cam sensor magnet goes south in 8 months

[Guest imported_blazer1997]

Replaced the cam sensor, new sprockets, chain waterpump with all GM parts

Last week started getting the service light. Checked today, and no magnets at all.

The magnet was replaced the hard way from the back of the sprocket per the service manual.

Was the part just defective or something else going on???

Thanks Larry

[Roadster90]

Think it is a design flaw....at any rate, roughly two years ago I replaced everything as you did, but even though I had it all out I glued mine anyway and it is fine so far...

[Guest imported_blazer1997]

Thanks nic but this getting old hat. My magnets are completely gone it flush with front of the sprocket.

Guess start the tear down tomorrow. Again

[Guest F14CRAZY]

That's quite discouraging, a genuine GM part that's in a bad spot going bad that quickly.

Why did GM bother anyway? There's already a crankshaft position sensor...couldn't they just had went with that signal? I mean the crank is always in sync with the cam

[Ronnie]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: F14CRAZY</div><div class="ubbcode-body">That's quite discouraging, a genuine GM part that's in a bad spot going bad that quickly.

Why did GM bother anyway? There's already a crankshaft position sensor...couldn't they just had went with that signal? I mean the crank is always in sync with the cam </div></div>

I beg to differ. The camshaft only turns one revolution for every two revolutions of the crankshaft. Therefore they are not always in sync.

[Guest F14CRAZY]

That is true...what I meant was that it would seem like the signal could be divided in two...lol I dunno I'm not a powertrain engineer...in that sense

[Ronnie]

I believe I agree with what you are trying to say. One would think that the signal from the crankshaft position sensor could be used to do the same job. Maybe the camshaft position sensor is more accurate.

[D-a-n-i-e-l]

I "believe" the cam sensor is for the back up fuel/ignition system. If something happens to the crank position sensor or other components, I believe it uses the cam sensor to "limp" home.

[Guest DTerry]

Larry, how does the car run without it? I could not tell any difference in performance or economy with it in or out. Averaged 31 miles per gallon the day I picked it up in Dallas with the SES light glowing all the way home, and 31 miles per gallon when I drove back to Dallas a couple of years later after replacement. The only difference was the SES light wasn't on. I think later versions of the 3800 eliminated the camshaft position sensor. What I'm getting to is, if someone could tell me a simple way to trick the system into keeping the SES light off, I'd just leave it out next time.

At any rate, it's much easier to glue it in without disassembly. I did it years ago, and it's still there.

[Ronnie]

Instructions for replacing the magnet can be found here.

[Guest jcc3inc]

Gentlemen,

I believe the camshaft sensor is intended to provide info so that the fuel injector timing is optimal. Since the crank turns at twice the cam speed, there is no way to know cam position from the crank; you might be right on, or 180 degrees out of position.

Regards,

Jack C.

[padgett]

With port injection, timing is not really important. Ignition fires the opposing plugs at the same time so does not matter. I suspect the computer could discover quickly by switching and comparing the O2.

I *think* the series II left it off.

That said I replaced mine with the JB Weld method in 2002 and is still working fine. If replacing a timing chain I would use both methods.

[Guest imported_blazer1997]

I have noticed no difference in performance or loss of mpg when I loss the cam magnet. Padgett easy fix has helped lot of owners but being retired lot of time I replaced mine the long way.

So far light out and no codes.