I needed to change the OPDA in my 2004 because there was too much lateral play in the pulse ring (the part you can see under the camshaft position sensor, or CPS). In my case, at high RPMs, it actually broke off the magnet in the CPS and I also found lots of metal filings inside of it. There was an allen-head screw holding the pulse ring on, but I was not able to tighten it. I assume that a bearing inside of the OPDA failed? I noticed that the new OPDA pulse ring was not held on with a screw, so hopefully the new part will work for a long time.
I took some photos and notes which I’ll post here. @Chris
, feel free to move this if you think it belongs elsewhere.
I ordered the Dorman 689-200, which also came with a CPS, gasket and an alignment tool (no instructions).
1. Loosen the sensor screws (5.5mm) and remove.
2. In the OEM OPDA, there is a small hole in the bottom of the sensor base and a corresponding hole in the pulse ring. To align them, you’ll need to rotate the crankshaft.
After realizing that I’d need to remove the fan, etc from above, I decided to do it from below instead with a 19mm wrench. Due to limited space, it did take quite a few partial turns to get things lined up.
If you don’t have a helper to watch the holes, get up and check them after a few turns. If you go past, you’ll have to go all the way around again.
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3. Once lined up, grab a toothpick or make a tool out of something. I made one out of wire with a bend to prevent it from falling out.
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4. Remove the hold-down bolt (13mm) and clamp. Lift out the OPDA. It will rotate counter-clockwise due to the spiral gear. Make a mental note of where things are when you are able to lift it straight up so you will know where to start when you install the new one.
You can see the old paper gasket that you’ll need to remove. I stuffed a clean rag in to the hole and used a razor blade and solvent to get it shiny (2nd photo).
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5. Use the alignment tool included with the new OPDA to lock the pulse ring from moving. The arrow will end up pointing to the rear of the vehicle, so insert the OPDA slightly counter-clockwise of that (where the old one was able to be lifted straight up after rotation). When it connects to the gear, it will rotate clockwise into position. Make sure to rotate it clockwise all the way until it stops.
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6. Clamp the OPDA back down to 17 ft. lbs. and then the reinstall the CPS (15 in. lbs.). The wiring harness for the CPS should be pointing straight back to the rear of the vehicle.