Hi
I have an X-Type 2d. It runs perfectly but a little coarse - starts instantly, no smoke and gives huge MPG and no error codes. But the engine has a violent vibration at idle that can be felt through the driver's seat. The idle speed 800rpm and constant plus or minus a few RPM.

It's not the DMF which is fairly new or the engine mounts. New injectors, filters, EGR, MAF, camshaft and crankshaft sensors all failed to cure.

Using my cheap D900 mini-scanner from ebay, I've been reading the MAF sensor 'live data', i.e. the quantity of air entering the turbo via the air filter (It's measured in 'gs' - grams of air per second). It bobs about at idle from 4gs to 8gs. This seems very high from what I read elsewhere in relation to other cars. Apparently, it should also be fairly constant at any given engine speed. The ECU controls the amount of fuel injected to produce the right air/fuel ratio so it must be struggling to do so smoothly if the MAF air intake readings are erratic - at least that's what I would have thought.

I'm wondering if this might be a clue to my engine shake - incorrect data going from the MAF to the ECU.

Does anyone know what the MAF readings should be on the 2d engine at idle? I can't find anything on it anywhere even in Jaguar's Workshop manual. Or what would cause erratic MAF readings from a good MAF?

It's a tough one.

Thanks