crank shaft sensor damage
 

after replacing a timing cover gasket when I start the motor it damages the crankshaft sensor . why?

My local parts store gave me a crank sensor that was way toooo long.

Their book said it was the right one, but it wasn't. Their book was wrong. I went to a Chevy dealer and got the right one.

Did you use the same crank sensor and cover or were they changed? I think that plastic cover says on it to not re-use it for some reason.

I had the exact same problem with mine, GM dealer sells shims to be installed on the crank sensor to cure the problem they were only $10 for 2 here in Canada.

thanks guys for the info I will try to put this to good use

To all:

1997 Chevrolet Blazer Emissions Problems | Gas Savings Formula

Apparently the plastic timing chain cover WARPS over time causing a drive ability / emission issue. And this poor guys cover warped so bad the crank hit his sensor.

All be aware.....

Yeah shims, were there any shims on the old CKP? They can be easy to miss because they're less than wafer thin.
Also does the CKP has witness marks? Are you sure it's being impacted?

No I am not a 100% sure its being impacted.There is what appears to be scratches and wear marks on the end of the sensor

no shims

new cover too

If there ar scratches then those are the "witnes marks" I was mentioning. Go to GM or rock auto etc & get a pair of shims. I'd install then 1 at a time & see if that corrects the issue. They're cheap, probably under $10.