My check engine light came on this morning and I took it to Autozone and the OBDII said it was a P0340 Camshaft Position Sensor. My truck has 195,000 miles on it so it's probably due for a change. My questions are: 1) how dire is it that I get this done? Can it wait until the weekend or do I risk screwing up the engine? It is running just fine. 2) should I just get this part from Autozone or do I need to order a better model of the part online? 3) Is it just the CSP or is there some other parts associated with this I should go ahead and replace? 4) Do you happen to have any horror stories that can help me avoid issues? Thanks in advance!

 

There is a shaft assembly that also wears out. It mounts in the top rear of the engine where distributors were mounted in earlier models. The sensor mounts on top of it. When changing the shaft assembly, setting it back in exactly the same position is critical. With the miles on your truck, it might not be a bad idea. Sometimes when the shaft assembly goes bad, it will actually start to squeak. Replacement is simple, but not necessarily easy. Scruffybeast

 

The "Synchronizer" (gear drive and housing under the CMP sensor) wears out at high miles. Besides mounting the CMP sensor, it also drives the oil pump so a complete failure of the Synchronizer means a totaled engine. Obviously, this is not a repair that should be delayed.

The knockoff Synchronizer/CMP/alignment tool package available at many chain auto part stores may seem like a like a bargain compared to the individual OE parts. However, I've heard many horror stories about poor fit and short life before a repeat failure. In this case, I wouldn't use anything but OE Ford/Motorcraft parts in my engine.

The OE Synchronizer with a Ford part number is quite expensive but the Motorcraft piece is identical and usually costs somewhat less. After figuring out the Motorcraft number, the best deal I found was through Amazon.

There are many different models of CMP, Synchronizer and alignment tool, so be sure to get the exact parts for a 3.0L and for your year.

As mentioned above, the CMP needs to be correctly timed to the camshaft and this is best done with a special factory alignment tool. There are also DIY methods for replacing it without the special tool but I won't go into that here. Try a search for "CMP" or "Synchronizer" for more info.

 

I bookmarked these a while back.

https://www.ranger-forums.com/engine-drivetrain-122/how-3-0-cam-synchro-replacement-81674/
http://www.rangerpowersports.com/for...nc-226230.html

As previously stated, you want motorcraft parts. I bought mine from Geiser Ford on flea-bay for about $120 shipped for both. Great guy to deal with http://myworld.ebay.com/geiserford19...:X:CEM:US:1181 If they don't have it listed just send them a message. I always got a response within a day.

motorcraft syncronizer part number: F8DZ-12A362-AA
strator/sensor: DU81

Oh, and I used the "no tool" method and it took 20 minutes total. The hardest part was lining everything back up but it has been almost 10k miles and I have not had a problem since. A new Sharpie is your friend.

Hope this helps.

 

Well this is something. After being on solid for 3 days, the Check Engine light went off today! I'm not sure what to make of that. At this high of a mileage, I don't mind a little pre-emptive part change out to make sure I don't burn up the motor. Should I just try changing out the CMP sensor and see if that fixes it or should I just take it to the dealer and have them do it all? I hate to guess at it and I'm not going to get the special tool and worry with screwing up the alignment of the synchro. Your thoughts? (And thanks for the info, guys!)

 

It really is not that bad to do yourself. I suspect the dealer labor would be nuts. Read everything you can, go slow, and I am sure you will be fine. Heck if you were closer and had the parts, I'd swap them out for you. I took a sharpie and marked the position of the "finger" on whatever metal I could nearby. The key is that the gear at the bottom of the sync will need to slide "into" the gear that drives the oil pump. Wherever you set the "finger" it will move slightly left when inserted into the cylinder block (or head, whichever). I put it off for weeks and in the end it took 20 minutes and I succeeded.

 

These part numbers may or may not be the correct ones for his 3.0L - depends on the model year of his Ranger.

 

Did I not include the year? Drat. It's a 2000 6cyl. Maybe I'll just try the CMP for now. It's strange it was wrong enough to trip the Check Engine light and then went out. I hate flaky stuff like that! I've also read people have had issues with their alternator and it threw a P0340 code. My alternator is about a year old but that doesn't mean it couldn't be an issue there. (shrug) I really appreciate the help and the ideas.

 

sorry to bump an old thread, but my truck threw the P0340 code 2 weeks ago. Been running fine, so I put off buying a new sensor.

how risky is it to just replace the sensor and not the shaft assembly?

 

I wish I could add more to this thread for ya. My light went out and has been perfect ever since. I guess I got lucky. Never did anything with it and the truck continues to run like new. I hope someone else can chime in to help.

 

It's not that risky. I did mine at 100,000 miles, mostly as a precaution. In the 151,000 my truck has put on, a failed cam sensor has been my only cause of cel to date. I did the synchronizer at the same time a few years back. If you do decide to do the synchro, do yourself a favor and go oem, I went with dorman for about 2 weeks and it started leaking oil out from under the sensor. When you get the sensor make sure it's a 3 wire (I have a 2000 as well, pretty sure that's what mine was) and a 5.5 mm socket.

 

A 5.5mm socket is a good thing to have handy anyway, I've used mine to remove the instrument panel and clean the dust out of it several times in the past. I was surprised the standard socket kit doesn't come with one. Good info, btw.

 

Recently replaced the Cam Synchro in my 2003, on my first try I had a rough start and rough idling issues so assuming I was off a tooth I reseated it again and now it seems to be running normal. No rough starts in the last couple days and no odd idling issues. I replaced both the assembly and sensor.

My question is that I am going on a long road trip here in a few days and I am curious as to what are the symptoms I should look for on a bad install job? I am aware of the chirping and rough idling, but at constant high rpms for an extended amount of time, I am concerned about having to re-seat it. If Im not throwing codes, should I be ok?

Also, is it true that the system allows for a few degrees off in the synchro?