I think a compression check makes sense. I will try to come up with a compression checker. I had one years ago, but have not worked on vehicles for some time. It would be good to understand just what is happening on these back two plugs.

At the same time it is hard to see how it would go from starting with no trouble to not starting at all based on this condition overnight following another out of the ordinary situation like the hose break. It is also complicated by the back plug being the only one firing with this last set of plugs. Not exactly what one might suspect if there was a gasket leak near this plug. However, something is definitly different on these back two plugs. It is what made me wonder about the idea of transmission fluid being drawn up into the engine - I noticed this idea on some of the old posts. I do not know where the vacuum connection is to the intake manifold, but it might be that it is at a location that would effect some of the plugs more than others...??

The hose break more correctly is a breaking of the plastic gooseneck that comes out of the radiator. The expanded portion of the plastic at the end of the gooseneck that is used to lock the hose over the gooseneck extension, snapped, leaving the hose clamp with no grip on the remaining portion that was left attached to the radiator. I think that this is a natural weakening of plastic that brought this about - finally gave way, I think.

I must admit, I wondered about the plugs. The ones that were last installed were H9DCO's. The only replacements that I could find were HR9DC. All the stores said that this is the present Bosh recommended plug. At the same time, the plugs that were in the car at the time were not that old, so the shop that worked on it, that specializes in MB had to have thought the non-"R" plug was the right one. I will shop around tomorrow and see if I can find some of the H9DCO's

Thanks again,

Marsden