[vundba]

I've got a 89 928 s4 181,000 miles clean car .purchased on e-bay about 1 1/2 months ago engine seemed to always turn over hard but when running it was fine up until a week ago.When cold it would run fine and idle smooth but as engine temps came up to normal, idle would be erratic and engine would just seize up.If I tried to restart engine it would not turn over,but would be fine once car cooled off.I noticed upper radiator hose was very hot and lower hose was cool,so I replaced thermostat and coolant temp sensor,but same thing.currently I've removed valve covers to check top end and am now going to remove oil pan and bellhousing cover to check for thrust bearing failure but I would think if this was the case it would have issues even when cold.
any ideas would be great,
thanks!