2.7Hdi Coupe looses water and gains water pressure

[PietHenning]

Hello, I'm new here. I own a 2006 Coupe 2.7 Hdi. Great car.
I bought it with 80000 km on the clock. Previous owner received a new engine at 72000 km. They also replaced the front turbo. I have all documents that shows it. The new engine (only main engine) has a warranty of 20000 km and there is still halve of it left. The car is on 85300 km now.
After coming home with the car (I live in Cape Town and bought it in Johannesburg 1450 km away) I noticed oil drops around the back turbo. There is also some oil in the pipe going to the inter-cooler. The cars very smooth and nice and I decided the turbo can wait for my holidays.
One week ago I was driving happily and suddenly saw and heard warnings. The car was overheating. As I pulled of the road the heat gauge dropped towards the middle. I switched off the engine. Opened the bonnet and saw no steam coming from the cap. Started again and saw the heat gauge drop to 70 degC, then rising to 95 and dropping to 85. It seemed the thermostat worked. I got home OK. Next morning I added 2 liter of water and drove it to work. Temperature behaved fine, but after 70km started to run just over 90 degC. After cooling I added 3 liters of water.
I tested for CO2 in the water at the radiator workshop -nothing found.
Testing at home:
I bought a new cap from the dealer just in case. 20 years ago my boiling VW just needed a new cap. Maybe I will be that lucky again
I removed one of the breather pipes on the filling tank and plugged it, then put a rubber pipe into its hole and pumped the tank/system. At 1.4 bar the cap released. This is exactly right. The new cap did the same. I kept the pressure at 1.4 bar and looked for a leak but after 1 hour found nothing.
I fitted the new cap, filled the water and took a test drive. All the time the temp is around 90 degC. After 14 km I stopped to look under the bonnet. I heard the water cap releasing air/steam. Maybe I added too much water.
I drove another 20 km, the same. Drove home another 20 km and the cap still blew of something. I let it cool.
This morning there was still a lot of pressure in the system. I released the air from the cap and added 3 liters of water.
I drove 12 km round trip and found the cap releasing air or steam. Temp was around 90 all the time.
With the engine hot I rigged up my pressure test again. As soon as the pressure reached 1.4 bar the same noise came from the cap that described as releasing air or steam.
With the hot engine I hoped to catch the leak, but nothing.
My thinking:
Why is there pressure in the water system?
If the water was too much, why did the blow-off not stop after dumping the access?
Can it be that the turbo got damaged when the engine blew and it only shows now by having some problem on its cooling side?
If exhaust gas enters the water in the turbo (it is water cooled) there will be CO2 in the water.
If the leak is between water and pressured air in the turbo, the water will leak to the turbo because turbo'd air is less than 1 bar (ca.989 Pa).
I looked in-between the V and cannot see any water leaking from the thermostat housing.
Can a leak be responsible for less pressure and less pressure be the cause that the water makes a lot of steam at 90 degC and that is why the cap bleeds off?

I prefer to find the problem before taking it to Peugeot service department to avoid them spending hours or days looking for the problem on my tab (they are REALLY expensive)
I hope somebody who had a similar problem can tell me where to look and that it is a small problem to fix.
I'm looking forward to your comments and suggestions.
Thanks and regards
Piet Henning
South Africa

[Peter.N.]

Unfortunately I think you will find that the head gasket is leaking, they generally only leak under power as at tickover the pressure is not enough to eject the water. If you put the end of the overflow pipe in a receptical and drive it you will probably find the coolant you have lost will be in it.

Peter

[Trainman]

I would agree with Peter, there is also a dedicated 407 owners forum here: http://www.407owners.com/forums/index.php" onclick="window.open(this.href);return false;

[PietHenning]

Thanks for the answers. I cannot remember hearing the fan come on. Tomorrow I will connect a gadget to the diagnostics and see if there are fault codes. Rgds. Piet

[addo]

If you have the Peugeot Planet diagnostics, or "Diagbox" either system will tell you much more than an everyday OBD reader.

[PietHenning]

My friend has an OBD reader and android app. He owns a coupe as well (2008).

[Gibbo_Wirral]

If you're talking about the Torque app, I've found it very hit and miss on Peugeots.

I've done some tests with various scanners on my car with known EGR, diesel heater sensor, and glow plug faults and only Planet picked up these fault codes and read the live data to show that the parts were indeed faulty.

[PietHenning]

OBD cannot see any fault codes.
I'll have to find a proper diagnostic tool- or do the right thing and take it to the dealer.

[addo]

If you have a little experience with computers, owning the diagnostic gear is a big step ahead of paying the service agents.

[PietHenning]

I already looked at buying Planet 2000. There are several on British ebay and some in China. It seems affordable and wotrh having. Problem for me in South Africa is buying on British ebay. I'm not sure if the Chinese Planet 2000 is the real thing. It is this: http://www.obd2be.com/lexia-3-citroen-p ... p-455.html" onclick="window.open(this.href);return false;

[Hell Razor5543]

The main thing to check is what version of DiagBox (the central software component) the equipment can use. Some of the Chinese clone chipsets have been blacklisted, and can only work with software up to version 5.29. The firmware can be updated, but this does cost (although I do not know how much).

Something else to know is that (if you plan on using it on Citroens) the Lexia software component cannot work directly on a 64bit O/S. You will need to run it on a Virtual Machine with clean access to the USB systems. It will, however, have no issues with a 32bit O/S (an so does not need to be run from within a VM). I do not know if PP2000 has this issue.

[PietHenning]

Thanks James. I will pay more and buy it in Brittan. I have a friend there who can assist. I have an old laptop that runs on XP 32 bit that I will keep just in case.
How can I find out what version my car needs. I have a 2006 (before November) and my friend who will also use it has a 2008.
I do not own a Citroen......yet.

[addo]

The exact details of installation seem to change regularly. If you have some computer help available to install and configure the software it really is the best thing - you will be paying plenty to the Peugeot family each time you replace a specific part, so you are not leaving them penniless.

All the versions offered are unauthorised copies, the more up to date ones like DiagBox simply put a new "skin" on the software for diagnosing older models. Genuine diagnostic kit is dealer only and well into the thousands - nor can you buy the current versions, only out-of-date test gear from bankrupt dealers and that sort of thing.

[Gibbo_Wirral]

I normally recommend buying a Revision C Lexia / Lexia3 cable, and the standard Planet software versions most work to are V22.14, with a patch updating it to V24.29.

For the Diagbox software you should expect V7.02 patched (otherwise you'll have registration and activation problems) with updates to V7.55 (as of 11/14).

I've done several hundred diagnostics with Planet. The only cars it wouldn't work on were oddly my own 307s - a 57 plate 1.6 110bhp HDI and my current 2003 2.0 90bhp HDI. On both it just won't read the Engine ECU. Diagbox 7 works fine though.

[PietHenning]

Update:
I removed the temerature sensor and held it boiling water (kettle actually boiling while connected to power). The temp gauge showed 93 (just under the 95 degC line). I thought this to be a problem because according to documents found the fan starts at 96 degC. I could not find a new sensor from Peugeot. Nothing in all of South Africa. I found a 2nd hand Landrover sensor fro 2.7 TDV6 engine. It did the same as mine.
If I remove the plug from the sensor and start the car all fans blow full force, which means the fans are working, but while driving the fans are not working and they should because the the temp shows up 95 degC on the gauge that I know is showing 7degC less that what it really is. Is there a way to calibrate the sensor?
It still bothers me why the engine blew with the previous owner and if they ever found the real reason. Maybe not and its repeating after 11000 km's.
I plan to buy PP2000 v25. But if the temperature sensor does not know what the temperature is, how can it register a fault?