Thread: 3.8l super charged tach loss

It's your crank sensor....I never had any codes or ANYTHING at all.....would randomely lose the tach and randomely wouldn't start.

Originally Posted by 4THGENCAMAROFAN

It's your crank sensor....I never had any codes or ANYTHING at all.....would randomely lose the tach and randomely wouldn't start.

You haven't check good enough. cause here's your problem

X2 or 3 here. LOL

Its your crank shaft positioning sensor. The sensor is located on the back side of your harmonic balancer pulley, and bolted to the front engine cover. These are the warning signs of the sensor going out, or becoming weak.

You can get a replacement from any local auto parts store. They are like $25.00 or $30.00.

The chore is to remove the balancer and the bolt. The bolt will be VERY tough to get out if its never been removed. You WILL need a impact gun to remove it. It will take a while with the impact, but it will come off. Your balancer puller, you can use a regular puller, but you will have to put a DEEP socket in the hole for the crank bolt, such as like a 1/4 drive, 12mm or something. This will act as a spacer because the puller will bottom out before it even starts pulling. I use a old nut that fits down in there too for the puller to ride/press on so it does not hurt my socket. The three bolts you will need for the puller to work wont come in ANY kit. You will have to buy the bolts, and some washers most likely and make sure you get Grade8 bolts. They are like a 1/4 bolt and fine thread, and have to be so long.

PM me if you want the size, I can go get that for you out in the garage, or search on here, because I have posted it before.

The balancer is off, the sensor unplugged and the cover removed, two bolts will remove the sensor, install new and then add more Teflon PASTE to the bolt threads before they go back in. These do not go into waster jackets, but all the front cover bolts have sealer on the threads, so all the bolts get sealer on the threads when they go back in if I am doing the job.

Wipe a little engine oil on the balancer end that goes into the front seal and CAREFULLY set it on the end of the crank, and turn it till you fell it catch the woodruf key on the crank and then push it on a little to hold it.

The crank bolt is a TTY (torque to yield) and they say its "not reusable" but I have reused mine countless times. Thats a big fu@king bolt, nothing is going to happen to it. I will put some RTV on the BACK SIDE if the head of the bolt, you will see some orange sealer already there, clean that off, and add some new stuff. The threads of the bolt, I will wipe a little ARP assembly lube on the threads, or if you don't have any of that, you can use some anti seize. Worse case, add a little engine oil as a last resort.

HAND start the bolt, and thread it in as far as you can by hand, and THEN use the impact. Yup...seen some cross thread that bolt before.

Impact that bolt on, and when it stops turning, let the compressor catch up/built up pressure and shut off, and then hit it again with the impact cause it will turn some more. When it doesn't turn any more, your done.

The bolt should be like 111 ft. lbs + 96* or something like that. Pretty impossible to get the degrees. I have been installing them with a impact like this as far and as hard as I can, and never had an issue. Others too.

The job takes me about 25-30 minutes tops from start to finish when I do them.

If a shop was going to do this for you, they would probably charge you for a full hour or two for labor + marked up prices on the part. Not unheard of that some paid over $150.00 to have that sensor installed.

A cold Mt. Dew while I work is payment enough for me usually.

~F~

You don't have to use an impact. I've yet to require one on a 3800 . Simplest way I've found is to use a set of vise grips and clamp them on the flywheel (not on the teeth). Then use a breaker bar with extension so it sticks out past the fender. I also put a block under the extension for support . I use a little 18 inch bar and haven't had a problem. But then again I'm big enough and strong enough to do it. Just as easy to get it back on too. And if u have a decent impact like I do its easy to over tighten the the bolt and rip the threads right out of The crank so please don't just keep tightening till it won't go any farther like stated. Ingersal rand and 135psi shop air can rip those threads right off if they're weak at all

I don't use one. I prefer hand tools with everything possible, too easy to mess stuff up with air and power tools. Plus it only takes a couple minutes to get it off.

Never needed an impact for anything on a 3800 engine. Bout the only crank bolt I've encountered requiring an impact was a Honda civic. Actually just realised I sold that impact about 6months ago. Lol I forgot about that.

Don't NEED an impact...I never used one to break it loose. I just used a breaker bar to get mine broke loose then used an impact to speed up the process.

The bolts to remove the balancer are 1/4-28 IIRC.

And yes, start the crank bolt by hand. Don't risk stripping out the thread when all it takes is literally 2 turns by hand to make sure it's threading on correctly. Also I reused mine...I didn't torque it but I did use some RTV on it.

Nice time Racingfool....my first time doing it only took about an hour having NO idea what I was doing other than reading the write up.