Vectra 2002 dti valve and loss of power? - jocole

I have a Vectra 2002 DTI and it is causing me horrendous problems as my garage, nor Vauxhall seem to be able to fix the problem.

The engine management light comes on (orange) and it goes into 'limp mode' ie looses power. Thi was tested on machine and a fault came up showing 2 sensors, they have been changed but the problem is still there. Next it was put on the machine again and a fault for the vacuum valve came up, this has been changed (at over £150) and still made no difference!

I have asked about the flow meter but they say no fault for that. I have now ordered a valve on the manifold cos told it was that and vauxhall dont sell the valve seperate to the manifold. i dont need a manifold but there you go. that part arrived today, put it on and seems to now be worse than ever? but this fault came up on the machine ??

Please can anyone help? my bill is just over £900.00 so far and im a taxi driver so really need it sorted ASAP!!??

Vectra 2002 dti valve and loss of power? - David G.I.Davies
These systems are dependent on a large amount of rather delicate vacuum tubing and rubber connections and a leak in any part of it wil throw you into limp mode.You have EGR control,turbo control,inlet manifold runner control and heater control vacuum pipes all running to their respective solenoids and connecting back to the vacuum pump on the cylinder head left hand side.I would suggest you check every inch of this black plastic pipework with a magnifying glass! Do not omit the pipe which runs into the bulkhead area and connects to a vacuum reservoir(this is hidden by plastic covering).You might also bear in mind that vacuum pumps frequently fail because the engine is run low on oil,so this needs checking too.
David Davies
Vectra 2002 dti valve and loss of power? - wemyss
Ask them to check that the CAT isnt partially blocked. Thats what it turned out to be on my own Vectra.
Management light on, limp home mode every time I went out.
Cost a small fortune before they found it.
Vectra 2002 dti valve and loss of power? - jocole
Thanks Guys,

I spent 3 hours in the garage last night, tring various things with my mechanic. He has now fitted an Air flow meter, just in case it wasnt working, he reckons it helped, im not sure?! when we put the new manifold valve on the car doesnt run at all and wont go over 4,000 revs!! ??? so that indicates it's causing too much power/pressure and theres a problem elsewhere maybe? that has now been taken off again. I am at my whits end with this. Vauxhall told him yest they cant help and dont know! what? they built the car why dont they know the problem? they said had a 2002 same engine they never could fix and it had to be sold at auction for under £2,000 im gutted - what happens if you cant fix an engine, can it be written off?? is it worth asking my insurer ??

W - what year engine was your Vectra ???

Thanks, Jo

Vectra 2002 dti valve and loss of power? - wemyss
jocole..It is a 1998 Vectra TDI with only 30k on the clock. Long story but main agent had it for three days and couldnt find out why it was going into limp home mode and no power. The code reader told them it was the turbo which tthey duly changed and it made no difference. Every sensor was checked and to quote "came within VX parameters."
They eventually gave up and took it to another main sister VX agent,
They after another two days eventually found the CAT had become partially blocked by dropping the exhaust manifold and the engine would suddenly rev right up....
They said it was something they had never found before and were mystified why a CAT with such low mileage should collapse internally.
It was worked on for a week before they cured the problem.
As said previously it was a long story and my very good local independant had it before them and was getting different code readings and advised a main agent.
Ask them to disconnect the exhaust and see if it makes any difference.
Andrew Moorey (mobile tuning man)on this site and helicoptor (I think) also had a similar experience.
A forum search on this site should tell you the story.
Vectra 2002 dti valve and loss of power? - Screwloose

Re-read and inwardly digest the wise words of David Davies; particularly the section about failed vacuum pumps. Faults like this are found by solid, systematic, diagnosis - not "credit-card fixes." The first [and immutable] rule of diagnosis is "Amass all available information." This must include; a full fault occurrence description; ECU-provided fault-codes and live-data; and both electrical and manual test results. [After many hours of hair-tearing; nasty surprises from fresh information, you can do without.]

It's the work of a few minutes to establish the vacuum level available to the control solenoids. An absolute minimum of 21 inches of Mercury is required. What were the "2 sensors and the vacuum valve" that were changed? Is there a reliable signal from the crank position sensor?
Vectra 2002 dti valve and loss of power? - jocole
Thanks again,

Every code that came up on the vauxhall and my mechanics computer has been changed. I have been down the garage again this morn and we have taken off the new air flow meter, as i dont think there was anything wrong with my old one! def a problem with the valve on manifold, but as i say, cant put it on - too much pressure. Weve double checked all the cables/pipes and now all that is left to try is the crank sensor/valve, but no fault code came up for that one?

The other sensors were on the right hand side of the engine, not sure exact names, but they both had fault codes.....

My mech is considering going back to vauxhall dealer, but is there any point????

Vectra 2002 dti valve and loss of power? - Screwloose

Faultcodes are only guidance; not component replacement instructions - particularly on Vauxhalls. All sorts of codes can often come up from an underlying fault - even a mechanical one. None of the listed components are necessarily faulty; a GM ECU often thrashes about posting false codes, almost at random. That's why it's important to fully understand - and thoroughly test - the system you're fixing before ordering any parts.

This valve on the manifold. If this is a Vectra-B [not the current model] then that's likely to be the EGR valve. [Vectra-C's have an electronic one.] So where does this wild assumption about it causing "too much pressure" come from? Too much pressure in what? Excess inlet pressure is firstly a turbo-boost control matter; then an EGR one. [Code P0400 on these does have a sub-code covering dumping excess inlet pressure via the EGR under certain conditions; but that is usually a vacuum-control issue too.]

Has your garage [who sound very naive at diagnostics] checked that all-important vacuum level - and if so, what was it?
Vectra 2002 dti valve and loss of power? - jocole
Hi again,

Not sure if theyve tested the vacuum level? ill ask. Yes it was the EGR valve - when it was put on (new one) the car then wouldnt even drive out the garage. My mechanic said it was probably cos theres a fault elsewhere and too much pressure was stopping the car going ????

Think its gonna have to go back to vauhxall, sadly they arent v helpful either - just damned expensive :-(
Vectra 2002 dti valve and loss of power? - wemyss
It all sounds very similar to my experience jo. When you go into the Vauxhall agent ask them to check if the CAT is partially blocked.
Vectra 2002 dti valve and loss of power? - jocole
Thanks Wmyss,

Its going back to vauxhall on Tues (great!!) so i will. i mentioned it to my mechanic though and he thought it would be even worse if cat was blocked??

Vectra 2002 dti valve and loss of power? - helicopter
Jo - As Wemyss says, definitely sounds like the same problem as I had with my company Vectra DTI. Intermittent faults, light come on and all sorts of codes of items needing replacement.

I was fed up throwing money at the car , replacing bits that might cure the problem and I decided to use Andrew Moorey , a good friend of this forum who lives locallly to me to go over the whole vacuum system with the result that after two hours of checking everything he discovered the blocked catalytic converter.

The thread that reported this was lost in a backroom meltdown a while back.

You should be able to check the cat by shaking it - if you get a noise like broken glass chinking then the internals have collapsed and are moving causing the intermittent blockages that give you the problem.

I hope you get the problem cured . I was amazed at the difference when the cat was replaced

Vectra 2002 dti valve and loss of power? - gbn
I had the same on a 120k Vectra 2.0 Di

From advice on this forum I checked all the vacuum tubing.
The pipe for the turbo waste gate was mis-routed and had melted shut, ergo bo turbo waste gate.

Ask Honest John

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