Question on Coolants in TDI

bugowner

Active member
Joined
Jun 19, 2004
Location
Canada, British Columbia
TDI
1999 Beetle TDI
Hi
I am doing some Mechanical Work on my 1999 New Beetle. I want to do a Flush with some of that Prestone Radiator Flush and Cleaner and I want to drain all the current Antifreeze from the system first. I read somewhere that the Pentosin G12, used in my car, has some sort of Lubricant in it and hence my question.
If I just used Distilled water and this cleaner and ran the car for a few days with only this in it, to let it get around the system so to speak, would I damage the Water Pump in any way? (Given that there might not be any lubricant for the Water Pump) if that information is even correct?
Concerned and would like some help...
Robert
 

AndyBees

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Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Wow!

Are you having cooling issues with the engine?
 

turbobrick240

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Nov 18, 2014
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maine
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2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
I'd just flush it out with plain water unless the coolant looks real nasty/rusty/sedimenty.
 

Vince Waldon

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Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
The waterpump has bearings lubricated from the factory... so no worries there.

That said, the enemy of cooling systems is rust, so I'd not want to run pure distilled water for very long.

Plus, winter is coming... if there's a cold snap while you're running around town with pure distilled water boom goes the block.

A quick flush with distilled water (t-stat removed so that it circulates everywhere) might be ok, but I'd get real coolant in there as soon as possible.

If you're concerned and/or still see evidence of contamination, change the coolant again... it's not that expensive. Or, change it early... a year from now, say. Technically it's good for the life of the car... or certainly the life of the timing belt. :)
 

bugowner

Active member
Joined
Jun 19, 2004
Location
Canada, British Columbia
TDI
1999 Beetle TDI
The waterpump has bearings lubricated from the factory... so no worries there.

That said, the enemy of cooling systems is rust, so I'd not want to run pure distilled water for very long.

Plus, winter is coming... if there's a cold snap while you're running around town with pure distilled water boom goes the block.

A quick flush with distilled water (t-stat removed so that it circulates everywhere) might be ok, but I'd get real coolant in there as soon as possible.

If you're concerned and/or still see evidence of contamination, change the coolant again... it's not that expensive. Or, change it early... a year from now, say. Technically it's good for the life of the car... or certainly the life of the timing belt. :)
Hi Vince
Thank you for your reply. OK So I guess that Coolant having a Lubricant in it is at best an exaggeration. I thought that the Water Pump was Sealed and lifetime lubricated, by design.
I was intending to proceed to the Final Fill tomorrow and we are having some great fall weather on the Coast so it does need to get done soon. Do you have any suggestions on getting the new mix into the system. Fill the radiator separately? Disconnect a hose near the top of the engine and let the new mix gravity feed (from the storage reservoir) to that point and then connect hose. (All of this without having the engine running, of course). Any tips would be much appreciated.
Thanks again for your help...
Robert
 

turbobrick240

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Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
OK I just happened to have extra Distilled Water but I understand what you are saying. Thanks...
Robert
Perfect. I meant either tap or distilled water w/o the acid flush. After a thorough water flush or two I'd add three liters of straight g12. Then top the rest of the way up w a 25/75 g12/water mix. That will give at least a 50/50 ratio in the 6 liter coolant capacity(assuming you get all 3 liters of g12 in). Like Vince said, don't leave straight water in there very long.
 

bugowner

Active member
Joined
Jun 19, 2004
Location
Canada, British Columbia
TDI
1999 Beetle TDI
Perfect. I meant either tap or distilled water w/o the acid flush. After a thorough water flush or two I'd add three liters of straight g12. Then top the rest of the way up w a 25/75 g12/water mix. That will give at least a 50/50 ratio in the 6 liter coolant capacity(assuming you get all 3 liters of g12 in). Like Vince said, don't leave straight water in there very long.
Understood. Thanks again...
Robert
 

Vince Waldon

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Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
Do you have any suggestions on getting the new mix into the system. Fill the radiator separately?
From a schematic perspective the cooling system has all kinds of twists and turns, and the t-stat completely isolates one end of the radiator loop, but the good news is that all of it is downhill of the reservoir bottle, so it will fill well if you just add coolant slowly to the bottle.

When I do it I then run the engine up to operating temperature (may need someone to step on the throttle a bit as these engines produce so little waste heat at idle)... adding coolant as required. Eventually the t-stat will open, coolant will circulate thru all the nooks and crannies, and air bubbles will purge themselves.

Let the engine cool overnight and then do a final top-up, if required... bob's yer uncle. :)

we are having some great fall weather on the Coast
Same here in Edmonton.. those first couple snowfalls were very annoying but we're back into the 20s for the next week or two...ah... yardwork. :)
 
Last edited:

Vince Waldon

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Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
Actually, there are no freeze plugs on an ALH block (and most if not all VW diesel blocks that followed).

Hence "coolant heaters" as opposed to "block heaters". :)
 

Mongler98

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Mar 23, 2011
Location
COLORADO (SE of Denver)
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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
drain system, fill with distilled water and about a cup of laundry detergent, drive till nice and warm, drain, 2 more flushes of just distilled water and driven till war, drain and add in MIXED 50/50 or mix it yourself and burp, thats all. here is a helpfull video.
https://www.youtube.com/watch?v=s--5ft5YiHg
 

bugowner

Active member
Joined
Jun 19, 2004
Location
Canada, British Columbia
TDI
1999 Beetle TDI
From a schematic perspective the cooling system has all kinds of twists and turns, and the t-stat completely isolates one end of the radiator loop, but the good news is that all of it is downhill of the reservoir bottle, so it will fill well if you just add coolant slowly to the bottle.

When I do it I then run the engine up to operating temperature (may need someone to step on the throttle a bit as these engines produce so little waste heat at idle)... adding coolant as required. Eventually the t-stat will open, coolant will circulate thru all the nooks and crannies, and air bubbles will purge themselves.

Let the engine cool overnight and then do a final top-up, if required... bob's yer uncle. :)

Same here in Edmonton.. those first couple snowfalls were very annoying but we're back into the 20s for the next week or two...ah... yardwork. :)

Hi Vince
Well, the deed is done and it worked perfectly. It tests -37C and runs like a baby. The cooling system on the TDI is not similar to ones I have lookedd at before but I see why they do many of the things they do.
I really appreciate the great help you personally answering my questions has been. I wonder sometimes if my questions are silly but details are so important in these complex machines.
Glad to hear that you are having some great weather as well. Cheers...
Robert
 

bugowner

Active member
Joined
Jun 19, 2004
Location
Canada, British Columbia
TDI
1999 Beetle TDI
drain system, fill with distilled water and about a cup of laundry detergent, drive till nice and warm, drain, 2 more flushes of just distilled water and driven till war, drain and add in MIXED 50/50 or mix it yourself and burp, thats all. here is a helpfull video.
https://www.youtube.com/watch?v=s--5ft5YiHg
Hi Mongler98
Thank you. That video was very helpful. I actually have some his other videos and he does a very good job producing them. Cheers...
Robert
 
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