beerboy

99 Suburban 350 130,000 miles 4x4

went to Kentucky and driving down the road it died. I coasted off the road and left it overnight. Next day it cranked up and took to Advanced Auto and got the code for crankshaft sensor. I replaced it in the parking lot and it wouldn't start. I put my old one back on and it started. We tried a 2nd new sensor and nothing. I put the old one on and headed for home.

I made it 20 miles and it stopped again. I changed out the old sensor to the new one and nothing so I put the old one on and it cranked and we went about 25 miles farther and it stopped and nothing got it going.

I had it towed to a shop and they are stumped. They put 2 new sensors in and still not cranking. The mechanic has an 97 Silverado so he tried his out of it and it cranked. He put the new one on his and it cranked. He traded them out again and mine wouldn't crank. His starts with all the old and new and mine only with his old.

With no logic in a repair I dont want to start a 400 mile trip with such uncertainty. ANy help would be appreciated.

Camaro 69

Doesn't make sense how the crank sensor is affecting the starter, maybe your battery is worn down?
Or maybe you're using the term "cranking" (the act of turning the engine over with the starter right before it starts running) differently?
Makes your story a little hard to follow.

delta579

As the sensor has no moving parts in it, magnetic pickup, MOST never fail. Sounds like when the wiring is moved just right a connection is made. Engine/road vibration later on is causing the connection to be lost. Check for visible signs of a bad wire. If you see any, then it time for old multi-meter and test for wire continuity.

shamrock246

When i did my crank sensor i repaced the connector also and did the connections with solder and heat shrink,are you getting good voltage to it i think 12v and a good signal back to the ECM and a good ground?check the grounds by the thermistat housing front passager side of the block and i think theres one coming off the back of the block on the passenger side

beerboy

thanks for the help, bad terminology I guess.....it will turn over but will not run...

Camaro 69

Since putting in different crank sensors has been so hit & miss, I'm willing to bet the issue isn't with the sensor at all. One thing that's constant when messing with the sensor, is you're jostling the wires. I'd look for a broken wire or connector as mentioned above.

in2pro

That is my exact same line of thinking too... I had a crank sensor error on my 97 Tahoe and it turned out to be the wire harness had come loose from its carrier and the exhaust manifold had melted it...id work fine until it got hot enough to start softening up the wires again...

beerboy

I talked to the mechanic this afternoon. The new part came with 2 shims. When he added a 3rd shim it cranked right up. Tomorrow on my next attemp to drive it home, I guess I will learn if this was the only issue.

beerboy

seems like it was a tolerance issue...I put 400 miles + on it with out any issues.


THANKS to all on here who gave suggestions.

delta579

Glad to hear it's fixed. Didn't even think of the shims, but yes it is a clearance issue.