It's been a while - and no response to my last few updates but I have noticed something when driving (or rather idling) on the vacuum / economy gauge.

When starting from cold it behaves as expected, not quite fully to the left since the cold-start devices are functioning. However once the temperature reaches the magic number the engine revs lower but the economy gauge isn't quite all the way to the left, it's about 5-7% off. It's not until the engine is run for quite some time that it eventually sits to the far left at idle.

To me this would be an indication that the engine reaches temperature but the components further away take longer for the heat to raise, such things a seal or what-ever.

Am I on the right line of thinking with this? Could anyone offer a suggestion to determine what it is?

Many thanks,

Glyn B. - still lovin' the W124 experience, but hating the rising fuels costs