K11 Owners Group

Wrigsby1 · Posted: Tue Aug 25, 2009 4:53 pm Post subject: K1100 Head gasket

Hi again

My recently aquired K11LT is getting its jobs to do list sorted and I amay have come across an odd one.

Has anyone had a head gasket failure? I picked the bike up and rode 500 miles in the next couple of days to get home. I parked on the ferry and the header tank overflowed. I put this down to fan, or switch, thermostat or pressure cap.

Receipts show "switch" replaced and I also have some spares from a K11LT that I broke up. I went to change the pressure cap and found it was slightly "creamy" and had a very odd trick done to a rubber seal. The seal had 1/4 cut away, ho hum. The cap is different in that it doesn't seal the same way but the neck on this bike is the same as my old one! I have changed the cap anyway and the part number ends in 20.

Has someone cut this seal to stop the water system pressuring properly and therefore causing the overflow? The overflow did seem a bit premature but hasn't happemned again on the shorter runs.

There is no sulfated oil on the underside of the oil filler cap but i will get the bike nice and hot over the next couple of days to see if this happens.

The fans on the earlier ones seem to cut in a bit late as i remember. Do i remember correctly?

The front cylinder/underside of the head is a little oily. I am suspicious and don't like messing about chasing my tail for problems!!

Still a great bike and i haven't heard of may K gasket probs.

Ta
G

Flying Duck · Posted: Tue Aug 25, 2009 5:08 pm Post subject:

HG failures do happen but they're pretty rare.

What's a "header tank" - the coolant reservoir under the seat?

Not sure why anyone would mess with the radiator cap seal. I suspect that's why it overflowed.

A little oily under the front cylinder is most likely just road grime.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

Scott_Anderson · Posted: Tue Aug 25, 2009 5:41 pm Post subject:

Ask Rydor his opinion of head gasket failures and the associated radiator cap seal as we had to improv a new one during our day trip at HM 1 last year.
_________________
Ride safe.

1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

Wrigsby1 · Posted: Tue Aug 25, 2009 6:37 pm Post subject:

Yep, the header tank mentioned is the resevoir under the seat. This is where the overflow occurred if that gives and clue. The cap off my old bike was noticably different on the sealing lip. There is always a chance that the one removed was off an older bike. I am just a little suss as to why someone would mess about with the seal.

As per usual, a merciless ride will sort out if its a problem or not!

Thanks for the advice so far.

G

Tim (Midland Section) · Posted: Tue Aug 25, 2009 7:50 pm Post subject:

Morning Wrigsby, My K11 has an oil mist coming along the head. I think it's from the timing chain cover, only been like that for 2 years.
Re the water, mine has only done that once, after a very slow 1 in 3, 3000 foot hill climb in 30C heat. The hotel was at the top & it blew off coz I stopped the engine as soon as I arrived, no water circulation!
Get it hot, Top it up at the radiator, run it at tickover, if the gasket has gone, it will blow bubbles, stop engine, squeeze the pipes to expel any air, top up again if necessary, fit the cap. Run it around a bit, check header tank. Better on the low side. keep an eye on it, call back if more advice needed.
_________________
Regards Tim,

Grey haired riders don't get that way by pure luck
1996 Guzzi Cali3 LAPD
1972 750 Commando
G6HRN
#485

Mystic Red · Posted: Tue Aug 25, 2009 8:53 pm Post subject:

Also, if you fill the "header tank" to max level it will blow off water until it's happy with the level! Very Happy

_________________
Scott Hespelt, '94 K11LT
K11 OG #466

Phil Marvin · Posted: Tue Aug 25, 2009 9:58 pm Post subject:

Hi, Wrigsby,
My first K1100LT (1996) used to overflow the tank. I kept the tank up to the "full" mark. After a couple of times, the coolant was close to the "add" mark. It would still overflow just a bit. I replaced the cap with a new one, making sure both gaskets were there, and had no further problem. I also quit filling the tank to the "full" mark, filling it to just a bit past the "add" mark. I filled my second K1100LT (1995) the same way and currently do the same to my K75 bikes. I haven't had an overflow problem in years.
_________________
Ride Safe,
Phil Marvin in El Paso, TX
'94 K75A/3
'95 K75RTP

Wrigsby1 · Posted: Wed Aug 26, 2009 1:47 pm Post subject:

Thanks for the great replies! I monitored the tank today after a 10 mile ride and i have probably over filled it as its at max and it was at the top after running for a couple of minutes at standstill.

I am also going ot check the curcuit for the fan and keep an eye on it all.

I had a K100LT and a K1100LT 96 and had no problems with overflow. The K100 used to get so hot in summer that your legs could scorch! the K11 seemed to have a nicely active fan that kept thing slightly cooler. I seem to remember that BMW fitted a lower temp "switching" switch to the later K11's. On my last K11 I had problems getting it hot enough on winter runs to the point where the oil emulsified and clogged the starter sprag clutch.

The oil mist is further towards the head gasket than the cam cover gasket. The K100 had no real oily bits but the K11 had a few. I guess that this one is still getting the over active mind syndrome as well.

This is a good forum and thanks again for hte help. I better go find a big hill and a hot day a la Tim which is a good excuse for a holiday!

Cheers
G

Technician · Posted: Wed Aug 26, 2009 2:37 pm Post subject:

If you're really worried about the head gasket then if you have a friendly mechanic/garage locally ask them to carry out a "sniff" test. This uses a special tool which is basically a tube with rubber fittings and filter that locates in the filler neck and contains a special fluid. The engine is run up to operating temperature and the tool sucks the gases through the fluid, if you have a combustion leak [head gasket] the fluid will change colour. I have this tool but am at the opposite end of the country otherwise i'd help out.
_________________
Fat Ba***d with a K1100LTse
Squire D18 trailer
Garmin Zumo 660
"Run it round the block to see if the wheels fall off!!!!"

Flying Duck · Posted: Wed Aug 26, 2009 3:09 pm Post subject:

That reminds me: There's also another method where they put some flourescent die in the oil, then you drive/ride for a while and then with a UV light they can determine if/where oil is coming out.

The shop did that on my dad's minivan to determine if a leak was coming from the head or the main seal. The dealer wanted to fix both "just in case" Rolling Eyes

so I took it to an indy shop that thought diagnosing it properly first would be a little more cost effective.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

Wrigsby1 · Posted: Wed Aug 26, 2009 6:56 pm Post subject:

Thanks again chaps. I checked the fan tonight - working, I drained the coolent from the resevoir to half way between full and empty. I think things are probably OK but I am still mystified by the pressure cap that I removed. On RealOEM parts checker I can find no mention about the BMW cap I removed on any of the watercooled BM's. My spare was the correct part and they differ slightly in how the seal on the neck to create the pressure seal. Beats me!

As for the seal with the 1/4 cut out, it was one of two seals present, one whole one cut. W-i-e-r-d...

Years ago when i was a courier, the mantra was, "ride harder and if it's suss it will break". "It" rarely did!

Ta
G

Cheers
Guy

Mystic Red · Posted: Wed Aug 26, 2009 9:56 pm Post subject:

Jim · Posted: Wed Aug 26, 2009 11:31 pm Post subject:

chiefly British, informal (also Canadian)

* Pronunciation: \ˈsəs\
* Function: transitive verb
* Etymology: by shortening & alteration from suspect

1 chiefly British : figure out —usually used with out
2 chiefly British : to inspect or investigate so as to gain more knowledge —usually used with out

realize; grasp: he's sussed it [with clause] he sussed out right away there was something fishy going on.

Origin 1930's: abbreviation of suspect, suspicion.
_________________
Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

Milton · Posted: Sun Aug 30, 2009 3:40 pm Post subject:

Be careful with the gasket under the radiator cap. I had a slight kink in mine and it gave me fits for several weeks before I figured out what the problem was. It would cool fine under normal riding but if I rode hard or under heavy load it would overflow the reservoir under the seat; just enough pressure to blow by the kink. I took the gasket out, put it in a pan of hot water and then pressed it between 2 sheets of aluminum with weight on top. Replaced the gasket and made sure it was well seated before sealing the radiator back up. No problems since.

Milton S.
_________________
Jethro Tull: Thick as a Brick!

1992 K100RS 48K. Dead for now.
1998 Triumph Tiger 43K->56K. Doin it in the dirt.
1978 Honda CB400T 32.5K. For my boys.

Wrigsby1 · Posted: Fri Sep 04, 2009 9:30 am Post subject:

Thanks for the last reply. I checked my repalcement cap (the correct one!) and the gasket was OK and the cap is keeping clean. The bike had a good test last week when I was marshalling a small cycle event with some mates and the bike ran nice and hot with no probs.

I thought the HGF may be a bit unexpected but when you spot odd tricks like the gasket on the old coolent cap, you get a bit edgy.

Cheers
G