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crank position sensor

V

vermsta

New member
I got a customer that is having some issues with her car shutting off while she is driving, and I told her I would ask you guys your opinion so we could get to the bottom of this. Basically here is what's happening. Her car runs great, but once in a blue moon it will shut off while she is driving and she will have to pull over come to a stop and she says it will start back up and drive fine. I'm thinking it is ignition related, like a bad ignition switch, or bad sesnor giving a rpm signal like cam or crank sensor. The problem is so intermittent that it is almost impossible to diagnose, since it's only happened 3 times in a month. She has however got a crank shaft position sensor code from time to time. I was just wondering if anyone has had similair complaints due to a bad crank sensor, cuz I'm assuming to change this it's a big job and I don't want to make her spend the money if it isn't going to fix the problem.
 


It's hardly a big job. Remove belts, crank bolt, and the balancer. Maybe an hours worth of work.

But it does sound like the crank sensor. Since the ignition system rarely goes bad.
 
When mine went bad it didn't stall the engine except for a couple times over the 2 years or so it was bad. I would just put it in neutral and start it back up without pulling over.
 
I did have a case one time with a friend, where the connector that runs to the cam and crank sensor had a pin bent over. It was just enough that road or engine vibrations would cause it to throw a crank sensor code. We changed the sensor, and it still did it.....so you might go ahead and check the connector and harness just to rule that out.
 
what kind of car is it? is it a grand prix with the 3.8 or something else... while it does sound like it could indeed be related to the CPS, knowing what vehicle it is might help point to other items that might be more of a known problem with a specific vehicle.
 
I also had an issue with the harness that connects it to the module was shorted (touch the harness and the car ran different)
 


I didn't even realize I didn't say what engine this was and vehicle. It's a 97 grand prix supercharged 3.8L. The crank angle sensor came back again. I'll take a look at the connection when it comes in tommorow. I guess I'll just start there and hope that by fixing that the problem goes away. Thanks for the input guys.
 
The balancer threads are unique and not standard size. I did a write up in the How To section on how to pull the balancer. I believe the thread is 1/4-28 or some odd size like that.
 
SyntheticShield said:
The balancer threads are unique and not standard size. I did a write up in the How To section on how to pull the balancer. I believe the thread is 1/4-28 or some odd size like that.
Click to expand...

FWIW, 1/4-28 is a standard fine thread screw thread. Any hardware store should have them.
 


I'm looking at it right here....M6 and 65mm long....approx 3 inches or so long.

A 1/4 will not thread into the balancer correctly and you run the risk of pulling the threads and crossthreading it.

It could just be my engine, so take that with a grain of salt. if the 1/4 threads in without binding up, go for it....otherwise it could be a different size.

Go with what works.
 
Reptile said:
I'm looking at it right here....M6 and 65mm long....approx 3 inches or so long.
Click to expand...

I have no idea what bolt is in the balancer. Just offering my advice on bolts.

M6 x 65 is not a common bolt size. What you probably have is an M6 x 1 bolt that is 65mm long. M6 means the bolt is a ANSI Metric Bolt, diameter 6mm (approx 15/64", almost 1/4"). The 1 is for the pitch of the thread. It is 1 mm from the peak of one thread to the peak of the next. Or, the thread increases 1 mm for one revolution of the screw. The 65mm that you mention is probably the length of the screw. 65mm is a little over 2.5". But to say that you used an M6 bolt is incomplete as there can be different thread pitches for an M6 bolt. As I said, M6 x 1 is a common bolt.

Hope this helps! :)
 
Thanks, that's pretty much what I meant. LOL

6m bolt, 65mm long, thread pitch...who knows, but it works for me!

/brainfart
 
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