Hi,
Thanks to the advice from Mr Cheerful and rp, I have been trying to follow the vacuum hose from the pump on my 16v 1.4L diesel Citroen c3.
The hose runs from the pump to the brakes via a tee. The other branch runs to a black plastic box on the back of the engine. Whilst the box is not the cause of the leak, I was just wondering what this box is and what it does: can anyone tell me?
The pipe then goes to what I thought was the egr valve. When the garage read my codes they changed the "egr valves" and gave me two objects. These were made of black plastic and are manufacturer by Bosch. There is an electrical connection and two vacuum pipes.
This is what confused me because a citroen dealer and the Haynes book both say there is only one egr valve. Having read the book again, it shows one of the items as "egr solenoid valve", the second one must be a solenoid valve for something else but does anyone know what? It is higher up the back of the engine, almost on the right hand edge of the engine.
I have tested the vacuum at these solenoid valves at on one hose it is
-25 ins Hg and the other hose measures 0. I presume this means that the solenoid is not actuated. Would I be right to think the second hose would drop to -25 if the solenoid was actuated?
There is a metal pipe, about an inch diameter that Haynes calls the EGR pipe. This runs to a circular metal object. One of the hoses runs from the solenoid to this circular object. The hose was fitted so tightly, I could not remove it to test the vacuum here. Is this circular metal thing the "proper" egr valve? Do I need to worry about testing the vacuum here?
Should I be concerned that the vacuum at the solenoids is -25, rather than the -28 at the pump? Somewhere I have lost 3 ins Hg or is this loss nothing to worry about? Clearly my main worry is the subsequent loss of another 15 ins Hg as the vacuum at the turbo waste gate is
-10insHg.
I think the leak must be in the section between the second, unidentified, solenoid and the waste gate so I hope to replace this and see.
On the subject of the metal egr pipe, there was a slight coating of soot. Is a millimetre of carbon anything to worry about or do the problems occur when the pipe is clogged with a more substantial, say
5mm, layer of carbon?I sprayed some carburetor cleaner spray into the pipe and that removed the soot from the end but do I need to pull a rag through to clean the pipe properly?
Thanks very much in advance.