THP engine - Westgate vacuum reservoir line routing

[lancia58]

Hi

In a THP engine the turbo Westgate is switched on and off by a vacuum line ( output of the vacuum pump ) that goes trough a solenoid that can block/let the vacuum to the Westgate. On top of the solenoid there is a vacuum reservoir. Does the vacuum pump line connected to the vacuum reservoir input and the output of the vacuum reservoir is connected to the solenoid , or does the vacuum pump connects to the solenoid input and the solenoid output connected to the vacuum reservoir input and the vacuum reservoir output to the west gate.
Regarding to the solenoid does it matter to which of it's connections ( but the breather ) is input or output ? It is written on one of the connection VAC and on the other OUT but is it blocks or pass the vacuum I just wonder if it is really matter ?

Thanks

[GiveMeABreak]

This diagram shows the correct connections for the system on your C4:

Air circulation (as per arrows):
A: Air
B: Exhaust gas

Key

(1) Vacuum pump.
(2) Vacuum reservoir.
(3) Turbocharger pressure regulation electrovalve.
(4) Boost pressure waste gate (Open at rest).
(5) Exhaust turbine.
(6) Turbocharger cooling electric coolant pump.
(7) Air inlet turbine.
(8) Air cleaner.
(9) Turbine discharge electrovalve .
(10) Right-hand fan (VASC).
(11) Air/air heat exchanger.
(12) Turbocharger excess pressure sensor.
(13) atmospheric pressure sensor.
(14) injection ECU.
(15) Motorised throttle housing .
(16) Sensor for inlet manifold pressure and temperature.
(17) Air inlet manifold.
(18) Engine.
(19) Exhaust gas manifold.
(20) Inlet camshaft dephaser (VVT).
(21) Solenoid valve controlling the camshaft dephaser.

[lancia58]

Marc,

Thanks for the information. Do you know if the vacuum reservoir connections ( two ) one is input and one is output or it doesn't matter which is which ? Same question is for the electro valve ( part 3 ) although it is written on one of the terminals VAC and on the second OUT - just curious because it just blocks or enables the vacuum pass to the waste gate so what's the point in marking the terminals as VAC and OUT ?

Thanks

[GiveMeABreak]

I would connect them the same way as shown as one connection is to the source of the vacuum and the other is to control the wastegate (in the diagram above) as needed by the engine ECU.

[xantia_v6]

The control valve is not just on/off it regulates the pressure to the wastegate actuator so that the wastegate is opened the correct amount to obtain the desired boost pressure. It is important that the soenoid valve is connected correctly.

[mustang]

Dear friends ,where exactly is the location of the vaccum resvoir in thp engine?

[GiveMeABreak]

The vacuum pump is mounted at the end of the exhaust camshaft and there should a pipe to the vacuum reserve from there.

In the diagram above:
Pipe (7) goes to the cylinder head cover breather.
Pipe (6) goes to the turbocharging pressure regulation solenoid valve.
Pipe (5) goes to the vacuum reserve.

[lancia58]

Hi,

Below is a photo of the vacuum reservoir. There are two terminals ( closed with the Red caps ). None of the terminals is marked as input or output. To which of the terminals the vacuum pump is hooked to , and which terminal goes to the solenoid valve ? It the terminals are not marked it may be that both can serve as input or output ?

[lancia58]

Hi,

I talked with a mechanics who work in an authorized Citroen garage. He told me that each of the terminals of the vacuum reservoir can serve as input or output.

Thanks
Zohar

[GiveMeABreak]

These electrovalves can be different depending on application and can different internal operations - so without knowing the particular ones you have, I just suggested you follow the guide - but at least you know for this particular application.

[Old Nick]

Hi everyone, I know this engine causes a bit of unhappiness with some, but I’m ok with it and just after just after a bit of knowledge and quick advice, please, so I reopen this thread rather than starting a new one

Referring to «Pipe (7) goes to the cylinder head cover breather.», what does this pipe do?

Mine is broken off at the cylinder head cover: Could it cause the wastegate to operate incorrectly?

What wold you suggest as the temporary fix?

Best regards, Nils S

[xantia_v6]

Pipe 7 is the atmospheric port of the valve, it is clipped to the engine cover, but not plumbed in to it.
There should be a small foam filter in a rubber sleeve at the upper end.

[Old Nick]

Hi xantia_v6, thank you so much for the response. Exactly right an what I could not see. I thought was another bit of broken plastic, now I know it is in order. The end is just shieldes by the rocker cover, not attached.