Help please, poorly C5

[fastjet]

Hi to everyone. My C5 2.0 Hdi (67000 miles) is some what poorly , could I ask for some help on what might have gone wrong.

There seems to be three symptoms which may or may not be connected.
1. Fuel consumption is up, best I can get is now 40mpg.
2. Does not want to rev freely, ok to about 3000 rpm then the increase in rpm is slow. Seems to lack a surgue in power.
3 When on very light throttle or when coming of the throttle, there is a strange noise which sounds like a deep bird chirp. This tends to occure around 1500 rpm. If you go on and off the throttle between 1500 - 2000 rpm you can all most play a tune. The noise last for a few seconds.

All advice would be really helpful.

Thank you.

[GiveMeABreak]

We don't know what year you have or engine - a VIN would help.

A diagnostic on a Lexia is really needed to determine what it is not happy about, but if you have a loss of power, a shrieking noise and any excess smoke then it may eb a sign of turbo failure or turbo-related. BUT, until you get it on a Lexia that is just speculation. You may just have a leak in the turbo hose for example, so bet get it diagnosed and report back on the codes, if any.

[fastjet]

Hi it is a 2004 mk1 2.0 Hdi. No smoke or shrieking noises.
When on very light throttle or when coming of the throttle, there is a strange noise which sounds like a deep bird chirp. This tends to occur around 1500 rpm. If you go on and off the throttle between 1500 - 2000 rpm you can all most play a tune. The noise last just for a few seconds.
vin - VF7**************[VIN obfuscated, can be read by forum staff]

[fastjet]

Hi.

Is the egr valve connected to the cooling system? If so, when removed can I expect a small amount of coolant loss or a fair amount.
Thanks

[GiveMeABreak]

No nothing to do with the cooling system. The EGR recycles hot exhaust gases back into the cylinder to aid in reaching operating temperature more quickly and to help reduce emissions.

So you have the DW10ATED 2.0 HDi 110 engine.

[DHallworth]

Interestingly, the EGR valves on the V6 HDi's are connected to the cooling system

David.

[GiveMeABreak]

Of course the EGR cooling circuit had a dozen other things going on David

I’ll try and look something up tomorrow when on Deep Blue.

[GiveMeABreak]

Right now I'm back in the zone, here is the procedure for removing the EGR Valve and Heat Exchanger:

Drain the cooling system.
Disconnect the battery negative terminal.

Removing

Disconnect the connector (1) Remove: The air cleaner (3) The flow meter (2)	Disconnect the hose at "a". Remove: The nut (5) The nut (6) The bolts (4)

• Disconnect the EGR valve hose at " b".
• Lift the heat exchanger EGR valve assembly

(Note: Retrieve the seal 'C')

• Slide the assembly towards the gearbox.
• Disconnect the hose at " d".
• Remove the EGR valve assembly and the exchanger.
• On the work bench, mark the position of the component to be removed.
• Remove the collar ( 7) or (8).

Refitting

• Relocate the unit removed in accordance with the identification marks made before refitting.
• Refit the clip ( 7) or (8).
• Continue the fitting operations in the reverse order to removal.
• Fill and bleed the cooling system

[Gibbo2286]

Before you get into the EGR removing I suggest you double check the vacuum hosing to the turbo etc. the noise you're hearing might be just a hole in one of the hoses (a bit like putting a leaf between your thumbs and blowing through it).

If you've lost the turbo boost through a vacuum leak it will give the power loss symptoms you're experiencing.

[GiveMeABreak]

Yes, I agree and mentioned air leaks in my first post, but we really need a diagnostic code - or you may be undertaking unnecessary work.

[fastjet]

Hi, a big thank you Marc for your help and the info supplied. Thank you Gibbo 2286 for your input too.
I will have a look this weekend, if it stops raining long enough.
Thanks

[GiveMeABreak]

No problems - but I omitted to include 'Drain the Cooling System' first! - So post edited to include that crucial bit of the operation.

[fastjet]

Hi could I ask for help and advice again?
I disconnected the vacuum pipe from the egr valve today and found a couple of interesting points.
There is a vacuum on the egr valve pipe on tick over, is this correct? I would have expected no vacuum at low rpm.
I sealed up the vacuum pipe and took the car for a drive to see what would happen.
Interestingly the mpg was increased by around 5mpg, the chirping noise was more pronounced and lasts much longer, the noise is there between 1500 - 2000 rpm and does not disappear in that rev range.
When I got back home I followed the vacuum pipe across the bulk head, removing the black plastic cover exposes two parts that look like electric solenoid valves, attached photo. Both of these were hot to touch.
Does anyone know if they do get hot and can they become noisy? Also can any explain what they do in the system as they appear to have interconnecting vacuum pipes.
Hope this makes sense.
Thanks

[GiveMeABreak]

These are the recommended checks: You'll need some way to test the pressure though - similar to the tool shown (1) further down. Note the colour of the connectors to identify the relevant electrovalve discussed. Your image is identical to the first diagram below - you can see the coil of the pipes.

(1) Throttle butterfly housing . (2) EGR valve (tube marked in blue). (3) Solenoid valve (black connector). (4) Solenoid valve (blue connector).

EGR Solenoid Valve
A vacuum check is to be carried out between the electrovalve (4) and the EGR valve (2).

• Connect the pressure measuring tool as an adaptor between the electrovalve (4) and the EGR valve (2).
• Compare the values read with those of the table below.

Engine Speed	Vacuum Value
780 rpm 0,5 bar	2500 rpm 0 bar

Butterfly Housing Electrovalve

Check to be effected with all the gases evacuated between the solenoid valve (3) and the throttle housing (1).

• Connect the tool [1] as an adaptor between the electrovalve (3) and the butterfly housing (1).
• Compare the values read with those of the table below.

Engine Speed	Vacuum Value
780 rpm 0,5 bar	2500 rpm 0 bar

EGR Valve

Connect the tool [1] on the EGR valve capsule take-off (2). Apply a vacuum of approx. 0,6 bar(s) to actuate the EGR valve. When the vacuum is suddenly cut off, the valve should click as it returns to its seat. Repeat the operation several times.

Throttle Butterfly Housing

Remove the air duct between the air/air exchanger and the butterfly housing (1). Connect the tool [1] on the butterfly housing vacuum capsule (1). Apply a vacuum of approx. 0,8 bar, the flap (a) of the butterfly housing (1) should be closed.

[Gibbo2286]

I think you need to show the turbo vacuum set up too Marc. it's quite likely that the fault is on that run of hose.