8.1 workhorse crankshaft sensor

[CamJam1]

My understanding is that the part was redesigned somewhere around 2002-03, (perhaps due to a high failure rate?). Most of the problems I've seen in GM 8.1 forums appears to be 2003 or earlier, so I'm hopeful that my 2004 won't ever have this issue. Still, a spare can't hurt if you have an extra $100 laying around.

Delphi, Delco, AC, Saginaw, Packard Electric , Allison, Detroit Diesel and probably others were all GM companies at one time. The Government made them sell a lot of those companies off as part of the 2008-09 bailout. I think only ACDelco is still part of GM.

EDIT: I see now that the original CPS was subject to a recall, 2001 model year only. https://static.nhtsa.gov/odi/rcl/200...7V521-7609.pdf

Part no. 12575172 is the correct replacement part, according to the recall.

[yeloduster]

I hope that the part in my 8.1L is one that has the redesigned CPS. If that is the case I may never no if the Delphi part I bought is a good one. Maybe my original will last as long as I need it to.

[VanDiemen23]

Holy cow. In the early 2000s the company that makes these for most of the OEMs had some kind of either design or manufacturing problem. The sensor is the same but is re-packaged (housing and connector) for each OEM. I had a 01 Nissan Altima die followed a few weeks later by my 01 GMC 8.1. The same tow guy came and got both of them and he said he was towing 5 cars/day for the same problem, virtually every OEM.

Yes, the part was re-designed. I don't know the exact cutoff dates, but I'd say that if your ride was made after 03 you're pretty safe.

To the best of my knowledge they don't get intermittent and cause strange engine "misses". With the 8.1 when they go the engine will not start PERIOD. IIRC, it won't even crank. if the motor can't figure out where the crank is WRT the camshaft it figures that the timing chain has broken and for warranty purposes, doesn't want to bend your valves. It doesn't know when to spray the fuel and when to send the spark. It checks all of these things in that short period of time between turning the key and cranking (power up BIT).

My 8.1 has a "stumble" at idle that I bet a lot of folks think is a misfire. After years of wondering I think that the CPU leans the mix out until it stumbles, and then richens it up, and this cycle repeats. It correlates to what I see on the tach at idle and can hear as well as feel.

[Mark_K5LXP]

Originally Posted by VanDiemen23

I think that the CPU leans the mix out until it stumbles, and then richens it up, and this cycle repeats.

If you hook up an OBD monitor you can watch your O2 sensors, as well as short term trim to see if the stumble coincides with the rich or lean parts of the lambda cycle. The last time I experienced this symptom I WAG'd it and replaced the wires and plugs, and the idle markedly improved. I think in the interest of emissions the timing and mixture are right on the ragged edge and even slight changes in any part of the mixture or ignition can manifest in observable miss or stumble. Off idle/operating differences are overcome.

Mark B.
Albuquerque, NM

[yeloduster]

I have a Torque Pro monitor that shows the same kind of information the ScanGauge does. It shows misfires. I think that if your engine starts exhibiting the symptoms of a failing CPS the monitor will show random misfires on all cylinders.

It might be a fairly conclusive test.

I carry a camshaft sensor with me too just in case!

[Trek8288]

I will give you a thought;

Yes, I do our best to obtain OEM and/or high quality parts.

It is my experience, or bad experience depending on how you wish to look at it. My MH heater went out, determined it was the resistor in the circuit board. Heard Dinosaur Electronics was great. Purchased one, installed it 2 years ago, excellent product. Now my circuit board in the back of the refrigerator failed. Called Them, they referred me to their vendor and provided me with the part number, were awesome to talk to; purchased and installed it great, USA product, great people.
Dinosaur Electronics informed me that Amazon is selling counterfiet using their name, but they are NOT Dinosaur Electronics period.

I purchased a pump from Amazon for my water tank, wanted to find the same make and part number, found it on Amazon. Installed it, junk, compared the one I took out, not the sam but had the same name on it, counterfiet!

The crank sensor I removed was an Amazon counterfiet. Junk.

I do purchase from Amazon and actually alot. However, I now am very skeptical of those purchases and know they are most likely to be counterfiet.

NO mechanical or electrical parts are purchased from them

FYI

The Sensor I purchased was from a GM Dealer via the phone and came in the AC Delco package.

[CamJam1]

AC Delco does have an email address on their website that you can use for determining whether something you've bought is real or counterfeit. I purchased an ACDelco oil filter off Amazon last year that looked to me like it might be fake, as it looked to be using thinner metal than the old filter and some of the writing on the box was Korean. It was also listed at a very cheap price... less than $5 as I recall. They asked me to send photos, including a close up of the dot matrix style code imprinted on the part, and determined that the filter was genuine.

[Trek8288]

True, Sad but true.
US manufactures are getting their parts from China, India, etc.
Question is; Are these now overseas cheap made parts as good as they once were? Better? worse?