I work for the NHS in mental health and have recently been asked to support a client who is very experienced in working on cars and is used to dismantling engines, changing head gaskets, etc. He recently bought a 2002 VW Lupo 1.7 SDI on ebay with broken coil springs and rusted front brakes. There are a few areas where we need some advice: 1) The ‘Check Engine’ light is not illuminating when the ignition is switched on, but when you direct a torch onto the dashboard you can clearly see the ‘Check Engine’ icon. Should the engine light on this model illuminate upon switching on the ignition? 2) The EGR valve seems to be disconnected. Is there a reason
for this and why is there a ‘cut’ pipe connected to it? 3) What are the torque settings for the front brake caliper bolts? There are two Torx bolts, a longer upper one and shorter lower one; we renewed them both with a set from Euro Car Parts supplied with a rubber rings and grease. 4. Even after changing the front brakes, the brakes feel very weak.
Is this normal for this model or should we suspect a fault? 5. When we changed the fuel filter, we clamped the fuel pipes and filled the filter with fresh diesel, making sure it was full to the top to minimise the possibility of an air-lock in the system. Having already warmed up the engine before the filter change, we then ran the engine at 2500-3000rpm for a period of time, but air bubbles were still present in the transparent pipe between the filter and fuel pump. We renewed the seals at the fuel connection where some cheap clips were present and the pipes at this connection were left undone and the seals changed with the pipes undisturbed. The remaining two pipes are secured with same type of clip – although they are not loose, we were able to turn them round on their axis after reinstalling the clips, so I’m not sure if they were tight enough. Should we replace the clips on the fuel filter or should we follow some special procedure to bleed the air from the system? Using a basic scanning tool, it shows no error codes.
Yes, the EML should illuminate when the ignition is switched on. I suspect the bulb has been removed to cover the fact that the EGR valve has been disconnected. First, remove the dashboard and see if the bulb is blown or missing. It is strange that no codes are showing on your scanner, but this may be a compatibility issue, as Eobd-compliance didn’t come into force on diesels until 2004.
The EGR valve should be bolted to the inlet manifold and the pipe should go down to the exhaust manifold. The EGR is operated by a vacuum pipe from the EGR control valve on the bulkhead. From your description, it sounds as though the pipe has been disconnected and probably blanked off. This is confirmed in the photo you supplied.
The torque settings for both caliper bolts is 25Nm. It is difficult to comment on the feel of the brakes, but provided the vacuum pump is operating and the brake pedal is neither rock solid or spongy, this may be the standard feel of the brakes. A good test would be to ask your local MOT station to check them on a rolling road; this will give a better idea of the effort being applied and the balance of the system.
Provided the engine starts and runs OK, I would simply replace the clips. An air leak into the fuel system will normally result in poor starting and produce black smoke while driving. Some visible air bubbles in the pipes does not necessarily indicate a serious problem. If there are no running problems, the system should purge itself over time.