My 80 Citation V6 did this 3 times. It didn't do it 4 years ago:
The starter spins fast cold, starts right up usually; sometimes needs couple tries and starting fluid. (Gas is old).
Then after 10 minutes warm up, I try it again. Now the starter barely turns: RRR---rrr---rrrrr... It sounds like it's killing the battery, like something dragging.
Facts: Old battery OK. But I bought a new one in late January, still does this.
Battery proper size for car,. Was tempted to get marine battery but car needed mods to get it to fit.
Alternator rebuilt 4 years ago, it had no problems but I checked it anyway. It puts out 14.3 VDC at fast idle,
brites on.
Starter was working but I rebuilt it anyway 4 years ago.
Battery cables good but I redid them recently. They are proper length, gauge.
Terminals good, Marine bronze w/stainless hardware.
Car sat 4 years, so only a few miles on it since the rebuilt starter/alternator.
It runs good on the road and highway. Seems to have good compression.
Replaced bearings 4 years ago when I replaced a seal. All mains showed scuffing like overheating once , said the
parts store. All bearings in spec by PlastiGauge, changed 'em anyway.
Cylinders still showed honing makes. pistons seemed free.
Car has never been overheated while I owned it. Flushed rad/block, new hoses/belts, new used heater core
(leaked); new thermostat (it was old but free.). Radiator cap good. Fan and switch/relay all working. Water
pump ok. No coolant leaks as of 4 years ago, or now.
Regular oil changes, oil pressure fine by aftermarket gauges. Proper weight of oil, too.
I changed oil when I bought it. Changed it when I returned 4 years later, too.
It did this in 48 degree weather, even 75 degrees (I am in S. AZ, freezes rare.)
I can put the boost on my charger on it while I try it, or charge battery overnight, I still get this hot dragging
There is possibility starter getting overheated by manifold, but this never happened before. I did not check last time if it was
hot. Again, this problem is very new.