I get good prices locally on Ford parts, and the tech talked me into buying VC-1. He looked at the truck and said its orange coolant and while you can just add yellow it is not a good idea because you don't know what the last owner may have used.
He said if it was his truck - let a quart go, or drain and refill with tap, add the VC-1. Drive for 10-20 miles. He said the VC-1 cleans the heater core and radiator for better heat transfer.
Drain again refill with tap, let come up to temp. Note how much comes out, so you know how much full strength to add back to the block.
If it is really dirty, put a hose in and do some flushing, but optional if clean. Repeat with distilled, drain again. Balance the water with full strength yellow, Then add back 50/50 yellow/distilled and you are all set. Must remove the heater inlet in the 6.2L to bleed the air (similar to a 4.6L).
Also got a new Ford Tstat, it was like $12. Same Tstat that a 91 Towncar would use, never really heard of those failing, but he said it happens with such high miles. They suggest it to customers when they service coolant over 120K.
He said if it was his truck - let a quart go, or drain and refill with tap, add the VC-1. Drive for 10-20 miles. He said the VC-1 cleans the heater core and radiator for better heat transfer.
Drain again refill with tap, let come up to temp. Note how much comes out, so you know how much full strength to add back to the block.
If it is really dirty, put a hose in and do some flushing, but optional if clean. Repeat with distilled, drain again. Balance the water with full strength yellow, Then add back 50/50 yellow/distilled and you are all set. Must remove the heater inlet in the 6.2L to bleed the air (similar to a 4.6L).
Also got a new Ford Tstat, it was like $12. Same Tstat that a 91 Towncar would use, never really heard of those failing, but he said it happens with such high miles. They suggest it to customers when they service coolant over 120K.