Author Topic: MK2 1.6 NA Diesel Coolant Replacement  (Read 3984 times)

June 18, 2017, 04:47:02 pm

thomas m

  • Junior

  • Offline
  • **

  • 144
MK2 1.6 NA Diesel Coolant Replacement
« on: June 18, 2017, 04:47:02 pm »
I'd like to do a quick drain and refill of my coolant without removing the v-belts and power steering pump. My thermostat was replaced a short time ago.

It says to release the 2 hoses shown in the figure at  #1
Will the heater core (in the cabin) drain if the Bentley procedures are followed?
Will the block drain completely as they say??



Also, they say to refill via the overflow bottle. Will that work and fill the engine completely??

« Last Edit: June 18, 2017, 04:48:37 pm by thomas m »


Thomas, Original owner since new:
1991 MK2 Jetta Non-turbo 1.6 diesel, Engine Code ME, 5 speed 020 AWY 04120 transmission, Hydraulic Lifters,
320,000 miles
Location: Vancouver, WA
LOOKING FOR REBUILD OPTIONS IN PORTLAND, OR OR ON THE WEST COAST

Reply #1June 19, 2017, 12:42:42 pm

vanbcguy

  • Administrator
  • Veteran

  • Offline
  • *****

  • 2831
  • Personal Text
    Vancouver, BC
Re: MK2 1.6 NA Diesel Coolant Replacement
« Reply #1 on: June 19, 2017, 12:42:42 pm »
If you pop both of those hoses off you can get most of the coolant out. Be sure to remove the cap from the expansion tank!

Yes, you can fill entirely from the expansion tank. It is the high point in the system. You'll want to fill it up then fire the engine with the cap off. You'll need to continue topping it up as air is purged from the system. The small hose to the top of the expansion tank is responsible for purging air from the system, you should have a good stream of coolant coming through it. You'll see the air bubbles come out that way too.

Sent from my LG-H873 using Tapatalk

Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #2June 27, 2017, 06:39:44 pm

thomas m

  • Junior

  • Offline
  • **

  • 144
Re: MK2 1.6 NA Diesel Coolant Replacement
« Reply #2 on: June 27, 2017, 06:39:44 pm »
I decided to pull and replace the thermostat. Issue with that in a separate posting.

With that out, I coaxed a little more fluid out by jacking up each side.

I also back-flushed the heater core and radiator.

I filled the block through the cylinder head, then filled through the bottle as it took fluid.

Thanks for the tips.
Thomas, Original owner since new:
1991 MK2 Jetta Non-turbo 1.6 diesel, Engine Code ME, 5 speed 020 AWY 04120 transmission, Hydraulic Lifters,
320,000 miles
Location: Vancouver, WA
LOOKING FOR REBUILD OPTIONS IN PORTLAND, OR OR ON THE WEST COAST

Reply #3July 05, 2017, 12:17:28 pm

air-cooled or diesel

  • Guest
Re: MK2 1.6 NA Diesel Coolant Replacement
« Reply #3 on: July 05, 2017, 12:17:28 pm »
i find heater core is high in system and wont drain, i take hose off return hard line, and blow some air thru it, use mouth, compressor could blow core, and you find water/coolant will push out of core. a little better of a result.
^:that is with drain already open.
« Last Edit: July 05, 2017, 12:26:15 pm by air-cooled or diesel »

Reply #4July 05, 2017, 08:15:20 pm

thomas m

  • Junior

  • Offline
  • **

  • 144
Re: MK2 1.6 NA Diesel Coolant Replacement
« Reply #4 on: July 05, 2017, 08:15:20 pm »
i find heater core is high in system and wont drain, i take hose off return hard line, and blow some air thru it, use mouth, compressor could blow core, and you find water/coolant will push out of core. a little better of a result.
^:that is with drain already open.

Thanks, Aircooled !!
I did that and while at it I backed flushed the heater core (and radiator) with water being careful not to pressurize them, just move any crud out.
I used my shopvac hose attached to the radiator out hose to siphon water back through the radiator. The heater core was easier.
Thomas, Original owner since new:
1991 MK2 Jetta Non-turbo 1.6 diesel, Engine Code ME, 5 speed 020 AWY 04120 transmission, Hydraulic Lifters,
320,000 miles
Location: Vancouver, WA
LOOKING FOR REBUILD OPTIONS IN PORTLAND, OR OR ON THE WEST COAST