k1100lt major oil leak

[dc007]

This is my first post here so hello! I recently acquired a 1993 k1100lt that starts and runs sorta ok. This will probably be the first of a few questions I have as I attempt to get this bike running right over the next few weeks, but this issue in particular is one that I cannot find any info on.
The timing cover absolutely vomits oil once bike is up to temperature, im guessing about 5 tablespoons at least. I've replaced the crank seal where the leak seems to come from as well as the hall sensor cover gasket 3 times to no avail. I can see taking off the hall cover that there is a "nick" in the cover to allow oil to run down along with the wires that go to the oil pressure sensor on the oil pump, but this is what really confuses me. The timing cover does not have a sealing surface for this little track that the wires run on, so any oil that runs from that nick will just wind up on the floor which is precisely my issue. So to put it simply, the oil seems to come from the hall sensor area and just pour out onto the floor in a way that is sort of "engineered to happen".  I have the whole engine apart so if pictures are needed to clarify then they can be provided. Any and all help is greatly appreciated,
thanks in advance!

[Laitch]

Please supply photos of the "nick."

The wiring channel was not designed specifically to conduct oil spillage although oil resulting from faulty or failing assembly might use it as an exit. The shaft seal and cover gasket were designed to prevent oil leakage. Small nicks can be successfully filled with a smear of RTV gasket silicone before setting the cork gasket onto the cover mating surface after the silicone has set. Verify that the rubber gasket at the top entrance to the wiring channel is seated correctly.

Verify that oil is not leaking from the weep hole at the bottom of the engine case just beneath the coolant/oil pump as seen in the attached photo.

[dc007]

I got this picture online of the hall cover, I marked with a circle the nick that the oil is coming through and marked with arrows the direction its heading. I looked through the service manual and it doesnt seem as if theres a wire thats supposed to go through this, which was my first assumption. I'm going to head over the to the storage shed where I keep the bike later today or tomorrow so ill double check that weep hole.

[Laitch]

That isn't a nick, its a channel in the casting.

If you needed to replace the seal more than once, it is likely it wasn't installed correctly. If the seal you use is like the seal in the attached photograph, it is a Teflon seal. Teflon seals must have their shaft sealing lips expanded before installation so they will not be deformed by being shoved along the shaft while the seal is being installed. They are also installed dry onto cleaned surfaces.

Expansion of the interior lip is usually done by preforming them by expansion with a cylinder of sufficient diameter. Some pill bottles work well for this. After preforming, the seal is installed to the correct depth and the interior seal lips contract around the shaft to seal oil from leaking out around it. Did you install the seal using this method?

[dc007]

That is the exact seal I installed to originally try and solve this issue, and I now know I did not do it properly as I just pulled the old one out and slid this one in. So to clarify, now that I have the whole engine apart I should: install the new seal that ive ordered into the timing cover, then expand it using something slightly larger than the part it seals to, and lastly put the whole timing cover back on? For the seal I have a couple questions: Is this seal the kind of seal that needs to be replaced any time the part it seals to is removed and reinstalled? and do I have to leave the bike alone for a good while to allow time for the teflon to contract? Thanks very much for your help!

[Laitch]

I haven't dealt with a K1100 timing case seal. I can tell you I've removed and re-installed the timing case cover of my K75 without creating a seal leak.

Are you using the BMW K1100 workshop manual during your work?

[dc007]

Yes, I've been using the bmw shop manual which unfortunately barely describes how to replace this part. I have a haynes manual somewhere im gonna have to find and see if that gives any more helpful detail.

[Laitch]

I have a haynes manual somewhere im gonna have to find and see if that gives any more helpful detail.

My Haynes manual is only useful for 2-valve engines; your engine is a 4-valve. I haven't seen a Haynes 4V manual.

If I had a 4-valve I'd be following the attached instruction from BMW's K1100 manual because I have no imagination. Regardless of which direction I decided to install it, I'd be using a wrench socket of suitable diameter if appropriate. I wouldn't be buying BMW's special tool. Maybe somebody with a K1100 will chime in here.

[Scott_]

I can say I've only had the timing cover of my '95 off 1x to replace the chain tension guide(worn from mileage). I don't recall having to replace the seal just because I removed the cover.
Was able to reassemble with no issues and no leaks.

[dc007]

I've looked at it a good bit more these past two days after my new seal arrived in the mail, and I think I might have had a bit of a revelation. There's a hole that goes through the hall sensors "gate rotor", which is the part that the teflon seals against, and ive discovered that the end of the crank behind this rotor is threaded for a m10x1.0 bolt. This bike leaked from this area when I got it and it definitely did not have a bolt holding that rotor in. Basically I believe I'm missing a bolt that would hold the rotor and timing chain sprocket snugly to the crank so the teflon can actually seal, however absolutely nowhere online can I find this bolt being sold. I have confirmed it to be a m10x1.0 thread size however.

[Laitch]

There are two steps you should take immediately before you proceed any further:

• Go to the Service Manual section of the Technical Directory here and download the BMW K1100 workshop manual.
• Get acquainted with Max BMW parts fiche's K1100LT section (Section 11, diagram 1821) to view an exploded diagram of the assembly. These diagrams are not always perfectly accurate because BMW makes sometimes makes revisions in engineering in its models during production, but these diagrams can clear away the fog and get you close or all the way home when used with the manual. They are much easier learning to use than rebuilding your Brick by using your imagination.

Max also has prompt service with parts in stock and will let you know when the parts will need to come from overseas. Max is who I deal with because I'm in New England and like the style of the fiche they are using. I've purchased from Bob's in Maryland with good results, too, but Max always includes M&Ms with the order, so there you go. realoem is used by many here but doesn't have prices listed because it isn't a vendor. I took a guess at your Brick's month of production at realoem. Put the last seven digits from your serial number in the serial number box to get the most accurate date of production. Some parts differ from the 1993 in '94.

Here's a diagram from the K1100 manual at Motobrick.

[Ingo]

So, when I had mine apart I forgot to tighten down that bolt. Bike ran fine. Then started leaking. Then finally misfired and then quit. Had to tighten it up on side of road... No issue since.

[Laitch]

Then finally misfired and then quit. Had to tighten it up on side of road... No issue since.

It seems like the timing didn't move on you. It looks like a pin links the rotor flange and the timing chain drive sprocket. Did the two of those start walking up the bolt threads?

[dc007]

I found the mystery bolt in my box of miscellaneous parts, so when I get my engine all cleaned up and put back together I have high hopes for it sealing up nice this time around. And similarly to Ingo I ran this bike for quite a bit without the timing moving out of where it should be because the timing cover doesn't seem to give enough clearance for the hall rotor's pin to slide fully out of the crank, so it keeps the timing gear where it should be.

[Laitch]