Join Date: Sep 2005
Location: Geismar, LA, USA
Re: New project:1989 Ford Mustang GT convertible
Listen for scraping, yes. However, good idea:
Get a case of Marvel Mystery Oil. Yes- a case.
Fill up each cylinder through the spark plug socket until it's pouring out (must be through the plug socket, not the exhaust port- a closed valve would not allow it into the cylinders. Hand thread the plugs into place.
Let it sit for 3-4 days.
Mark the crank and somewhere on the engine that doesn't move, as a reference point.
Turn the crank 10% or so (not too much, in case there is rust).
Refill at the spark plug socket, hand thread plugs.
Wait 3-4 days.
Do this until the two marks line up again, indicating a full cycle of the crankshaft. If you want, do it twice.
It takes a good while, but if you do it properly, you'll salvage the engine (in the chance of rus). The Marvel is an amazing product and will break down the rust without any issue, but do leave it for a few days to ensure that it's done its job. Again, fill the cylinder until it pours out. That's the only way to get the most effect.