Not saying that wasn’t the source of the overheat, but it is a very rare occurrence. And kudos’s to you for tackling a timing chain job over a motor swap.
I'm sure you haven’t owned the car for its whole life so it's safe to assume maintenance wasn’t performed when needed. So if someone neglected oil changes to every fifteen thousand miles, it possible to have excessive ware on the chains. The average person doesn’t care about their car after 100,000 miles, it's amazing what frequent oil changes can do.
*Sometimes* a blitz fix is easier than spending allot of time on finding an exact cause. Just like what I did on my Town car,wouldn’t idle right so I changed the engine, thinking the intake had a vacuum leak.
Thank you for the compliment.
I did not purchase the Mark new, but I have owned it since 23,000 miles and when I bought the car, it was still under warranty.
As soon as I bought the car, I changed the oil and put in Mobile 1 5W30 Synthetic. I changed the oil every 5000 miles and never used anything except Mobil 1 sythetic 5W30.
When Mobil came out with the "Extended Performance" synthetic, I started using it and changes were extended to 10,000 miles. I also switched from the Motorcraft oil filter to the mobil filter and then switched again when fram came out with the 15,000 mile filter.
The oil changes and trans fluid changes were done like clock work. The cooling system fluid changes were not done as religiously, but the system was not clogged or rotting out.
When looking inside the engine with the front cover and valve covers off, it was remarkably clean and free from any signs of dirt and/or sludge build up.
Even though the engine was overheating, it did not sound bad, but after replacing the chains, plugs, and coils, the improvement in performance was very noticeable.
The car was not abused, but the chains were certainly out of spec. It really does have over 235,000 miles.
I am representing my friend that helped my with the job in Court tomorrow. If I can keep him out of jail, I will ask him for a link to the article and I will try to post here for everyone to judge for themselves.