DB9 Top Gear Track
AO Silver Member
Join Date: Jan 2007
Location: United Kingdom
County: East Sussex
When you rev the engine does the upper turbo hose swell? It will be 'squishy' at rest.
Can't think why oily gunk under the upper hose near the battery would be a symptom of a failing tubo, sounds more like a leak in the upper hose. Oil (to some extent on all turbo engines) does find its way into the upper hose via the turbo oil seals, it then mixes with the sooty exhaust fumes from the EGR and clogs up your inlet manifold, swirl valves and map sensor...which is why it should be cleaned from time -to-time.
If you haven't had the EGR off and cleaned it for some time (as described in the sticky at the top of the forum) it's almost certainly contributing (if not causing) your problems.
Loose - not close, compact, or tight in structure or arrangement
Lose - to part with or come to be without, as through theft, accident, negligence, etc.