Yesterday, I replaced the leaky oil pressure sender switch on my 99' Ford Escort ZX2. This is just my one-time experience and what worked for me. I didn't remove the starter or anything. Hopefully this will save others some time and headaches.
One random day, I checked my oil and it was only as high as the very bottom of the dipstick where it says "ADD." It was low, but the oil light on the dash never came on. If I added oil, it would just leak out all the new oil to the point explained previously on the dipstick. It would also leak a bit more if the car was not on a flat angle. The drip appeared to be coming from the drain plug of the oil pan.
How I found the leak:
Brake cleaner, Oil UV dye, and blacklight. If you expect to use this method outside on a sunny day, be prepared to wrap the front and the sides of the car to block the sunlight. Otherwise, you will not see the dye clear enough.
- 1/2" ratchet ( or 3/8" ratchet and a 1/2" adapter etc. ). There is a metal tube in front of the sensor. I couldn't manage to get any pliers near it. Would recommend a flexible ratchet. But a fixed one also works.
- 2" extension.
- 15/16" 6 point deep socket. A common socket set will not have this large of a socket. I would recommend a non-impact type of socket because they are heavy and become unwieldy in this situation.
- Teflon/plumbers tape ( if you opt to use it. )
- Needle nose pliers.
- Jack stands*, gloves, eye protection, etc.
You can reach the sensor somewhat from the top of the engine, but mostly from below. From the top, if you look directly down, between the cables of the acceleration linkages, with a light you should see the sensor on the back of the engine. You can reach around the alternator with your left arm. However, the space there is very limited. If you have flexible tools, smaller arms, that might work for you. I removed the electrical connection of the sensor from the top that way. The overall struggle I had with replacing this sensor was mostly the limited view. Being able to see what you're trying to work on at the same time. Where your arm needs to go, your head also needs to be there too to see anything. But you can get more of a view and manage a ratchet etc. from the bottom.
- Remove the electrical connector from the old sensor. The sensor has threads on top, and you'd think it would screw on but it just pulls off and presses back on. I used a pair of needle nose pliers from the top of the engine. With a good grip and slight wiggle, it should come off fairly easily. Push the connector out of the way for the socket.
- From the bottom, remove the old sensor using the ratchet, extension, and socket. I found it easier to put the extension and socket on the old sensor. Then the ratchet onto the extension. There is an annoying metal hose in front of the sensor. I had to work the socket kind of above that hose where there is more room and come down to the sensor. No oil leaked out, but be prepared for a bit to.
- Install the new sensor.
- The new sensor I received had something of sealer on the threads. I put teflon tape on it anyways.
- I was unable to install the new sensor from the bottom. Given that metal hose in front, I could not fit the deep socket - now with the sensor in it - in that small space. With the lack of view, I could not get the thread started and my arms began to burn out. I took a different approach.
- I took my smallest 1/4" socket and put the sensors threads in it. Then held the two together temporarily using electrical tape. The idea was to use that on a thinner and lighter screwdriver just to get the sensor started. From the top, I was able to go around the alternator and get the sensor threaded easily. Then I pulled off the 1/4" socket along with the tape. You can get creative or just use any stick really.
- From the bottom, finish screwing in the sensor with ratchet. I took the spark plug approach; snug, then another quarter turn.
- Push back on the electrical connector and test for leaks.