Hand crank resistance when warm

Hi,

I have a 928 S4 1989 US Spec, recently imported into the UK. The car was in a museum for 4 years before my purchase.

To prepare the car for the road, a 928 specialist has been working on fluid, seals, etc replacement. One of the things he noticed that when hand cranking the car cold, it felt normal, however when he hand cranked after the car got up to temperature, he felt more resistance than he would expect to see. The thrust bearing has been checked and this is fine. Has anyone had this issue or is it common with the US spec car. 

He suggest taking the engine out and checking for possible crank or a associated thrust bearing problem.

It has not been driven other than onto a transporter, so we are trying a belt and braces approach.

Any advice would be appreciated.
 

A couple of questions:

How much more resistance?  Hard to measure for sure.

When it started and warmed up were there any issues or warning lights?  Did it warm to full temperature and then cycle the cooling system?  Was the idle control okay (steady)

Did it restart a second time when warm?

Hand cranking has a fair bit of resistance cold or hot, more so if recently run and warm, to overcome the compression.  If he pulls the sparkplugs does it still have a lot of resistance?

Does it have an automatic transmission?

For resistance, the mechanic tried to explain this as, for cold it would be about 40 ft.lbs, when hot, this was 60 ft.lbs. He looks after quite a few 928's, however he has not experienced this on a UK or ROW car. He did drop the sump, from what he could see, everything looked as new condition, except for one bearing which had a slight mark. This he replaced.

At start up, no issues with warning lights, settled to steady idle, did not cut out. No problems restarting car.

Have not tried pulling the spark plugs to see if there is any difference. Will ask.

Automatic transmission.