Author Topic: Coolant drain plug blocked by engine  (Read 7766 times)

Offline wrchunter

  • Curious
  • Posts: 5
Coolant drain plug blocked by engine
« on: August 29, 2016, 11:27:31 PM »
My very first run in with a miss-designed BMW motorcycle part...had them for decades...airheads, K bikes, oil heads...and I went to drain the coolant from my newly acquired 1993 K75 S and found I could not completely unscrew the drain plug because of interference with the engine.  No problem...just pop off the coolant hose...but it is disappointing.  Just wanted to rant! Or did I do something wrong????http://www.motobrick.com/Smileys/MB_Smiley/falldown.gif
  • Albuquerque, New Mexico
  • 1993 K75S

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: Coolant drain plug blocked by engine
« Reply #1 on: August 29, 2016, 11:53:36 PM »
Welcome, wrchunter!

How about posting a photo of this low point in your life so we can all live this drama along with you?
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Motorhobo

  • +25 years of K75
  • ^ Quintessential Motobricker
  • Posts: 1530
Re: Coolant drain plug blocked by engine
« Reply #2 on: August 30, 2016, 01:26:57 PM »
I've found that some screws can only be removed with the OEM allen key -- not enough clearance to get any kind of socket or extension in there. Did you try it with the allen wrench?
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: Coolant drain plug blocked by engine
« Reply #3 on: August 30, 2016, 01:49:56 PM »
+1 on the photo.  I have three K bikes and have never had a problem removing a drain plug on any of them, even using my Harbor Freight Allen wrenches.  Even after replacing the plug with a sender for the temperature gauge I've not had any trouble.

In two+ years of hanging around these forums for the k bike I've not heard of anyone else having your problem, either.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Chaos

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 3157
  • Mars needs women!
Re: Coolant drain plug blocked by engine
« Reply #4 on: August 30, 2016, 04:35:27 PM »
It has a drain plug?  I just pull the hose off the bottom.
  • sw ohio
1987 K75S    VIN 0231
Original owner, Original litter
200,000 miles (plus or minus) and 5 paint jobs
sold 6/23
2023 Ural 2WD sidecar (BMW's bastard step child)

Offline F14CRAZY

  • ^ Quintessential Motobricker
  • Posts: 1091
Re: Coolant drain plug blocked by engine
« Reply #5 on: August 30, 2016, 04:57:31 PM »
Either just pull off the bottom hose or be cool and have a temperature sensor instead of a drain plug
  • Grand Rapids, MI
  • '87 K75C
'87 K75C w/ Pichler V1 fairing. LED's, CATZ driving lights, Audiovox cruise, LT top case, tons of other mods by Drake...


Offline wrchunter

  • Curious
  • Posts: 5
Re: Coolant drain plug blocked by engine
« Reply #6 on: August 30, 2016, 05:25:48 PM »
See attached photo. The rust colored drain plug, when unscrewed with a allen wrench, and then after removing the wrench, trying to unscrew the plug entirely...it butts up against the rectangular portion of the engine.
  • Albuquerque, New Mexico
  • 1993 K75S

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 4475
Re: Coolant drain plug blocked by engine
« Reply #7 on: August 30, 2016, 05:30:39 PM »
Weird I have a 92 K75S and never had a problem screwing mine out. :dunno
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: Coolant drain plug blocked by engine
« Reply #8 on: August 30, 2016, 06:32:22 PM »
That's not the drain plug.  The coolant drain plug is on the cylinder head side of the water pump.  If you have a temperature gauge it will be the sending unit for the gauge.

I am pretty sure that what you are trying to remove is the plug over the oil pressure relief valve.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: Coolant drain plug blocked by engine
« Reply #9 on: August 30, 2016, 06:38:50 PM »
If you have two sending units on the cylinder head side of the pump assembly, the water pump unit will be the lower one.  The other is for the oil pressure idiot light.

A word of caution, if you do have a sending unit for a temperature gauge, be careful not to put too much torque on it.  The walls are thin, and it isn't hard to twist the head off the sender resulting in a costly replacement.  Tighten it just about a quarter turn beyond finger tight.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: Coolant drain plug blocked by engine
« Reply #10 on: August 30, 2016, 06:45:49 PM »
As far as removing the plug in the photo, it is easy when the pump has been removed from the engine.  Since the pressure relief valve controls the oil pressure in the engine, I wouldn't doubt that the BMW engineers in their Teutonic wisdom opted to make it difficult to tamper with.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: Coolant drain plug blocked by engine
« Reply #11 on: August 30, 2016, 06:55:06 PM »
Take a look, wrchunter. Conveniently located for gravity operation.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline wrchunter

  • Curious
  • Posts: 5
Re: Coolant drain plug blocked by engine
« Reply #12 on: August 30, 2016, 10:10:13 PM »
Duh!  Thanks for the info.  My faith in the BMW engineers is restored and my fearlessness in the garage will have to be tempered!
  • Albuquerque, New Mexico
  • 1993 K75S

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: Coolant drain plug blocked by engine
« Reply #13 on: August 31, 2016, 08:37:51 AM »
We were all newbies at one time. 
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Tags: