Vauxhall Vectra 1.9cdti - Vectra C Engine Revs on Its Own - Walkergw6


I have a 2008 Vectra 1.9 cdti. The engine produced a P0400 code (EGR Valve) last week. I replaced the EGR valve today with a new one and cleaned the Idle Control Valve (Throttle Body). However the engine still revs (the RPM needle bounces up and down between 1000 RPM and 3000 RPM) a few times on its own when I depress the clutch. This happens randomly and there is no discernable pattern.

Also the car tends to surge forward when I am driving for no apparent reason. Sometime the engine seems to temporarily lose power when I am driving.

In summary I have:
Replaced the EGR Valve
Cleaned the Idle Control Valve (Throttle Body)
Confirmed the swirl flap rod is still in place

No Fault Codes Present

Cleaned the MAP Sensor

Installed New Air Filter

Can anyone help me with the problem?
Thanks in advance.

Vauxhall Vectra 1.9cdti - Vectra C Engine Revs on Its Own - Railroad.

You didn't clean the throttle body or idle speed control valve because diesel engines don't have either. What you cleaned would have been the anti-shudder valve, which is a butterfly valve but not a throttle. I would remove the entire air intake including the manifold and thoroughly clean it, removing all the thick sludge that forms on the inside. Make sure the turbo wastegate actuator moves freely and easily and that it works.


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