Experiences with an HES

[snookers]

For a while now, every now and then my 1100RT would stall out. I was able to restart the bike so I was shucking it off to bad gas or some other anomoly. Two weeks ago the bike died......wouldn't restart .....so I did a number of roadside checks with the electrics......checked fuses, relays, and listened for a running fuel pump when the key was turned to the ON position. After approx. an hour on the roadside, an attempt to restart the bike was succesful.....so I rode it home. For the next week and a half.....and many rides later there were no issues with the bike. Well as fate would have it, the bike finally quit when my bride and I were on a roadtrip. At this time I knew what it was......or at least suspected what the problem was. So now it was a tow home.....this bike wouldn't restart. The only saving grace for me was the fact that a brand new HES from BeemerBoneyard was onroute to me.....the HES to my knowledge was never changed out by the previous owner so having one ready to go was the idea. Seems the original wanted to go before I could swap it out.
I installed the new HES and now the bike actually feels more responsive to the throttle. Not sure if its my imagination.


Preparing for the long ride home



Teardown to retrieve the HES



Broken down insulation

 

[james1300]

OK, I'll Bite...

What the heck is a HES? Where is it located? What is it supposed to do?

 

[snookers]

HALL EFFECT SENSOR

lt is the ignition trigger which is located behind the crankshft pulley behind the black plastic cover at the front of the engine case

 

[roger 04 rt]

How often does this happen on R1150s?

 

[pauls1150]

Allegedly they upgraded the insulation in the 1150s... only time will tell; maybe set up a survey?

 

[gsaddict]

Allegedly they upgraded the insulation in the 1150s... only time will tell; maybe set up a survey?

Only after late '02 I believe.
I have rebuilt plenty early 1150 ones.

 

[bluehole]

Is the HES going to fail sooner or later? Is it a random sort of thing? Wondering if I should address this item during the winter.

 

[roger 04 rt]

Only after late '02 I believe.
I have rebuilt plenty early 1150 ones.

That's what I heard but Mike from Beemer Boneyard says he sees all years ordering replacements. Makes me wonder if that's a precaution or if the reason for fewer 2004 failures is merely because they're that much newer.

 

[gsaddict]

Is the HES going to fail sooner or later? Is it a random sort of thing? Wondering if I should address this item during the winter.

Its a matter of heat cycles ie: the higher the mileage the more prone to failure.
Usually around 60,00 miles +
The insulation gets brittle and starts cracking near the motor

 

[pauls1150]

My '04 is certainly past that - probably time for a careful inspection!
Thanks for the heads-up.

 

[happy wanderer]

The problem is that you cannot see the damage happening because it is inside the wire sheathing. Insufficient heat resistant wire was used to make the short harness going to the sensors and the damage occurs inside of it close to where the small clamp holds it onto the hall sensor plate. You only discover the damage by cutting the harness open at this point.

A very crispy hardened outer cable layer could be a clue but even then does not necessarily confirm what is inside. It's a very hot area of the motor up there.

Here's a failed HES sensor wiring harness from my former 96 RT with about 47K kms on it. It was ridden in the rain a lot. The inside wire insulation has been cooked and crumbling to bits. Bike finally refused to start at all exactly the same way the OP's problem happened.

 

[scott.lambert]

The problem is that you cannot see the damage happening because it is inside the wire sheathing. Insufficient heat resistant wire was used to make the short harness going to the sensors and the damage occurs inside of it close to where the small clamp holds it onto the hall sensor plate. You only discover the damage by cutting the harness open at this point.

A very crispy hardened outer cable layer could be a clue but even then does not necessarily confirm what is inside. It's a very hot area of the motor up there.

Here's a failed HES sensor wiring harness from my former 96 RT with about 47K kms on it. It was ridden in the rain a lot. The inside wire insulation has been cooked and crumbling to bits. Bike finally refused to start at all exactly the same way the OP's problem happened.

I have one that looks almost exactly like that. Haven't got around to fixing it, which I should do since I put a new one back on just like it.
It's only a matter of time before it fails again.
If only they had made the leads a little longer coming out of the sensors so the vinyl covered wire wouldn't start until open air.

 

[scott.lambert]

Teardown to retrieve the HES

View attachment 41539

That's a nice photo. I'm usually too sweaty and mad by this point to hold a camera.

 

[happy wanderer]

I have one that looks almost exactly like that. Haven't got around to fixing it, which I should do since I put a new one back on just like it.
It's only a matter of time before it fails again.
If only they had made the leads a little longer coming out of the sensors so the vinyl covered wire wouldn't start until open air.

If they had used the correct temperature rated wire it never would have been a problem. I don't think BMW ever acknowledged this design or design materials failure but they all fail eventually and some much sooner than others depending on climate etc.

Great Hall Sensor Tech Article by Dana Hager here:
http://advwisdom.hogranch.com/Wisdom/oilhead_hall_sensors.pdf

The original Honeywell sensors are no longer available unfortunately but there are suitable replacements out there for more money I believe. Usually they are fine and the wiring is the only problem.

 

[dieselyoda]

What I want to know was how did Snookers know for sure?

My 97 R1100RT started to run like crap a month or two ago. I agonized over the cause from bad spark plug to a crappy injector. Checked codes, always got the BDC HES code, checked it with an ohm meter, voltage cranking the engine, frequency and an oscilloscope. I could never say for any certainty that the HES was the problem.

Sixty bucks got me a used off of Ebay, installed, problem gone. Took the old one apart, looked OK, not as good as the one I installed. There is a procedure for checking Hall Effect Sensors, they are used in a pile of applications, checked mine, passed fine.

What I want to know Snookers is how you were so confidant? Gut instinct still remains a valid troubleshooting tool.

Better question: How did you set the timing? Dynamically or make the special tool described on Advrider? Eyeball it and set the timing when the engine sounded happy?

 

[snookers]

Deisel yoda.....how did I know for sure you ask?

Actually....for me it was a process of elimination....the age of the bike and being the second owner with knowledge of its service history......I have a new fuel pump in the tank......and could hear it running when the key was turned to the ON position.....so fuel delivery was most likely not an issue......
secondly.....the bike had been cutting out on me periodically.....with no apparent reason.....thirdly and most importantly......I have been reading posts on this site for quite some time now and figured it was just a matter of time before it was my turn..
BTW.....I wouldn't consider anything else but a new part for replacement

 

[dieselyoda]

You just knew, I love it.

I could have guessed a ton of other stuff and some not fun to consider. My first thought would be the ignition coil based on heat. I even went so far as to cook my ECM in the oven to see if it could be an issue. I wasn't concerned about a frozen ECM, who'd get on a bike at -40C? In my experience, frozen ECM's could make you crazy and in the shop, the damn crap ran fine.

Good for you. You kept it simple and didn't second guess yourself. That's awesome to hear.

As to new parts, I could tell stories......once, we had to lift the cab off a zoom-boom to change the alternator, about 15 hours R&R. Boosted the batteries, went dead quick. Of course, no charge from this $500.00 new alternator. Customer is now climbing up my @#%&*$ and the alternator rep, says, "Yeah, for sure, the alternator has warranty but the labor is yours." This was a field service call and redoing the job probably didn't cover the cost of fuel, much less that I couldn't go to another job. It's a familiar story in my world.

A nice story and if you ever hit the Prairies.................

 

[Rinty]

I recall a post a while back by a member who replaced the HES wiring with some special aircraft stuff.

Given the difficulty of diagnosing this, it seems to me that freshening /upgrading the HES wiring could be a preventative maintenance item, at an appropriate mileage.

 

[gsaddict]

Teflon aircraft wire and hi temp heatshrink is the fix.
Hall sensors should be replaced if you really want to 0 time.
Trouble is, the Hall sensors are obsolete now. Honeywell (Airpax) 2AV54 are no longer made.
Hard, if not impossible to find

 

[happy wanderer]

I've been running one of GSAddict's professionally re-wired HES plates (and he _is_ a pro! ;-)) in my RT for many thousands of miles now with zero issues. The wiring on mine was cooked hard but not cracked open yet at only 23,000 miles or so. Nevertheless I decided to upgrade it _before_ it stranded me like my first one did in the pouring rain in Hope BC, 90 miles from home one fine day! Tow truck bill hurt a fair bit. Live and learn.

Dieselyoda if you want to read an excellent description of debugging this problem read Paul Glaves article on troubleshooting in the August edition of the Owner News. Starts on page 30 with a fuel line issue and then he describes a classic HES failure. How he got to the bottom of it quickly is some top notch advice.

The August issue is still online here in digital format for members too but will be gone once the new one is posted.

http://digital.turn-page.com/title/4865