Engine Performance problem
2005 Vauxhall Zafira 4 cyl Two Wheel Drive Manual 38000 miles
I have a Zafira B 120 1.9 CDTi (55 reg. Z19DT engine) and, between 2000 and 3000 rpm, I experience an intermittent swooshing sound accompanied by a loss of power. This happens in all gears, but is especially noticeable in 1st and 2nd, and only if I am gently accelerating through 2000 rpm. It swooshes about twice a second and the power loss matches the swooshes, so I get a kind of "kangaroo hop" type of power delivery. If I accelerate harder, it disappears. If I get to 3000 rpm, it disappears. Apart from that, it's a fabulous drive. Sometimes it doesn't "hop" between 2000 and 3000 rpm, and smoothly purrs on through. About half the time, it hops. It is also more noticeable once the engine has warmed up, and much more when going uphill. Rolling road could not reproduce the fault, just real driving.
I took it to a VX dealership and their diagnostics couldn't fault it, despite experiencing the hopping themselves on a test drive. They charged me Ã‚ £46 for this half an hour test and then told me that a further couple of hours diagnosis would be required @ Ã‚ £194 inc. VAT to try to find the problem. They said it wasn't the EGR valve sticking as this wouldn't hop, just give a solid loss of power (famous EGR problem - changed for a brand new VX EGR and it still happens). They also said it wasn't the injector wiring loom (famous 3rd injector problem - I changed the wiring and it still happens). I am at a loss and I don't want to give them any more money for them to tell me a pack of lies about what needs replacing for their own financial gain.
To help with diagnosis, here are some pictures of the engine. They are 3 MB a piece, so they are on my site. Here are links to each one :-
1) Picture of engine from front of car after opening bonnet and removing Ecotec cover :-
2) Zoomed view of injector wiring loom. Which one is the 3rd injector? Is that from the left or right on this engine?
3) Engine sticker showing exact credentials. To the right of this label is a connector not conneted to anything. Is this something to worry about?
4) Tubes down the front right of the engine as I'm looking at it :-
5) Device sitting to the left of the EGR. What is it?
6) Device sitting beyond the EGR (towards the back of the engine as I'm looking at it). The blue clip is loose and needed pressing back in. Made no difference. What is this?
7) Disconnected plug of some sort on the left of the engine. What is this? Does it need connecting?
Has anyone out there any idea what could be causing this intermittent problem with my lovely Zaffy? TIA,
The car needs to be driven whilst plugged into a diagnostic scanner reading all powertrain data when the fault occurs to see which system/sensor picks up the fault. If it is intermittent and not showing any fault codes on the ECU it is probably a wiring fault somewhere !