Four Codes, One suspect: Crank Position Sensor?

[Tuffguy610]

Hey all,
My car is due for inspection by the end of the month. I normally have two cars but my LS1 Camaro decided to blow half a spark plug out of the drivers side head so I am down to my L36 Oldsmobile 88. The problem is that it won't pass inspection due to the SES light, and it currently has 4 codes on it. The engine is brand new, 8,000 miles on it. My uncle built it. The codes are the following:

P0420: Catalyst Efficiency Low-Bank 1 (Says bad Cat - Can't be true)
P0336: Crankshaft Position Sensor Condition (Original Unit - Possible Culprit)
P0171: Fuel Trim Bank 1 Condition (Recently Cleaned MAF, New 02 Sensor)
P1870: Transmission Component Slipping (Trans doesnt slip, but occasionally bucks while in OD+locked converter probably due to engine condition)

My question to all of you is this: do you think the crankshaft position sensor could be causing all four of these codes? The light has been on for a while, and it didnt just come on at once, it came on intermittently, then stayed on eventually. This could mean the sensor itself is bad on the Crankshaft sensor, and not that the magnet fell off of the wheel correct? I need to know so I can just pull the *dang* harmonic balancer and slap the new part on without pulling the front cover to replace a stupid magnet. Thanks for your help.

[OH2LS]

I would try the crank sensor first and clear the codes. However, you may not need a new one. I've heard of a lot of gunk getting in there and messing with the sensor's readings. Get some brake cleaner and shoot some of that in there by the sensor and have someone clear the codes and see what happens.

[93RedSled-SSE]

The crankshaft position sensor (CPS) works off of a "shutter wheel" type set up, which is on the back of the harmonic balancer. So no magnet.
Something else that can cause this is loose pins on the connector that plugs onto the Ignition Control Module (ICM). The CPS signal feeds through the ICM, so it can duplicate the problem.

Have you had the codes cleared out? They may be old ones which are stored and are not all currently "setting."

[Tuffguy610]

No I haven't cleared them. I dont have a scanner, I did the ol' AutoZone Routine. I will have to unplug the battery for a half hour and try to discharge whatever is left in the system in order to clear the codes. So everybody is telling me that the pickup magnet for the Crank Sensor is on the back of the harmonic balancer? I won't have to pull the front cover either way? This project sounds worth digging into now that I know I won't have to go back there again to pull the cover. I will check all of the connections as well. Thanks. The original sensor has almost 120,000 miles on it FYI.

[93RedSled-SSE]

Here's a picture or two
The sensor looks like this


The back of the harmonic balancer with the timing wheel attached


And it mounts here


Again, there is NO magnet for the CRANKshaft sensor. However the CAMshaft sensor does use one... just in case there is some confusion.

Read before starting:
http://www.pontiacbonnevilleclub.com/fo ... =19&t=1574
Some of the photos on this one show the sensor and also the wheel puller mounting.
http://www.pontiacbonnevilleclub.com/fo ... ncer#p4400
Somewhere, Bill Buttermore has a procedure for getting the HB nut removed when you do not have an impact wrench. Maybe he will jump in here.
There are a few tricks and tools you will need to remove the harmonic balancer.
1. Definately a wheel/gear puller that mounts via 70 to 90 mm long M6x1 bolts (3) that screw thru and into the back of the HB
2. You will likely have to use something on the flywheel to keep it from turning when removing the HB bolt.
3. If you are fortunate, you may be able to remove the HB nut with an impact. Mine wouldn't do it.
So, I used Bill B's procedure that includes socket extensions, a jack stand and breakover bar with pipel.
4. Oh, all this is done with the front right wheel and inner, lower fender cover removed.
Farce be with you,

[Mechanical Mike]

Just to clarify. There is a magnet for the crank sensor but it's not on the harmonic balancer. It's built into the middle finger of the three fingers on the crank sensor itself. If that finger were to somhow break off (we've never heard of this happening) the engine wouldn't run at all.

OH2LS is correct that gunk can build up on the crank sensor. I've even seen rusty metal particles attached to the magnetic middle finger. I don't know if that can cause a crank sensor error but if money is tight you might want to try removing the harmonic balancer & cleaning the sensor before replacing it.

[Tuffguy610]

Nah I already have the part, money isn't a problem there. I got in there today, pulled the front pass wheel, the inner fender liner, all that jazz. I even got my impact gun on that bolt and zapped it off in half a second! Things were going so good that I realized something had to go terribly wrong. Then bam! I couldn't get the right size balancer puller on the harmonic balancer to yank it off. I went to autozone and asked for a couple of them to try, and they didnt work! One was adjustable so that I could rotate the claws and try to get them to fit, but no dice. My car has a weird balancer on it. There's no threaded holes in it, just three little slits spaced equally at 120 degrees from one another. I tried to fit the jaws in there but no dice. My guess for this 1997 L36 equipped H-body is that I have to get a huge 7" jaw puller that is $50 (i'll use this thing once!) and pull it from the big rib of the belt pulley (the only place that seems able to get a grasp from). I am a little frustrated. This is an easy job but as usual things are being "a pain in the you know what". Has anybody come across a non-threaded pulley before? My friends L36 00' Firebird has a threaded one on it, totally different from mine.

[harofreak00]

The threads are deep within those holes

A puller like this, with three 6mm x 1.0mm pitch bolts and washers, bolt length is 70-90mm depending on the puller.

[Tuffguy610]

You gotta be kidding me Leave it up to me to do something stupid like that. In any case, AutoZone didn't give me the traditional style where you put the M6 x 1.00 bolts that I read about into the balancer, they just gave me two three jawed units. My friend has a bolt on type, I'll borrow it from him I guess and see. Does it take a lot of effort to pull it off? I have never done this before.

[harofreak00]

I recently just did this job as well. My local autozone doesn't carry the HB puller anyone that I have used so many times before. I have no idea why. They only carry the 3 jaw puller which is used for chrysler engines. I had to go to Advance to get the correct one.

One properly attached, it comes off super easy.

When installing the M6 bolts, make sure not to get them in to far or you will destroy the backing plate on the inside. Install them hand tight, and then just a few cranks on the ratchet. If you feel any resistance, STOP.

[Mechanical Mike]

When I did mine I borrowed a puller from Advance. NAPA was the only place I could find the 6mm x 1 pitch x 80mm screws. Get half a dozen fender washers for the screws while you're out shopping. Make sure the screws go in 3 - 4 turns before tightening them. You may have to remove the screws & screw the puller away from balancer a few times before the balancer will come off the crank.

[Tuffguy610]

Update: Talked to my uncle who built the engine. He said there's a special puller that fits in the slits of the harmonic balancer and its rare and custom as "heck". I guess the M6x1.00 80mm bolts won't fit in there (they probably won't fit by the looks of it). For some reason my 1997 H-body has a different type of harmonic balancer that doesnt have threaded holes in it?

[harofreak00]

No offense, but your Uncle is wrong. Just thread one of the bolts in there, you'll see.

[bill buttermore]

The hub of a harmonic balancer is separated from the pulley by a bonded rubber isolator. If you apply a gear puller to the pulley, you will be applying force to separate the rubber from the hub and/or the pulley. This is a bad idea. The 6mm threaded holes are in your HB, down inside the slots as others have described.

The HB puller you need is nothing special - a regular old Sears puller will work fine. You must be careful installing the bolts as the backside of the threaded holes are blinded by the interrupter rings for the CPS.

Maybe some parts of this "work in progress" will help clarify for you.
__________________________________
Draft Techinfo Article

Remove Harmonic Balancer (without impact wrench)

95 SE. others similar

Disclaimer: Working on automobiles can result in damage to property, personal injury, and/or loss of life. The author is not responsible for any losses incurred as a result of the use of these instructions. Persons using these instructions do so at their own risk!

These instructions are for those that do not have access to an impact wrench or whose impact wrench is unable to loosen the large crankshaft pulley bolt. I have used this method successfully on the most stubborn crank pulley bolts.

What you need

Hydraulic jack or car jack
Three jack stands
Harmonic balancer puller
Three M6 x 1.0 bolts and washers, 70-90mm long depending on puller
Lug wrench: ¾” socket
Splash shield sockets: 10mm, 5/16”
Crank bolt socket: six-point 15/16" or six-point 24 mm at least 1/2"-drive
Bolt about 10” long (old head bolt works swell) or big, phillips head screwdriver
Socket extensions: ½” drive extensions totaling about 24”
Handle: ½” breaker bar (stronger than a flex handle)
Cheater bars: strong pipe, or strong hollow steel stock that fits well over the breaker bar or flex handle

Bolts for the HB puller

You will probably need to buy these bolts at a hardware store or a well-stocked auto parts store. Do not assume the correct bolts will come with the puller that you buy or rent. The bolt size you need is 6mm diameter by 1.0mm per thread. Do not be tempted to substitute 1/4" fine thread (24 threads per inch) bolts. They may thread into the holes but the chances are great that you will damage the threads in the HB and cause yourself much more work. The length of the bolts depends upon your puller. For my Craftsman puller, (see Figure 1) I use 70mm bolts (measured from under the bolt head to the end of the bolt) with two hardened washers under the head of each bolt totaling 5mm in thickness. The arms on my puller are 13mm thick - this leaves 52mm of bolt past the underside of the puller arm and 42mm of bolt beyond the thickest center portion of the puller. See Figure 2.

PLAN A

Loosen lug nuts on right front wheel.
Jack up car under center of front cross member.
Place jack stands under sub-frame so front of car remains level and tires are just off the ground.
Make sure car is stable – you will be applying 600 - 800 ft-lbs of torque to the engine.
Under front of car, remove plastic splash shield with 10mm & 5/16” sockets.
Remove two plastic flywheel covers with a 10mm socket. Twist and pull the front plastic piece to remove.
Slip the big bolt or heavy screwdriver through closest hole in flex plate to the front bottom edge of engine block.
Slip the big socket fully onto the crank pulley bolt and attach the breaker bar or flex handle. Turn the engine counter-clock-wise until the bolt or screwdriver jams against engine – this will hold the crankshaft still.
Slip a cheater bar over the handle and try to break the bolt free.
Can't get the socket and handle on the bolt or can't get the bolt to break free? Go to Plan B.

PLAN B

Remove RF wheel.
Remove plastic splash shield inside fender exposing crank pulley bolt.
Set up jack stand as shown below except place the jack stand nearer to the end of the extension closest to the handle to minimize the vertical leverage when force is applied. Check that the extensions are level and in line with axis of crankshaft. See Figure 3.
Slip 4-foot cheater bar over handle somewhere around the 9 O’Clock position, so that you can firmly and safely apply your entire weight near the end of the bar.
Make sure the six-point socket fits tightly, is fully on crank bolt and the extensions are perfectly straight in line. Do not attempt this with a 12-point socket or any socket that does not fit tightly - if you do, you will likely strip the head of the bolt.
Position your body so that if the bolt breaks loose suddenly, (or one of your tools fails) you will not injure yourself with the handle, or fall and hurt yourself.
Remove any objects on the ground around you that could hurt you if you were to fall.
Pull down on the end of the cheater bar, bouncing if necessary to break crank bolt free.
Won’t come free? Get a longer cheater bar and try again.
Break the extension? Use impact extensions or rent ¾”-drive tools.
Remove crank pulley bolt.
Install 3, 6mm x 1.0 bolts and washers through puller into HB. See Figure 4.
Pull HB off


Figure 1 - Sears Harmonic Balancer Puller


Figure 2 - HB Puller bolt and washers


Figure 3 - Jack stand position


Figure 4 - HB puller attached

Thanks to the Gearheads and Administrators for their helpful suggestions.

[Tuffguy610]

Well five auto parts stores/hardware stores later, and I don't have the M6 x 1.00 x 70-90mm bolts. They all sold ones that were 50mm at the longest. I bought one and threaded it in the hole in the parking lot to see, and it wouldn't even go one turn before the head of the bolt hit the outside of the balancer. Thank god my uncle knows a shop that will lend him a specific balancer remover with those bolts on it. Then while I was in there today I noticed metallic burrs on the magnets of the A/C compressor clutch while the compressor squeaked as the engine ran. I am ten seconds away from going to the honda dealer and getting rid of this hunk.

[93RedSled-SSE]

Well five auto parts stores/hardware stores later, and I don't have the M6 x 1.00 x 70-90mm bolts. They all sold ones that were 50mm at the longest. I bought one and threaded it in the hole in the parking lot to see, and it wouldn't even go one turn before the head of the bolt hit the outside of the balancer. Thank god my uncle knows a shop that will lend him a specific balancer remover with those bolts on it. Then while I was in there today I noticed metallic burrs on the magnets of the A/C compressor clutch while the compressor squeaked as the engine ran. I am ten seconds away from going to the honda dealer and getting rid of this hunk.

Some folks have found the bolts at NAPA. I got mine at a fastener (screw & bolt) store/distributor. I, likewise, had no luck at the 3 parts stores and big hardware store.

[bill buttermore]

...They all sold ones that were 50mm at the longest. I bought one and threaded it in the hole in the parking lot to see, and it wouldn't even go one turn before the head of the bolt hit the outside of the balancer...

If you tried a 50mm bolt and could only get it to start in the threads, that makes me wonder if there is a difference in the HB itself. (Not that the HB has threaded holes for puller bolts, but how deep they are from the outside of the HB.) As you can see from the photo below showing the puller and bolt set-up that I have used on my '95, a 50mm bolt should catch more than one thread if you tried it without a puller. Could you have tried a 40mm? If you're sure you tried a 50mm, you will probably want to buy 80 or 90mm bolts as others have reported they needed.

I have a bolt supply store in my town. If you like, I can buy some and send them to you. PM me if interested.

[Tuffguy610]

Yea, I am definitely sure that the bolts need to be longer. Thanks for the offer on stopping to the store, Home Depot can special order me the bolts so I'll do that if need be. If my uncle doesnt stop by with the tool today, to Home Depot I go. I'll tackle this mess then its on to fix my P0171 code.

[Tuffguy610]

Finally got the thing replaced. I got an HB puller from my uncle that was made with M6x1.00 bolts. I really had to crank that puller to get the HB to come off. The engine even rotated a few times. When I got in there I saw that the old crank sensor had rust particles on the center magnet of it (like somebody mentioned). I didn't care I replaced the sensor anyway because I will not be going in there again just because I wanted to save 40 bucks. The outcome: no more bucking and stumbling when the torque converter locks in both third and fourth gear, seems to be a lot smoother when idling at redlights and when coming to a stop. A definite improvement. I even taped up some vacuum t-fittings to see if that would cause the P0171 code to go out so that maybe I can get this thing inspected. Thanks for everybody's help on here with this. I dont think there was one shred of untrue information on this thread.

[bill buttermore]

Glad you got it off!