Here is a photo of my original crankshaft position sensor after removal sitting in the box from the new CPS:


Notice the crud on the metal at the end. (Sorry, forgot to take photo of new sensor with its spotless end; didn't want to remove it from engine.)

If I were to clean that surface, would this CPS operate correctly? Or are CPS failures due to internal breakage?

Thanks

 

The heat from the engine eventually affects it. I change mine out every 4 years as preventive maintenance.

 

I am so tired of this - the idea has been proposed several times since I joined here over thirteen years ago. The thing is, NO ONE to my knowledge does anything but propose the idea - no one wipes it off and tests to see if the car will run right.
Wipe it off and put it back in and tell us what you get. The rest of us didn[t do that, we simply threw the part away.

In MY case, the sensor looked fine, there was nothing to wipe off, so I changed it and that took care of that. If we keep asking the same question but not trying the experiment, we will never know. But I STRONGLY suspect it is heat related, as it is always reported (almost always) that the car starts after sitting 1/2 hour and runs for a while or a few days, then fails again.

 

Would you also recommend doing that PM to the Camshaft Sensor located on top of the motor? My 2007 Coupe actually still has both of these original OEM sensors still in service. I'm convinced the primary failure mode is heat-related, but I also believe this failure mode is influenced by the time dependent exposure the sensor sees the heat. In my case, where I only drive the car sparingly and not as a daily driver, the exposure time these sensors see the heat from the engine is reduced. Anyway, just talking out loud so to speak. I still carry spares in the trunk just in case.

 

My camshaft sensor actually failed during the factory warranty, the car would have trouble cranking/starting but wouldn't leave you stranded (they had to order it). I have changed it once since since it is in front of the engine I don't think the heat really gets to it.

Even the Bosch CPS description on Rockauto mentions temperature more than once, https://www.rockauto.com/en/moreinfo...k=500351&jsn=3

 

THAT is an interesting find. I mean, when the manufacturer mentions temperature like that, makes you think temp might JUST be an Achilles heal.

 

I probably just jinxed myself, but I am running original CPS' in both my Crossfires, one at 64k and the other at 42k miles. I assume they are the same for n/a and SRT6, so I should probably order one to have on hand.

 

Somehow among the multitude of threads about crankshaft position sensors on the forum, I missed the discussions about heat being the likely cause of failure. Nor did it occur to me to retry the cleaned-up old one until after I had installed the new one. Thanks for the info.

Aside: My car sat unused in the cold, damp, slightly below and slightly above freezing temperatures for two weeks before exhibiting bad behavior and throwing the P0335 code. The bad behavior vanished a few hours later when the car restarted and ran fine a few times, but by that point I was afraid of catastrophic part failure and was committed to replacing it.

Possible tech tip: While talking to an ex-Chrysler/Stellantis guy the day after doing the replacement, he said that it was easier to access the crankshaft position sensor from the under the car. Perhaps someone with a lift can confirm.

 

I have a lift but can’t imagine trying to reach the CPS from below. Has he ever worked on a xf?

 

He was probably a salesman at a dealership, or a service manager. LOL

 

A simple way to test a defective CPS that has temperature related faillure is to connect an ( Ω ) omhmeter to the CPS .When cold the Ω meter will show continuity, then, use an hair dryer and heat the boby of the CPS and at one point you will see the circuit to open . . . let it cool and the circuit will come back to life.

I was able many time to reproduce the open circuit condition when the original CPS of my XF went defective . This test will confirm the cause of the no start condition or a stall in the trafic when engine get hot egnough.

Daniel

 

That is the most asinine stupid statement I've heard in 62 years. Pop the hood and tell me how the HELL you are going to reach the CPS from below.

That HAD to be a salesperson....
No, wait, this was at a dealership - probably their master mechanic.

From my sigline: WARNING - Any mention of taking your car to a Chrysler dealer will result in a near-profannity-laced post on my part. PLEASE do not take it personally!

 

Good diagnostic. Thanks

Yep, he had been on the sales side. I didn't think you could get around that shield from underneath, but it was worth asking.

 

It's not the shield, it is located on top the engine above the transmission. There is no way to reach it much less remove and replace. I wouldn't listen to him much less let him touch it.