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Thread: T5 Water Pump in R5 5cyl.TDI (discussion thread)

  1. #1
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    T5 Water Pump in R5 5cyl.TDI (discussion thread)

    Every owner of the T5 5cyl. TDI should be very concerned if he/she has to top up the cooling system.

    Leaking water pump is very common fault in T5 R5 engines and it could be very expensive repair. Water pump alone is well over $200 and you will also need the coolant and at least one or two engine oil changes, since the coolant always leak onto the engine oil - courtesy of the VW engineers.

    The cooling system in R5 engine is closed system and no coolant is lost to evaporation, so even the smallest drop in the coolant level means that there is a leak somewhere. Also be aware of that the dealer can top up your coolant without telling you, when you bring the van for scheduled servicing to them. Once your van is out of the manufacturer warranty it is one very expensive job. So, check the coolant level before you take your van to the dealer for any work.

    Some of my thoughts on the pump that I dismantled.

    Poor quality axial seal or badly designed area of the engine block where the impeller spins (too much pressure on axial seal) is most likely the cause of the water pump failure.

    The water pump appears robust but it is not.
    The pump’s shaft is spinning in the double ball bearing. The lack of proper bearing seals is further exposed by 2 draining holes in the pump’s body that should drain away the coolant that pass the shaft’s axial seal but the holes are quickly clogged up buy rust and the coolant flows straight into the ball bearing. The bearing’s balls are held apart and in the place with the plastic race, rather than metal one that melts away since the coolant is not sufficient in lubricating and cooling the bearing. With the collapsed race the w. pump’s shaft wobbles and quickly destroys what is left of the axial seal sealing capability, and the coolant can flow even faster into the engine oil.
    (my T5 used 0.75L of coolant during 1 trip of 30km, there were no drips from the tiny rubber hose at the back of the engine)

    The early detection of the failed water pump is crucial since the pump is driven from the timing gear train. The longer the w. pump gear bounces on the other gears that are in contact with it, the greater is the chance to damage the surface of the other gears teeth that are much more difficult to replace than the w. pump gear. Also at the other end of the w. pump shaft the impeller that wobbles will ruin (grind) the opposite surface inside the engine block, which will reduce the cooling system efficiency.


    Complete pump; showing rust from the coolant that passes w. pump axial seal and get trapped in the area between 2 O-rings.



    Bearing with the shaft pressed out of the pump's body.



    Pump's bearing showing that the coolant leak through the pump washes out all the grease and wears out the bearing.



    Detail damage of the bearing surface.

    Last edited by Transporter; 28-04-2012 at 01:18 PM.

  2. #2
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    Hello Transporter,

    Nice write up and photos.

    Certainly alarming results.

    Regards,

    Scott

  3. #3
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    the extended warranty looks more enticing every day. Thanks for the info.

  4. #4
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    Thanks for the very detailed explanation.

    Maybe we should replace the waterpump each time the gates couplings and freewheeling pullys are done, is that approx 100,000km

    Brian

  5. #5
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    Great post, Transporter.

    Quote Originally Posted by Tornado T5 View Post
    the extended warranty looks more enticing every day.
    Yep, just bought it for mine (it will be 3 years old very soon). I'd strongly recommend it to anyone keeping their van past the initial 3 year factory warranty.

    I really can't see me keeping my T5 after the extended warranty runs out in a further 3 years time.

    It's off to the dealer for some (more) engine-related warranty work on friday (I'll post details once I find out what is wrong). This is 3 times I have had problems severe enough to stop me driving it in 50,000km of amost pure highway driving (plus numerous other smaller problems - electrical, hinges etc). From the stories I read on here and the Brickyard forum I'm definitely not alone.

    The only other vehicle I've had that was this unreliable was an old, cheap Alfa Romeo Berlina 2000, and I knew what I was getting into there (nice to drive when it was going well , unfortunately that happy state of affairs rarely lasted long enough to savour the experience ).
    2017 MY18 Golf R 7.5 Wolfsburg wagon (boring white) delivered 21 Sep 2017, 2008 Octavia vRS wagon 2.0 TFSI 6M (bright yellow), 2006 T5 Transporter van 2.5 TDI 6M (gone but not forgotten).

  6. #6
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    Quote Originally Posted by BrianJ View Post
    Thanks for the very detailed explanation.

    Maybe we should replace the waterpump each time the gates couplings and freewheeling pullys are done, is that approx 100,000km

    Brian
    To replace the pump as a preventative maintenance, one would have to replace it every 40,000km, since on some T5's pump failed before 50,000km. I would rather fit an electrical water pump and blanking the hole in the engine block.

    Lets just believe for while that VW did some changes and replacement pumps are much better quality. Talking about replacement pump I could get Italian pump, Chinese made pump and German Kobelschmidt brand pump from HSY imports.

    Interestingly enough my dealer needed 2 days to get the pump in and wanted to charge me deposit for the old one, when I question that I was told that they’re sending them to Germany for recycling

  7. #7
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    Quote Originally Posted by Transporter View Post
    Interestingly enough my dealer needed 2 days to get the pump in and wanted to charge me deposit for the old one, when I question that I was told that they’re sending them to Germany for recycling
    I have three different theories on why they want them back :

    1 They want to destroy all evidence that there are problems with R5 waterpumps so they can deny that there is a problem (the paranoid manufacturer/designer conspiracy theory)

    2 They are so thick they still haven't managed to figure out why so many fail (the crappy designer + poor investigator theory)

    3 As long as most fail out of warranty VW and their dealers make lots of profit from replacing them when they cark, so keeping them out of circulation makes it harder for anyone to come up with a method of reconditioning or copying and selling them (capitalistic profit theory)

    When I consider leaking OEM sliding windows for T5s and given how long it has taken them and they still can't produce a leak free window I'm currently leaning slightly towards theory # 2, although #3 is also compelling
    2017 MY18 Golf R 7.5 Wolfsburg wagon (boring white) delivered 21 Sep 2017, 2008 Octavia vRS wagon 2.0 TFSI 6M (bright yellow), 2006 T5 Transporter van 2.5 TDI 6M (gone but not forgotten).

  8. #8
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    Or 4)........what Transporter is getting is actually a remanufactered water pump that the dealer can only source if they pay a deposit which they'll get back when they send the supplier the original pump.

    Not an uncommon situation with power steering pumps and the like

  9. #9
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    The sales person at the spare parts said; "they are sending them to Germany for recycling".

    I bought the water pump from HSY Imports. I would have to be crazy to pay deposit on a new pump from the dealer and give them the old one back.

    I let my imagination to run wild here and speculate a bit.

    Knowing that VW is/was replacing the same water pump after the warranty for free for the R5 Touareg owners leads me to speculation that:
    VW Germany is supplying the replacement water pump for free for the owners of R5 Touaregs and possibly T5 vans as well and wants the old unit back so he can receive the new one and sell it.

    But hey, that's only immagination and anything is possible, maybe they're sending it to Germany for recycling. Who knows?

  10. #10
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    Quote Originally Posted by gregozedobe View Post
    3 As long as most fail out of warranty VW and their dealers make lots of profit from replacing them when they cark, so keeping them out of circulation makes it harder for anyone to come up with a method of reconditioning or copying and selling them (capitalistic profit theory)
    Grego, there are already at least 2 aftermarket pumps available the one is made in China, the secondone is made in Italy, and the one I bought is Kolbenschmidt made in Germany (probably the same as used by VW) it was almost 1/2 price of the one made in China.

    I will hang on to the original pump body just in case the pump in my van fails again, than I will do a conversion to electrical water pump and use the pump body as a plug.
    Last edited by Transporter; 07-04-2019 at 08:53 AM.

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