Hi,
having found useful stuff on here to help me fix my non running heater fan I have been searching for info regarding another problem. No luck so far so thought I'd ask the direct question and see what others know.
It started a year ago when the Doblo failed its MOT on emissions. I was advised to add a fuel system cleaner and run it at high revs ( I normally run low revs and high gears - using the ample torque. I did this and it dropped the emissions from 7% to 0.7% for a pass.
However, after that there was a rattly noise in the engine a bit like a wide (manually adjusted) tappet. Since these are hydraulic tappets it can't be that and anyway why would one suddenly change? The noise has remain fairly consistent since then being engine speed related and generally unaffected by engine temperature.
In the year since it has had no end of things tried including:
further system cleaners
oil changes
bottom pulley change
timing belt change (due anyway @50k miles)
oil additive
injectors rebuilt (£600!)
and all to no avail as the noise is still much the same.
In this period the indicated fuel consumption has remained good, slightly increasing if anything to an long term average of 60mpg. Only recently has there been an indication of a minor reduction in power.
From threads on here I am wondering whether it is worth inspecting the EGR valve for clogging. I have already confirmed that fuse F11 is OK (other fuel injection functions?).
Does anyone have any suggestions of cause or remedy? I am beginning to think that I might have to remove the camshaft to check the tappets and then the head to check on the valves themselves.
All help welcomed.
thanks
dgary
having found useful stuff on here to help me fix my non running heater fan I have been searching for info regarding another problem. No luck so far so thought I'd ask the direct question and see what others know.
It started a year ago when the Doblo failed its MOT on emissions. I was advised to add a fuel system cleaner and run it at high revs ( I normally run low revs and high gears - using the ample torque. I did this and it dropped the emissions from 7% to 0.7% for a pass.
However, after that there was a rattly noise in the engine a bit like a wide (manually adjusted) tappet. Since these are hydraulic tappets it can't be that and anyway why would one suddenly change? The noise has remain fairly consistent since then being engine speed related and generally unaffected by engine temperature.
In the year since it has had no end of things tried including:
further system cleaners
oil changes
bottom pulley change
timing belt change (due anyway @50k miles)
oil additive
injectors rebuilt (£600!)
and all to no avail as the noise is still much the same.
In this period the indicated fuel consumption has remained good, slightly increasing if anything to an long term average of 60mpg. Only recently has there been an indication of a minor reduction in power.
From threads on here I am wondering whether it is worth inspecting the EGR valve for clogging. I have already confirmed that fuse F11 is OK (other fuel injection functions?).
Does anyone have any suggestions of cause or remedy? I am beginning to think that I might have to remove the camshaft to check the tappets and then the head to check on the valves themselves.
All help welcomed.
thanks
dgary