Tuesday, 4 September 2012

Vivaro couldn't pull the skin off a rice pudding.


The van has developed a running fault that started a month or so ago and has become progressively worse. It has taken us some time to chase down the cause of this problem.


The symptoms:

 This fault shows it's self when you drive away from a stand still. You have to push down the accelerator pedal alot further than is normal to get it to speed up enough to change up to second gear. On lifting your foot off the accelerator pedal to change gear the vehicle speeds up while you are changing up. On pressing down on the pedal again the van struggles to gain speed. It feels like it is holding back.

 
Thought process and action.
 
This suggests that it is a fuel problem. But it has nothing to do with fuel, injectors, high pressure pump, fuel filter or related sensors. Another suggestion was the turbo but we could hear it spooling up. We checked the  turbo pipes, ducting were tight and not blocked. We found a couple of lose hose clips but not enough to cause power loss. Also checked to make sure the waste gate solenoid worked as it should.

At one point we thought the ECU needed a re-boot, again it did not seem likely. Thinking about it, it was a flow problem the only other thing that came to mind was the air flow meter. Before we paid out on a new meter we surfed some motoring forums for pointers but no one had this fault it would seem. We came across a thread that suggested the changing of the airflow meter would sort it out but this gentleman also had the crank sensor replace. After a short discussion we decided to go with the air flow meter. Bingo! got it in one and what a relief, it would have been an expensive mistake otherwise.


Air flow meter
 

Extra work.

 
While we had the air filter housing off,  which is a pig remove, we thought it prudent to check the glow plugs as it only takes a couple of minutes with a volt meter. We found that two of the plugs didn't work. The ERG valve drew my attention because the inlet manifold was covered in oil  suggesting the gasket had failed or the bolts were lose. You have to be patient when removing it as it has a build up of oil residue. On removal, it was found clogged with a thick coagulated oil  that took a bit of cleaning up.
 

It runs and pulls like a train now. The rice pudding skin doesn't stand a chance!


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