Crank Sensor Issues?

[Nick Micale]

In the past few years I have had issues with crank sensors and brackets that were never encountered before?

The first issue was with fitment and configuration of the bracket, as it would allow the ring to interfere with the plastic sensor. To fix this issue, I would need to grind the bracket to allow proper alignment.

More recently I have had issues with the crank sensor slots being out of tolerance, and in a few cases the ring would contact the side of the slot and actually remove some plastic and even slice the side of the slot. I chalked this up to my eyes getting older and maybe mis-aligned the sensor?

After 25+ years I finally purchased a factory crank setting tool for a lot less than the original price of $700-800.

So I of course wanted to check out my new "toy", so I tried it on a spare engine with a crank sensor and it would not pass through the slots as it should? A new sensor/bracket out of the box was installed and still would not pass through the slots?

The third new sensor, different brand, worked fine as did a used one.

With a close inspection of the bad sensors, it was apparent that the slots were not parallel, and not wide enough for the ring to pass w/o damaging the sensor.

I do not know if the "bad" parts were made off-shore or not, but this is another case of replacement parts that are different physically from original.

At least now I have the ability of checking different brands, and not trashing a new, expensive part.

 

[John Larkin]

I used some pieces of cardboard from the box mine came in as a gauge on each side of the reluctor ring. All 3 vanes passed through my Delco sensor as close to equally as I would expect. Nothing is perfect it seems.

 

[Boost231]

sweet tool didnt even know they had one. I guess you will be addind this to the list of things to check on a fresh engine build.

 

[Ktbregal]

That's awesome. Are these tools still available?

 

[GNVenom]

GM discontinued the bracket, so there are several aftermarket companies which produce that bracket. And, several manufacturers which reproduce the sensor. I have found considerable variations between the different designs, and yes, the height varies as well.

This would cause interference with the interrupter ring and definite fitment issues as you described.

Always good to check and compare the replacement part with the original piece.

 

[Chuck Leeper]

Not sure mine is an original part. [87T, 59K on the clock], I found the sensor was loose in the brkt.
Took it off, cleaned it, checked the ring, reassembled. Would not tighten up. Back off, changed the sensor. Tightened up, but still not tight enuf. Replaced the assy, and then the brkt had to be spaced out w/ AN washers, as the brkt hit the timing cover,[Original cover], to allow the air gap to be set.
Appears the plastic spacer strips were a ??
Got things tite, adjusted, working. While still in the shop, installing PL, etc, the engine took a ...
Took it out, sensor is LOOSE! WTF is this about?? More cheap junk?
Engine at the machine shop.....

 

[Mike T]

I ran into the depth problem about 8 years ago on my current engine. The problem was even worse because the early BHJ balancer/damper set a little closer to the timing cover than the stock balancer.

 

[GNVenom]

Here's some tech info:

http://www.installationinstructions.com/FYI/cranksensortech.pdf

and

http://www.installationinstructions.com/FYI/crank_sensor_info.pdf

It explains the difference between the crank sensor brackets and how they secure the sensor itself.

 

[TurboBuRick]

I ran into the depth problem about 8 years ago on my current engine. The problem was even worse because the early BHJ balancer/damper set a little closer to the timing cover than the stock balancer.

I've run into that problem before. In every case, the oil slinger was missing.

 

[TurboBuRick]

A lot of drivability problems can be traced back to the crank sensor. I've done some playing with gap settings in the past and have found that the tighter the sensor is to the outside of the wheel, the better the car runs. Mainly smooths out low rpm trouble spots.

My $.02

 

[Mike T]

I've run into that problem before. In every case, the oil slinger was missing.

I bought this one used so who knows how old it really is or what's been done to it. The motor is apart now so I was able to confirm it's the balancer comparing it to the stock unit. The slinger is definitely in place but this time I added 1 GM spacer for a little additional clearance.

 

[TurboWh1]

I experienced the same issues with a couple different engines. Purchased aftermarket and noticed considerable differences in the size of the sensor and the bracket as well. I ended up using the original bracket and went to GM to purchase the sensor. That was a few years ago, I'm not sure if GM has discontinued the sensor only....

 

[Ktbregal]

Correct me if I am wrong but I remember replacing a sensor on a 1988 Park Avenue 3800 and it came with a plastic alignment tool. I wonder if they ever made any for our cars?

 

[GNRick]

Couple years ago my car was sputtering at about 40 mph in town. If I accelerated it smoothed out. It was an original style crank sensor. Put a new after market sensor on and that fixed it. I just bolted it on. I don't recall any way to adjust the gap. Car runs fine. Did I just get lucky?

 

[TurboWh1]

Couple years ago my car was sputtering at about 40 mph in town. If I accelerated it smoothed out. It was an original style crank sensor. Put a new after market sensor on and that fixed it. I just bolted it on. I don't recall any way to adjust the gap. Car runs fine. Did I just get lucky?

I guess I'd rather be lucky than good! If you split the difference in gap you will be good. I tried the feeler gauge method to try to get it exact. I personally had better luck eye balling it up

 

[Nick Micale]

So I brought the 2 new crank sensors off my shelf back to the auto parts store I deal with along with my new tool to show them the slots were off as the tool would not pass through the slots.

I had them order a different brand yesterday which turned out to be Airtex unit. Never used one of them before, but I was suprised when the slots lined up perfect on the setting tool!

Just to clarify, this is NOT a setting or adjustment issue with the crank sensor itself.

It is that the slot on the new sensor [some of them at least?] for the interrupter ring is way off enough so the ring will make contact with the plastic on the first turn and trash the sensor, or in my case 2 new sensors before I figured out the problem was the crank sensors?

 

[David Husek]

In the past few years I have had issues with crank sensors and brackets that were never encountered before?

The first issue was with fitment and configuration of the bracket, as it would allow the ring to interfere with the plastic sensor. To fix this issue, I would need to grind the bracket to allow proper alignment.

More recently I have had issues with the crank sensor slots being out of tolerance, and in a few cases the ring would contact the side of the slot and actually remove some plastic and even slice the side of the slot. I chalked this up to my eyes getting older and maybe mis-aligned the sensor?

After 25+ years I finally purchased a factory crank setting tool for a lot less than the original price of $700-800.

So I of course wanted to check out my new "toy", so I tried it on a spare engine with a crank sensor and it would not pass through the slots as it should? A new sensor/bracket out of the box was installed and still would not pass through the slots?

The third new sensor, different brand, worked fine as did a used one.

With a close inspection of the bad sensors, it was apparent that the slots were not parallel, and not wide enough for the ring to pass w/o damaging the sensor.

I do not know if the "bad" parts were made off-shore or not, but this is another case of replacement parts that are different physically from original.

At least now I have the ability of checking different brands, and not trashing a new, expensive part.

Nick, a few years back I purchased a lot of parts that came with a few crank sensors in a zip lock bag. No manufacture to reference. None of these sensors would pass thru my crankshaft sensor adjuster. I tossed them out as cost was almost nothing for them. I use Delco parts mostly and I also have never seen this before or again to your post. Mine looked like the mold that made them was damaged/leaking. With the balancer removed the tool definitely makes installing and aligning the sensor easy. It is handy to check that the interrupter ring is true also.

 

[INEEDAGN]

IMO the crank sensor is the ONE electrical item on the car that's cheap enough from gm to just buy the gm part. Run the part number on eBay if the dealer is high

 

[Nick Micale]

When I looking on-line for crank sensors, I found this information from the supplier:

"Note: ACDelco partners with other manufacturers to supply the parts your car was originally built with. This product is in an ACDelco package, however the part may have been manufactured by an independent ACDelco supplier and could have a different color or shape than the product image above."

Before Delco went off-shore for many of their parts, I used their parts exclusively. However over the recent years I have had better results with other brands.

 

[NY Twin Turbo]

Hey guys, help me out a second. If I remember correctly you could use either of the 2 slots, right?
If this is the case, which one do you prefer? The one closest to the harness plug or the one on the end?
Also, if one is scuffed/damaged from a rub can you use the other?