, but a large quantity of water or ice when the second turbo activates can't be good..

Sorry for a long post! Not sure what to do about this, and if it even is possible to "fix".

Attaching some pictures so that you believe me:

I can't see how that much water is from condensation, although I suppose it could have collected after a long period of time.

You would think it would get blown out by "normal" driving....

Maybe the water was there before you bought it, I would check for other signs of it being stood in water, damp carpets, wet under the spare wheel etc...

Hope it's an innocent reason it's there....  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

I've been thinking about the same possibilities, but there is no sign of water anywhere else. Both airfilters and airboxes are completly dry and had "dry dust" on the dirty side.

It was raining like crazy on parts of the drive from Germany, maybe the very humid air combined with highway cruising have contributed to the water build up? 2012 Range Rover TDV8 4.4

That's astounding!
I'm curious as to why you started dismantling the pipework. Were you looking for the cause of a performance issue?

I agree!

I've read about the problems with oil build up in the secondary turbo / pipework on the 4.4 and noticed that both the intercooler pipe and airbox "elbow" was wet.

Wanted to see how much oil was in the pipework and drain what was there before I started to regulary boot the car to keep it clean. To my surprise no oil, but ice/water came out.

Car drives perfect, engine runs smoothly and I haven't noticed any smoke. But last time i drove the car it was above freezing temps and probably haven't accelerated hard enough to engage the second turbo in a while

A bit of a mystery! 2012 Range Rover TDV8 4.4

That is a strange one!! 2012 Vogue 4.4 TDV8 - Current
2014 Navara V6 - Gone
2004 Vogue TD6 - Gone
Grand Cherokee - Gone
Discovery V8 (LPG) - Gone
Discovery TD5 - Gone

VAG even issued a revised intercooler for the models that collect water in the IC.
It's an intercooler with water sensor and drain valve.
They (VAG, as far as I understood) say it's because the EGR system dumps low pressure warm & humid air into the intake. Exhaust gas has a fair amount of water as combustion by-product.
They (forum members) also mention 'highmiling' might be a factor, driving as fuel economic as possible. Maybe low air speed with an effective IC can get the air going through it below dewpoint


As far as I know dewpoints:

Click image to enlarge

Way past my pay grade... it is condensation then...?? Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

On these engines the water can't enter via the EGR system as that gas goes directly to the cylinders, not via the IC.

Thank's for your comments!

The graph was a little complicated for me to understand, but I found a calculator that made things a bit easier
(https://www.calculator.net/dew-point-calculator.html)

I think you’re underestimating the outlet temp of the turbo charge air. A very quick google would suggest a typical 15psi turbo outlet could raise the temp of the air to around 100 to 125 degC and a good intercooler will take about 65degC off that, leaving the engine inlet temp around 40 to 50 degC. V8 or else ...

Here https://forums.tdiclub.com/index.php?threa...re.302863/I found this, page 1:

Quote:

Causes
This is a thermodynamic phenomenon caused by condensation and subsequent freezing or direct vapor deposition of water vapor as the turbo-compressed charge air is cooled through the IC and outlet charge hose assembly. Two main aspects of engine design contribute to the problem:

1 - Low-pressure EGR is used to control NOx formation for emissions compliance, however, this recirculates water vapor rich exhaust back to the turbo and IC.
2 - The IC design on these vehicles is very efficient, providing good heat transfer and economy (and good ice formation under proper conditions)

Very specific conditions in those engines.

As mentioned by GraemeS, we (4.4TDV8 people) don't have the low pressure EGR back into the turbo and IC.
We just have turbo compressed & hot air, with whatever water is in it, going through the IC.
The numbers that fisha posted show the IC (our IC?) can't really cool that hot air down to below dew point.
So my guess is condensation is not likely.
If it was the case it would be an issue in every turbo intercooler diesel used in cold climates and it isn't.

The last 3 weeks I've been up north in sub zero C conditions.
The humidity is really low as cold air can't hold much water to begin with (as far as I know it's not even water vapor, it's water in gas state, vapor is already water in liquid state around a tiny dirt particle, sorry for the side step)
To get the last bit of water to condensate one needs to go to a really low temperature.
I doubt our IC can do this.

So... where did all that water come from?
What about a tiny leak in the IC, tiny enough to not upset the ECU detecting turbo pressure loss but big enough to suck in water during long engine braking (vacuum in intake system) situations when it's raining?
I dunno  2012 4.4TDV8
2000 Honda S2000

The reason I was thinking that water build up may be a "issue" on the 4.4 TDV8 is the way the turbo system is designed. As you know the secondary turbo only kicks in when accelerating relativly hard. All other times the compressed air is circulated back into the intake elbow thru the change over valve, it will be a cloosed loop until the valve opens and directs air into the intercooler.

I can't see how boost can build (air compresses) in this process since it's not a closed circuit. When the air is directed back too the intake elbow, which is connectet to the airbox and again out in the open. Maybe the air beeing sucked back into the turbo causes it to be kind of a closed circuit? If the air isn't heated too over the boiling point the water won't evaporate, but maybe heated enough to pass the dew-point? A lot of guesswork from my side

Also when the car is parked if there is any condensation on the inside of the intercooler or elsewhere I was thinking that the water may flow out the "secondary turbo inlet" on the intercooler, thru the change over valve (which probably isn't completly water tight) and down into the pipework which is the lowest point (where I found the ice).

There have been many posts about white/grey smoke from the 4.4 TDV8's when accelerating hard. The answer is usually that the turbo drain mod needs to be done or turbo changed because of bad seals (oil build up over time). Oil burning should produce blue smoke and not white/grey which usually means water, agree? Of course it can be difficult to see the difference in the mirrors. There is also some posts about smoking issues even if the turbo drain mod is completed.

I can add that I've put the car back togheter and it drives perfect and accelerates like a stink! What a car!  2012 Range Rover TDV8 4.4

Blue smoke is only produced when oil is ingested into the engine and burnt in the cylinders. White / grey smoke is vaporized oil accumulating in the exhaust side of the turbo. 2012 TDV8 Vogue (L322)

AdrianL322 wrote:

The reason I was thinking that water build up may be a "issue" on the 4.4 TDV8 is the way the turbo system is designed. As you know the secondary turbo only kicks in when accelerating relativly hard. All other times the compressed air is circulated back into the intake elbow thru the change over valve, it will be a cloosed loop until the valve opens and directs air into the intercooler.

As far as I read & understand:
The sec.turbo doesn't spin at all when it's not needed while driving (below 2400rpm and depending on load).
It has an exhaust shut-off valve stopping exhaust flow into the turbine.
So if you are hipermiling there is no air circulation in that part of the piping.
The recirculating happens in the - very - short time it takes the sec.turbo to spin up and match the pressure from the prim.turbo.
According to the workshop manual this take 180 milliseconds.

After 3 minutes of idling the engine also goes into bi-turbo mode.
IOW the exhaust shut-off valve opens and the sec.turbo spins, at very low rpm I would say.
Whatever flow it then produces goes through the IC, like during normal bi-turbo mode (that's how I understand it)
But when you're not moving the IC doesn't really cool that much, I suppose.
Only the air pulled in by the radiator fan is cooling it. 2012 4.4TDV8
2000 Honda S2000