Originally Posted by Jake walking to
How do I fix that? Will an engine flush work or do I need to clean the ports another way?
The best thing to do would be to pull the heads and have them hot tanked and rebuilt, but tightening up the top end may lead to issues with the bottom end if it has been mistreated like that.
Pull the valve covers and manually remove as much gunk as you possibly can.
Reinstall the valve covers and flush out the engine by adding a quart of engine flush, diesel or kerosene.
Start the engine and let it warm up good and circulate the mixture around, do not rev it hard.
Then shut the engine off and drain out the contaminated oil and remove the oil filter, be careful it will be HOT.
Replace drain plug and use a new oil filter, fill with new oil.
I would change out the oil early the next 2-3 times.
Keep an eye on it and as soon as it goes to black, change it out.