Crank Sensor On The 8.1

Burbman · August 19, 2007

Looks like from the service manual I need to jack up the truck and get this from the bottom. Anybody change theirs? Big job?

Haulin' 8.1 · August 19, 2007

It's not that bad. It's fastened by a 10mm bolt. A stubby 10mm gear wrench is perfect otherwise you'll do a lot of little twists. You should let the exhaust cool down due to proximity. A large screwdriver or pry-bar will be helpful in tapping up a stubborn fitting old sensor as will some penetrating lube. Whatever you do don't force it as it's long and can break off with some of it still in the engine. You'll find it on the back side of the drivers side cylinder head going down into the bell housing flange. It has a two wire connector. There's only room for one hand up there so have the truck raised up so you can get situated underneath it with a good grip on the wrench. The first time I did one it took about 40 minutes just figuring out what I was doing the next time it was more like 15.

Vernon

Russ Huelle · August 20, 2007

I just did mine about a month ago. I have 6in lift on mine so I was able to pull the inner fender and get at it that way. Took me about 1 hour. The ratching box wrench is a must. Doing it myself saved me about $550. I paid $40 for the part. Good luck.

Burbman · August 20, 2007

Thanks for the tips, guys! I did the cam sensor a while ago, but now at 85K I have the classic symptoms of crank sensor failure. I figure I'm overdue since most haven't made it this far. I'm ordering the part tomorrow and will give it a try.

Burbman · August 20, 2007

One more question, the service manual says I need to do a crank re-learn after installing the new sensor, Did you guys do that, or can I skip that?

Russ Huelle · August 20, 2007

I didn't do one when I did mine. I haven't had an issues with it, no warning lights or any problems.

Haulin' 8.1 · August 21, 2007

You don't have to do it in order to drive and operate the truck, and most people won't think anything about it. But once you do it you'll notice it starts, runs, accels a little better. Like a tune up. Some times it's a big difference others not much. It depends on how far off the computers sample and the actual signal are from each other. I do one with every tune up I perform and it's crazy how it will instantly idle smoother afterwards.

Vernon

Burbman · August 21, 2007

I'm thinking it's a good idea. Do you need a Tech II scanner to do that or will any garden variety be able to access that feature?

Haulin' 8.1 · August 21, 2007

I use a OTC Genesis. My Snap-On doesn't have software past 2000 but I'm sure a current one would.

Vernon

Burbman · August 22, 2007

Vernon, thanks for the info. Today I changed the seat belt tensioner in the passenger seat...what a pin, had to take the whole seat cover off, but went back together OK.