Auxilliary coolant pump for turbo - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• Auxilliary coolant pump for turbo by vwjones on 23 Aug, 2009 18:06
• I have a GTD with a T2 that has an aux. coolant pump.  the thermal switch is dead and I was thinking of wiring it up to come on after shutdown via a timer since I have no idea where to get a thermal switch that will fit.  Does anyone know if the main water pump feeds the turbo's water jacket when the engine is running?  I'm thinking that I propbably only need the aux after the ignition is switched off to prevent the coolant from boiling in the turbo.
• #1 by vwjones on 23 Aug, 2009 19:43
• Quote from: libbybapa on 23 Aug, 2009 19:16

  The reason for the after-run pump is to keep the coolant from boiling in the turbo after engine shutdown.  Running the pump from a timer is really not ideal as the time necessary for cycling the coolant is extremely variable even if you always cool your car down after driving.  It can literally vary from not running at all to running for longer than 5 minutes.  I would recommend either getting the correct sender (I believe they were also fitted to some of the gasser motors and so are likely available) or fitting one of these:
  
  http://www.summitracing.com/parts/DER-16749/
  
  It works very well and is simple to dial in to the temperature that keeps the coolant from boiling.
  
  Andrew
  
  just what i was looking for.  thanks
  
• #2 by BK75 on 28 Aug, 2009 07:09
• I haven't tried but my guess is that the Summit kit quoted above has the wrong threads to fit the same hole on a metric car.   Has anyone actually used this setup in this application? 
  
  Does anyone know what the part number for the OE coolant sensor might be?   I am in the same prediciment but would like to simply replace the broken part rather than try to improve or replace it with some thing else.
• #3 by vwjones on 28 Aug, 2009 10:18
• Quote from: libbybapa on 28 Aug, 2009 07:28

  I have used the above kit, but not for this specific application.  The threads on the Derale sensor are NPT and so I would be very surprised if they fit any stock VW threads.
  
  Andrew
  

  
  i had a 180ish thermal switch in my box of tricks so since I had the truck wired for the original vw switch anyway, I simply wired up the thermal switch and bolted it to the firewall, isolated from the firewall itself behind near  trubo.  It comes on while the truck is running and usually runs 2 or 3 minutes after shutdown.  It probably doesn't work exactly to vw specs but it will keep the turbo from boiling.  You can but them at most auto parts stores
• #4 by BK75 on 03 Sep, 2009 18:52
• Ok so I found the number.    p/n 357919521
  
  Anyone know where to find one?   Or how to get one domestically?
• #5 by wil892 on 04 Sep, 2009 02:55
• There is an SB engine in a scrap yard near me but it has been there for so long im not sure the sensor would still work. Its in a passat so it has the water cooled turbo. IF you need it I could go take it off. I have no idea how to test it though as I dont have a multimeter.
  
  Will