2002 Omega 2.2 DTi Estate – Diesel Y22DTH
Hello
After an MOT back in October I began to suffer from the management light coming on, car into limp mode, and then OK(ish) above about 2000rev. I took it back to the garage; they checked, found an error code and replaced the EGR valve. Turned out the problem wasn’t fixed so they messed about a bit then told me it was then the boost gate. Because of lockdown I couldn’t go long distances and as all the local roads are now 20MPH zones I decided to temporally live with it rather than keep replacing components.
Having trawled through this wonderful group I’m now pretty sure it’s the dreaded leaky vacuum system issue seemingly caused by perished rubber connectors, I eventually found some spare rare & expensive rubber elbows and straights in Turkey (unfortunately before I discovered the post about using very cheap and abundant silicon tubing instead) and replaced a few obvious contenders – no real change. So I printed out the best suggestions on the forum about the issue (see below) and last week took those print-outs and spares back to the garage; again they had no luck and gave up. I suspect that back in October they pulled a few pipes apart and failed to put things back correctly, as there are no decent schematics of the system I’m not that surprised.
I’ve read reports on here (but can’t seem find them now) that some wise guru mechanics have cured the infuriating problem for fellow members; does anyone know where I can find someone around south west London (or further afield as I can get up to 50mph on the motorway) who could help me. Obviously I expect to pay for the service.
Advice gathered from The Forum:-
“…Bottom line is that these diesel setups are simple.
A very useful diag. tool is a Gunsons Lo-Gauge, this allows you to measure the vac in the system be it pre or post actuator valve. You can also use the 'suck' method to test things by sucking on certain pipes to ensure the actuators operate.
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« Reply #39 on: 15 September 2013, 14:51:57 »
Best way to test the vacuum system is with a vacuum gauge. It should read at least 25 inches. Flick / wobble all the rubber connectors. Any drop in the vacuum reading when you disturb a rubber connector means its split or perished. The U shaped vacuum bridge at the back of the head in particular suffers from the heat and perishes or collapses, which is critical because it supplies everything other than the brake servo and causes all sorts of nasties.
The turbo is a variable geometry unit, so it doesn't need a wastegate. The device the vacuum pipe feeds is to adjust the vanes. With vacuum applied the vanes are fully extended, this is the normal operating condition at idle. When the boost sensor towards the back of the inlet manifold senses the boost approaching 2 bar, the vacuum is cut off, the vanes retract and boost is controlled.
Also, in the event of the ECU (or EDC) picking up a critical malfunction, limp mode is activated, one feature of this is that the boost solenoid is deactivated the turbo actuator gets no vacuum so boost is inhibited.
Are you getting vacuum to the turbo actuator at idle? You should see the actuator pull towards the driver’s side of the car upon starting the engine?
« Reply #40 on: 15 September 2013, 14:57:39 »
P.S. The 2 vacuum pipes that disappear into the car, one comes from the vacuum reservoir on the pollen filter housing, feeds into the car as a vacuum feed for the air recurculator valve for the climate, and the other comes back out of the same grommet and feeds the heater bypass valve below the exhaust.
So, the vacuum system is split 3 ways. The brake servo, the climate control feed, and the engine systems feed. Hence the need for 2 reservoirs.”
Many thanks for any help