Broken reference sensor

[Skytrooper]

Boy, I am more that a little frustrated right now. I was trying to remove the speed and reference sensors (been have trouble starting), and the one closest to the firewall broke off. I cannot get anything on it that will bite enough to pull the sensor out. I was going to take the bracket off but I cannot seem to get any allen wrench on it. My hands are shreaded at this point and I have gotten nowhere.

[SolReaver]

Hey trooper. Sorry about your luck. FWIW those things redefine Pain in the (body part). Yes. They are very difficult to get to. If you broke one off you might have to remove the bracket. I got to the allen bolt by snaking extensions and flexies up from below and the side, along the bell housing. (remove starter first) I have heard that some people reach in from the side after removing parts, including the fill tube. Others lay on the top of the engine and contort their hands like circus freaks. One unfortunate soul actually drilled his entire bracket out from above (many bad words were employed).

I went so far as to shorten an allen socket. Your methods and mileage may vary. Do what works for you.

When you say "snapped" what exactly did you snap? The bolt, the sensor itself?. A pic would help (IF you can get in there to take a picture). You may have to unbundle the wires running along the firewall and (gently ) move them aside. You may also have to move or disconnect the heater hose and valve.

In summation, "there aint no easy way out". When you get frustrated...(and you will, many times) hit it with penetrating oil and walk away. It is not going anywhere and you aren't giving up.

[Grandad#3]

Make sure you put some tape over the inspection hole on the bell housing before you drop something inside. There are all kinds of horror post about removing the bracket. Do a Search. Buy a can of KROIL as it is the best to loosen up parts. Beats WD-40 or PB Blaster hands down.

Cheers,
Larry

[Skytrooper]

The entire top of the sensor snapped off, so there is nothing to grab onto. The only thing I can see is to get the bracket off. Certainly not the best design.

[SolReaver]

You are not the first to observe that such a critical piece has been placed so far down in the dark, inaccessible area of the engine. The only counter I could come up with is that the engineers probably considered them a very low maintenance or no maintenance item. 20 to 30 years later they are going south. If your clutch need to be done...now would be a good time because the best way to deal with the buggers is during a clutch job. Otherwise you just have to fish around the drive shaft and try to get at it. Wear long sleeves and gloves as that insulation is old fiberglass and it itches like hell. IF you go at it from the top, lay down some support and padding to try and prevent crushing damage. Lastly...DO you know anyone with REALLY small hands that owes you a favor?

I have fantasized about relocating them 180 degrees and putting them on that clear spot at the bottom of the bell housing, but that would involve bell housing work and setting the ref sensor pin 180 on the flywheel. For that matter a split bell housing could make the Clutch job a breeze in comparison. Ahhh, wistful thinking. We have to deal with what we have.

[JAXTURBO]

Oh I feel your pain. Mine were not giving any trouble whatsoever, but I was trying to change as much as I could during a cylinder head job. Broke right off during what looked like it a simple R&R job. So even with the head off, I still had a heck of a time getting the busted one out. Have you tried a chisel and hammer? To try to turn the bolt. That's how I got one bolt out. I ran out of patience with the other bolt and ended up just splitting the bracket around the other bolt and removed it that way. A friend of mine gave me replacment bracket, but this is what I was looking at.

[John_AZ]

JAXTURBO,

Excellent picture!

Skytrooper,
When you search you will find many current "broken sensor" posts and then try to decide what to do with the suggestions provided.

Since your hands are schreaded already, your knuckles will begin to look like raw meat.

You cannot pound the sensor down the bell housing and hope it will magically fall out the inspection hole.

You can get to the passenger side sensor housing bolt by threading your arm between the firewall and the engine. The drivers side is your challenge. Once the bolt is stripped inside the 1 1/2" bolt will be impossible to remove.

You could just break and smash the sensor bracket and get another. Many used.

The only way to get more room is to remove the intake manifold and work from the top. A lot more of WYAIT stuff to do especially the AOS seals and vac lines.

GL
John_AZ
1988 924S + 1987 924S

[thekidd]

I have been working in the sensor area alot. To break the bracket bolts free took some time, and patience. There isnt alot of room down there, so you may want to take the manifold off (and the fuel rail, air box, AFM, throttle body, oil fill tube, and maybe 1 or 2 other small things) to give yourself the most acessability to the sensor bracket. Be very carefull not to strip either of the allen head bolts (Im the guy that used a right angle drill on a car) If you really dont want to take any of that stuff off, there is an AC dryer, I think thats what it is) that is in the way that takes up some space. It is connected to a hose fromt he engine, then the dryer (looks like a black beer can) then another hose that goes into the fire wall. Loosen the hose with a flat head, and push everything out of the way. Should give you enough room to get at and loosen the pass. side pivot bolt. The drivers side bolt is alot harder to see and to move the allen bolt, this is the one I striped. I hope that this helps.

[SolReaver]

So..Nobody else comes in from below and behind? Always from on top? What are you all Missionaries?

Whatever you do... Make sure you have prepped the bolt by using Kroil, PB blaster, or whatever. Try "waking" the bolts and the bracket by tapping on them a bit. Clean out the hex sockets in the bolt thoroughly with solvent and Q tips if you have to to make sure whatever allen wrench you get in there sits well before applying torque. Once you get the bolts out think about replacing the hardware.

[Skytrooper]

JAX... That is exactly the same condition I have !

Thanks for the suggestions guys, now I just have to put my hamburger hands back in and give it the college try. I had to stop yesterday as I was seriously considering setting the car on fire...it was a bad day. I am better and thinking more clearly now and realize that I just have to figure out how to get the darn thing out.

[Skytrooper]

Originally Posted by John_AZ

JAXTURBO,
You could just break and smash the sensor bracket and get another. Many used.
GL
John_AZ
1988 924S + 1987 924S

That is what I finally had to do. I bought an insanely long vise grip at Harbor Freight, but just couldn't get enough of a bite on the sensor. I managed to get the pivot bolt out but the lock bolt wouldn't move and I was afraid that I would strip the head if I kept at it. I started gently prying hoping that might reduce the torque on the lock bolt....I was wrong, I finally just wiggled the bracket until it broke. With a little extra room I was finally able to get the lock bolt to break torque...of course it had that special thread lock known as corrosion helping keep it tight. Tomorrow I will start working on installing the new bracket and testing the sensors...prior to installation.

Thanks

[John_AZ]

You saved your body and many hours of frustration.

It is suggested to use hex head bolts instead of the pan head 6mm on the sensor bracket.

John_AZ

[Skytrooper]

I just happen to have a set of those waiting with the other bracket and sensors. Buying that spare engine certainly has been well worth it.

[JAXTURBO]

Originally Posted by Skytrooper

I just happen to have a set of those waiting with the other bracket and sensors. Buying that spare engine certainly has been well worth it.

Alright. Good for you. Upon reinstallation remember you have to set the gap. I beleive it was on Clark's Garage where I read the washer trick. Find a washer that is the same thickness as the required gap. Glue that to the bottom of an old sensor. Use good metal bond adhesive, and allow for proper cure time... don't want it to fall off. Install bracket (leave loose), install sensor (with glued on washer), pivot bracket until contact is made with flywheel. Tighten bracket, replace sensor with new one. Now don't do what I did... switch the sensor connections. They both are similar, but cannot be reversed. Soon you will have this finished product.

[John_AZ]

I also put a little anti sieze on the sensor bracket bolts. Some use it on the sensor as well with no problems.

GL
John_AZ

[JAXTURBO]

Originally Posted by John_AZ

I also put a little anti sieze on the sensor bracket bolts. Some use it on the sensor as well with no problems.

GL
John_AZ

+1 on the anti sieze. Good point John!

[TSNAPCRACKLEPOP]

the human always wins!! There sure were a lot of stuck sensor bolts this year!! and every time, the human won.

[Skytrooper]

My new sensor should arrive Monday. Hopefully I will have a running 944 again soon !

[SolReaver]

Instead of the regular washer on a dummy sensor to get the correct gap, Glue a plastic washer the correct thickness to the bottom of the sensor and tighten it down. The plastic might get chewed up and fall off, SO what? The sensor is in there properly set with one step. I used low grade locktite on both sides of the washers, and anti sieze on the threads. X2 on the hex nuts to hold in the sensors. Think about refreshing the connectors while you are here.

[thekidd]

None mentioned the BMW 5 series sensors? I dont know the exact details of which one to erder, but the BMW 5 series sensor also works on the 944's. People have said that the $70 one is the exact same thing, just longer wiring, but I have only seen one for $90, and I think that is just for one. Anybody know the exact one and details on this?