According to the 1998 Ford Escort Owner Guide :
A Ford dealer will change the PCV valve at no cost ( except California and
Canada ) at ( 60,000 miles/ 96,000 kilometers )
the pcv valve is on the back right of the valve cover if not get one
pull off from front where the pcv is located to the back of the intake manifold you might have to remove the the thermostat housing to get to it and put a new pcv valve the hose is a dealer part or check rockauto.com it's like 35 bucks
I have a 1998 Ford Escort ZX2 and the PCV valve was located to the right of the exhaust heat shield in front of the engine block. All I had to do was pull the rubber elbow out that was connected to the PCV valve and then pull the valve out. It was arguably the easiest maintenance work I've done on a car. I didn't have to take apart the heat shield or any other component.
It connects to the crankcase vent, the air filter and the valve cover.
I have a 1999 ZX2 and had a hard time finding the PCV valve as well, but here's your answer: Remove the heat shield from the exhaust manifold. (This is the front of the engine, clse to the radiator.) You should see an adjacent hose going into the engine. Lightly pull on the hose and it will come off, revealing your PCV valve. I have a 2000 ZX2 and find the PVC valve on the right side of the heat shield on front of engine. It was not necessary to remove the heat shield in order to access the PVC valve. Simply remove the hose gently or you will break the adjacent hose. If you should damage the hose the part number is PA6 and will need to acquire through a Ford dealership.
on the valve cover it will have a small vacum line coming out of it. it looks like a little elbow
Check the PCV Valve in the front half way down the engine
just right of the exhaust manifold. little black rubber pipe/elbow connects to it.
www.teamzx2.com
Is the loud noise an intermittent squeak? My 1998 ZX2 had a very annoying loud squeak that turned out to be due to the use of the wrong PCV valve. The ZX2 2.0L engine apparently comes in SOHC and DOHC versions and if you use the PCV valve intended for the SOHC engine in the DOHC engine, you will get the squeak. Before I knew this, more than one garage has installed the wrong one on my ZX2.
I Have a ZX2 myself, and I have had the same problem. After replacing the variable camshaft timing sensor grommet, I also replaced the valve cover gasket. You should be able to only change the valve cover gasket and be fine. Matthew D
On the bottom inside next to the engine on the air intake there is a elbow there that can become bad and make a air leak