Camshaft and Crankshaft Sensors--I'M BACK

OK, here's an update. A few weeks ago I did a more thorough cleaning of the throttle body area. I also tossed a can of Sea Foam in the gas tank. Wife reported no drivability problems--there was no one time jerk with the Check Engine Light flashing on--until yesterday when she said it jerked once at highway speed (she didn't notice if light came on or not).

Today I went to a Chrysler dealer and got a copy of service bulletin

If the wife reports the engine jerking problem again, I will disconnect the knock sensor and have her drive it to see if the problem goes away. However, seems to me I will have another problem, namely the potential for pinging and a constantly lit up Check Engine Light. Won't the loss of the knock sensor cause drivability problems, pinging, loss of gas mileage, etc., esp. in Minnesota with its wide temperature swings? Why don't they recommend replacing the knock sensor?

Just disconnect the damn thing and quit worrying about it.

Amen, and if you hear pinging buy a higher grade of fuel. Older knock sensors are notorious for starting to be "fooled" by normal engine noises as the engine gets some wear on it (wirst pin rattle, piston slap, etc.) and will cause the engine power to surge as the sensor fiddles around with the ignition timing trying to eliminate a knock that isn't really a knock at all.

Disconnecting it will do exactly the opposite of everything you mentioned, exceot for pinging. Gas mileage will be better, driveability will be better. The downside is that depending on the enigne, you may have to buy a higher grade of fuel especially in hot weather.

Sorry, I'm too analytical for that

Thank you. This is the type of information I'm looking for to try to solve this mysterious problem. When the problem occurs it occurs at about the same time/distance in my wife's drive to work. So it would seem to be temperature related. What could the knock sensor be hearing at the point the engine finally gets fully warmed up that tricks it into sending a signal to the PCM?

Again, thanks for the info. Based on your response I can only conclude that the knock sensor is on vehicles so they can run the engines on the lowest quality fuel. Otherwise, they are what is known as a "whee" part, you know, you take it off the vehicle, throw it over your shoulder and exclaim "WHEE!!" making everything better.

Obviously the knock sensor function is flawed and there is no fix. Just use the correct fuel and you should be OK.

It appears to be as you say. Now I'm wondering how long Chrysler has been putting useless parts on their engines? In other words, did they continue using this same knock sensor set-up for subsequent years?

Analytical and anal are not the same thing.

Interesting that anal is the root word for analytical though, is it not?

No, newer ones are much better. Its not so much the sensor as the signal processing that follows it to separate unrelated engine noises from real detonation sounds. Newer signal processing, for example, eliminates sounds that occur at crankshaft positions that couldn't possibly be due to detonation. There's a lot more to it than that, but I don't know what all else they do.