When I start my 2006 ford escape it makes a noise that sounds like a horn... It also makes it from time to time when I am accelerating. Pep Boys told me I need to change the pcv lines and all kind of stuff that will eventually end up costing me about $800. I am wondering if just changing my pcv- valve will be enough.

SOURCE: pcv valve

The positive Crank Case Ventilation (PCV) is coming from the intake manifold and usually goes to the Valve cover On that year it could be in the back of on the side of the Rocker covers ( Valve Cover) find the Vacuum line coming out of your intake and follow it, It should lead you to the Pcv

SOURCE: Ford Freestyle factory radio and pcv valve installation

this manual may be usefull to you

http://cgi.ebay.com/ebaymotors/2006-Ford-Freestyle-500-Montego-Service-Repair-Manuals_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247QQcategoryZ6759QQihZ009QQitemZ190013794897QQrdZ1QQsspagenameZWD1V

SOURCE: 2002 ford Ranger 3.0 v6 (auto) rear end noise when accelerating on curves.

Grab the bed of the truck and vigorously rock the vehicle from side to side. If you hear clunking in the axle, you probably need to check the carrier bearings in the differential. I had the carrier bearings, wheel bearings, and seals replaced in my mother-in-law's 1991 Ranger for $280, and it rides like a new truck. Well, ok, it rides like an 18 year old truck with a new rear end. I provided the wheel bearings and seals to the shop, and they provided the carrier bearing, lube, and labor. While the axles are out, check the surface where the axles ride on the bearings. If they are worn, there are undersized bearing available, but it is usually cheaper and easier to just by new axles.

SOURCE: Change Oil light came on my 2006 Ford Escape

The change oil light is controlled by the main engine computer which monitors driving conditions and clock hours. Based on this data it suggest an oil change interval. The system, however has no way to know the oil was changed unless you tell it so. In your owners manual there is a procedure to "reset" this process in the engines computer. its normally done by holding a button and turning the ignition key on at the same time. It should be listed under oil change in the owners manual.

SOURCE: Loud rattling noise while accelerating

First thing i would try...... ISOHEET, Red bottle..... allows water to be mixed into the fuel and be burnt out of the tank.
get a good qaulity fuel injection cleaner, if you can locate the brand MALCO, i found it quite succesful..... and go with a full tank of premium fuel such as ammoco or shell......do not use yellow bottle of heet

Testimonial: "Might be water in the tank?"