I need a guy's opinion on my car?

I have a 2006 Scion TC with about 115,000 miles. Brand new tires. Brand new windshield and fairly clean interior. It also has air conditioning, heating, cruise control, power windows, CD player, AM/FM radio, rear spoiler, etc. I'm still paying it off but only owe $1,800 left on my loan. However, the engine has a knock in it. I've gotten about 3 different estimates and all of them were between $2,500 - $4,000 to fix. My question is would it be worth it to fix? I plan on selling it either on Craigslist or to a dealership so I can get a small 4cylinder pick up truck. My options are:
Sell it as is on Craigslist but for? Whatever it's worth.
Take it to a dealership and have them pay off my loan and get a small pick up from them.
Or fix the problem and sell it on Craigslist and use that money to put down on a pick up.
What should I do?

Added (1). @There are some who call me Tim: We bought the car used in 2013. It was mainly a commuter car for me to get to school and back. We're looking for a small pick up for my boyfriend to use to get to work that way we can park our Dodge Ram 2500 and not rack up too many miles on it since it is fairly new. We would have about $1,000 as a down payment and we have been offered $2,000 from a local Ford dealership even with the engine needing to be replaced.

Added (2). So basically getting our TC off our hands since it is sitting and we're paying $350 a month. Then we can get a small pickup and pay maybe $150 a month.

I guess #4 cyclinder misfiring?

For check i removed all plug wires one by one. When it came to no.4 idle didn't change.

After this, i replaced rotor arm, plugs, wires, cap but still does same thing.

i can see spark from cable to cap but with no idle changes @4

what can be the problem?

2.0 Ford pinto engine with weber 32/36

Problem with Steering Wheel in Ford Aspire?

This is a problem that just started happening last week, So pretty much when I go to turn the wheel, If I turn it to fast the wheel makes a weird snap sound then is unresponsive with the tires (it still turns the wheel but the tires don't respond) the only way to fix it so far, has been restarting the car, then it works like normal.

I'm 16 btw, so I know nothing about cars and none of my family knows about cars, what do I do?

1999 Ford Windstar 3.8L Power Steering Pump Replacement?

I have replaced the Power Steering pump. My problem is that the high pressure hose leading into the new pump is leaking fluid. The threads leading into the pump do not leak and I placed the "teflon" washer on the male end of the high pressure hose threads as explained in the instruction manual with the new power steering pump. The high pressure hose fitting where the line and the actual threaded nut "free float" is the cause of the leak.

I have read several ford forums, but have not found a way to seal this off. Can anyone help out?

Can an auto dealership hold money owed on a car they bought from you?

I sold my car 3.5 months ago to a Ford dealership in Washington. They told me they d have the check to me in three days. About three weeks later, I called after not getting anything. They said I had filled out a form wrong and the bank did not have the title. I filled out more paperwork, including the title documents and waited again.

A month later, they had me sign another form related to the title. I was confused and they say California wanted it. I researched the title process and sent them every required document. I finally got angry at sales rep and he gave me the finance manager, who likes to avoid my calls.

When I finally talked to the finance manager, he said that he'd sold my car and that he still didn't have the title. Apparently the bank that financed the sale of my car to the new owner was holding his money on my car and 10 other vehicles until they got my title.

I researched Washington law and it seems you can't even sell a car in this state without having a title. I've reached out to Ford and they have no regulatory departments on dealerships. What should I do. It's $1100. Not a large amount of money, but I'd like it back.