EGR valve v new turbo

[admiral51]

Okay i understand the replies and the logic behind them but something i had not seen was the fact the vehicle failed to achieve 40 mph.If we accept the mechanics view point that it was the Turbo at fault, that it was over boosting not under boosting, and the OP has already stated there were issues with the Cruise control prior to the Turbo failure, what explains the symptoms the OP is now having.
We know the Turbo was replaced, along with the actuator already preset, and the oil feed pipe replaced.
Oil is dripping onto the Actuator, the feed pipe is directly above the Actuator and is known to be a pig to seal correctly.
EGR replaced, previous fault cleared, now 2 new fault codes, neither directly related to the EGR but vacuum/air flow related and 1 of them being Turbo under boost.

I never replaced the Turbo on my old 1.6 Devil Car, even though i was told it was knackered.
I also could not get it to go past 30-40 mph on occasions, sometimes for a few seconds it would just flat spot, foot flat to the floor no power, lift off and it would pick up.
It happened a few times and cleared itself and never happened again for maybe a few months then again nothing for a month or so. Finally it would give me nothing more often than not,scary to try and pull away from a roundabout, hence the start of the Devil Car thread.
Air Doser was sticking and replaced, as was the Turbo solenoid sensor took a good few weeks to pinpoint the problems, trial and error.

Oil starvation that was originally diagnosed as the cause for the original Turbo failure should not now put up faults relating to under boost/ air flow implausible.

Benscab how sure are you that the Turbo was over boosting to start with, the fact one can fail and the replacement show under boosting just does not make sense

Not trying to confuse the thread, just saying what i have experienced with the 1.6 HDI Turbo issues, and we are all including the OP accepting that the Turbo failed because of oil starvation, when we only have the say so from the mechanic that it failed because of it.

[Benscab123]

I repeatedly got fault code P0234 turbo overboost condition, usually happened on a motorway at speed.

[admiral51]

So if we assume the replacement Turbo is ok, then the fault lies somewhere in the vacuum circuit for under boost ?
I am no mechanic just trying to work through things logically.
Maybe try putting a Vacuum gauge on the pipe to the actuator and see if it holds the vacuum, may have a small leak that cannot be seen by the eye ?
Just trying to help

[Benscab123]

I’m wondering if there is a blockage in the pipework to or from the EGR valve ? Could this cause the turbo underboost ? The car had a replacement EGR (used). The original one gave an excessive flow fault, but as soon as it was replaced I got an insufficient flow fault .................. strange or what ?

[Benscab123]

Could you tell me the part number for the electro valve please Marc , and whereabouts it’s located on the vehicle?

[GiveMeABreak]

Part number is: 1618NR Item (1) below:

To get to it you'll need to remove the upper air intake hoses and the Fuel Filter. Always replace seals with new ones.

Disconnect the battery following the procedure:

BSI Reset / Battery Disconnect / Reconnect Procedure

Remove and move aside the brake fluid reservoir (1). Remove: The air union (2) The air union (3) CAUTION: Cover the openings of the air inlet circuit.	Unclip and move aside the manual priming pump ( 4). Move aside the manual diesel priming pump support. Disconnect the connector (at "a"). Remove: The 3 bolts (5) The cover (6) fitted with the air flow sensor

Remove: The air cleaner (7) The bracket (9) Unclip the components (8), (10) (at "b"). Separate and remove the components (8), (10).	Disconnect the connector (at "c"). Clean the unions (6), (7) using SODIMAC degreasing solution. Uncouple the connectors (6), (7). CAUTION: Plug the openings when a union is uncoupled, using a plug kit. Close the pipes on the fuel filter using a plug kit. Unclip and lift the fuel filter (at "b"). Disconnect the connector (at "d") (According to equipment). Uncouple the fuel bleed pipe - close using a plug kit. Remove the fuel filter (8) (following the arrow ).
Remove: The 3 bolts (2) The fuel filter support (1)	Disconnect the connector (at "a"). Remove: The "CLIC" clip ( 4), using circlip pliers. The 2 bolts (5) The EGR electrovalve (3) Seal

[Benscab123]

I'll just add a further thing here as simple as I can.

The only other thing I can think of with the Turbo is the vacuum circuit. The electrovalve number (5) in the circuit below.

You've already identified oil - that may be the oil lubrication pipe not fitting properly (or wrong part supplied) or the seals. But I though to mention that if the vacuum circuit is not providing sufficient air, or the filter on the electrovalve is blocked - that can affect the operation of the Turbo.



Key:
A: External pipe.
B: Duct internal to the engine.
C: Air.
D: Exhaust.

Reference	Designation
a	Coolant Inlet
b	Coolant Outlet
(1)	Exhaust Gas Recycling (EGR) Regulation Electrovalve
(2)	Air Cleaner
(3)	Air Flow Meter - Air Temperature Sensor
(4)	Vacuum Reservoir
(5)	Turbocharging Pressure Regulation Solenoid Valve
(6)	Exhaust Gas Manifold
(7)	Catalytic Converter - Particle Filter (FAP)
(8)	Air/Air Heat Exchanger
(9)	Butterfly Double Air Metering Device
(10)	Exhaust gas recycling (EGR) Heat Exchanger
(11)	Air Inlet Manifold
(12)	Turbocharger

Sorry Marc I think I may have asked for the wrong part , what I meant was the part (number 5 in your diagram).

[GiveMeABreak]

Ok, no worries at least you have a guide now on how to replace the EGR in future if needed

The Turbo Solenoid is part number: 9652997580 (Pierburg). They are currently £61.08 inc. VAT from Citroen for an OEM quality one.

[admiral51]

If it is in the same location as mine was if you look at the engine from the front of the car,taking the middle of the windscreen as 12 o clock then approx 11 o clock will be about the right area.
It is hidden on the back of the block, difficult to see from both on top and underneath. I clambered onto the engine bay with a torch to finally find it.
The pipes need to reconnected in the same positions, it is important.
Hope you get it sorted

[Benscab123]

Thankyou both

[Benscab123]

I’m still getting insufficient flow fault code even after fitting a brand new EGR valve. Can anyone tell me what else to try please ?

[GiveMeABreak]

If i have read the diagram correctly item #9 is the air doser, the double butterfly valve that i had on my old C5 now with Mike T( not sure if you have the Vin for that still Marc)
If the air doser butterfly valves are sticking could it cause the fault P0401 ie it works most of the time but when it sticks it could allow more/less air than expected ?
I still think the main issue is #5 the solenoid valve, once that is sorted i think it should be easier to narrow down other issues

Here is the function of the Air Dosser on this engine for reference:
Butterfly double air metering device (26) and (27)

Functions of the double butterfly air meter:

• Exhaust gas recycling (EGR)
• Help in particle filter regeneration (FAP)
• Stopping the engine

Reference	Designation
g	Turbocharged air (hot air)
h	Output: Turbocharged air to the air/air heat exchanger
j	Input: Turbocharged air cooled by the air/air heat exchanger
(24)	Inlet air temperature sensor
(25)	Inlet air pressure sensor
(26)	Inlet air heater throttle (hot air meter)
(27)	"EGR" throttle (cold air meter)

As for the Turbo Pressure regulation Solenoid, the regulating electrovalve controls the boost pressure waste gate.

Role of the boost pressure regulating electrovalve:

• Regulate the boost pressure
• To limit the boost pressure

Regulation of the boost pressure is progressive and is controlled by mapping (injection ECU).

As for the specifics of the Turbo Pressure Regulation Solenoid:

(30) Electrical connector.
k: Pressure drop inlet for the vacuum pump.
l: "user" outlet.
m: White marking.

N.B.: The white marking indicates the outlet aperture for the turbocharger regulation control.

The solenoid control is an OCR (Opening Cyclical Ratio) type control.
The proportional electrovalve controlled by an OCR voltage is connected to the following components:

• Atmospheric pressure
• Vacuum supplied by the vacuum pump

The pressure supplied by the electrovalve is included between the atmospheric pressure and the vacuum pump vacuum.

Electrical special features

Features of the OCR signal:

• Supply voltage: 12,5 Volts
• Frequency: 140 Hz
• Fixed period: 7 ms
• Resistance at 20 °C: 15,5 ± 0,7 ohms
• Maximum vacuum: 800 mbars

E: Depression in m.bar.
F: Open cycle ratio (OCR) (in %).
G: Time (ms).
V: Voltage In volts.
T: Fixed period 7 ms or 140 Hz.
Ton: Variable time.
The open cycle ratio (OCR) is determined by the ratio of the variable time ( Ton) to the fixed period (T).
% OCR = (Ton/T) x 100.

The mean voltage (Tm) supplies the turbo pressure regulation electrovalve (1233):

• The greater the OCR percentage, the higher the mean voltage (T1)
• The smaller the OCR percentage, the lower the mean voltage (T2)

Variable voltage control (OCR):

• Full supply (maximum OCR) = Maximum vacuum (800 mbars)
• No supply (minimum OCR) = No vacuum (atmospheric pressure)

[Benscab123]

Does this mean anything to anyone ? I know it’s not Lexia, but it’s all I have at the moment.

[RichardW]

That's not being too helpful - you really need to get it on Diagbox so you can see what the live flows are, and what the reference flows are, and also check the outputs and positions of the relevant sensors and how they are behaving.

[Benscab123]

Yeah I thought as much, I’ll try get it on diagnostic in the next few days. Do I need the data to show the instance the underboost occurs ?