Yep.
If it's a high mileage engine that has never had a catch can, the cumulative oil vapour in the intake system can be significant.
I've seen a V9X intercooler emptied into a bucket - looked like approx. half a litre of oil.
And it's likely there will be significant carbon in the intake manifold, and possibly valve train & cylinder head, if it's severe.
But if the oil & filter has been changed regularly over the life of the engine, and it hasn't been abused, the oil & carbon build-up could be quite mild because the blow-by is lower/less.
All depends on the piston & bore wear.
