Water Pump Failure

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Yes, I've read that post by Frank.

I've done a lot of ALH TB jobs and only a couple of PDs. I don't think I've seen a water pump that didn't have a little crusty dried pink stuff along the lower edge and in most cases they were wet and leaking.

My Water Pump failed at roughly 50k miles and it was not leaking prior to the incident. It was on the ALH in my Vanagon which I use as a daily driver. I was not having to add coolant. So, in my opinion, just because a WP is weeping/leaking doesn't mean it is going to lock-up.

Also, 4th gear in my Vanagon is geared about the same as 4th gear in the Jetta/Golf/NB. So, when I'm cruising 70 mph the engine is spinning about 3050 RPMs, not the typical 2375 at that speed. However, I doubt that had anything to do with the failure.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
I'm intrigued by the failures. It seems like a higher than acceptable level of failure and the only thing I could think of aside from MFG defect could be over tightening of the belt? I'm all ears...but if it were overtightened, shouldn't there be play in the shaft bearings. Could if be wrong coolant? I've seen green coolant in ALH cars...how much does it hurt things?

Or is it just bad water pumps?

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No green coolant in either -- in the case of my vehicle (now my daughter's) I remain the only person who has turned a wrench on it since it was new in 2003.

In both cases the tensioner indicator was set correctly when I saw it; in my case I know it always was (since I did the belt the previous time) and in the case of my friend's car it was in the notch -- but I was not the person who did the belt the previous time around. However, given that it was correctly set when it failed and everything else in the timing belt chain looked fine I highly doubt it was overtensioned.....

In both failures I saw it leaked badly enough to require make-up coolant be added. In my car's case it was dropping a very small amount on the floor on occasion (drops, not puddles) but I suspect the real loss was happening while the engine was running. I doubt the bearing will do well with coolant in it, so once that seal goes I would expect bearing failure to follow in pretty short order.
 
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AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
I've personally seen three kinds of catastrophic Water Pump failures.

1. Impeller slipping on the shaft resulting in overheating bad enough to blow the head gasket (gasser engine, and young college age girl behind the wheel).

2. Shaft/bearing shot to the point the shaft was "loose" in the bearing/housing which resulted in loss off coolant but no over-heat due to observant driver.

3. Water Pump locked-up with zero warning on my engine....... no warning, meaning had not heard anything nor had I been having to add coolant.

I don't over-tension belts.
 

jokila

Vendor
Joined
Dec 3, 2004
Location
Houston, Texas
TDI
2003 Jetta GLS, Manual
I'm intrigued by the failures. It seems like a higher than acceptable level of failure and the only thing I could think of aside from MFG defect could be over tightening of the belt? I'm all ears...but if it were overtightened, shouldn't there be play in the shaft bearings. Could if be wrong coolant? I've seen green coolant in ALH cars...how much does it hurt things?

Or is it just bad water pumps?

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It's not going to be over tightening the tensioner/belt on mine either.
 

WildChild80

Veteran Member
Joined
May 30, 2016
Location
Nashville, AR
TDI
2001 Jetta TDI 2000 Jetta TDI 2000 New Beetle TDI ALL 5 speeds
When I bought my first TDI it was a water pump failure, specifically bearing failure but not ceased but way out of alignment.

Maybe this is just random MFG defects or a very large forum

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AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
If it is any consolation to anyone, I've seen a good number of WPs go way beyond the 100k mile change interval without any problems. I'm sure others have seen the same.

102k miles (the one in my 03 right now)
106k on a 60k mile belt that broke, WP was okay
108k miles on the OE, 04 Jetta BEW
119k miles on the OE, 03 Jetta SW
138k miles on the OE, and 142k miles on a kit from Idparts (same car)
149k miles on an 01 Jetta
152k miles on an 01 Jetta
167k miles on the OE WP on my previously owned 2000 Jetta (TB and Tensioner were changed at 100k.

Those are the ones I remember. I cannot recall changing the TB on any vehicle before the recommended change interval....
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
There's very little tension to be overdone in the tensioner. You can continue to turn the inner part of the tensioner but soon after you pass the mark it flips over completely. Another side load could be imparted by a belt that isn't running perfectly true. Mine was running more towards the inner edge of the cam and ip sprockets so I will try and adjust the big accessory bracket, probably loosen and rotate counter clockwise as viewed from the front bumper.
 

jackfolstam

Veteran Member
Joined
Oct 14, 2016
Location
CA
TDI
MkI Rabbit ALH swap
So it's been a year on the new water pump and repair. I didn't mention it before but I returned the Graf wp and got a refurbed VW one during the holiday sales. New thoughts are, what could the reman process be for these pumps? At most it could be that a bushing is replaced as well as the rotating assembly. In that case there's not many reasons why a reman will not go the 100k miles. The oem pump has a spocket with holes in it (instead of solid) and the impeller is black 'composite.'

Also, what are the advantages of having an internal water pump? Compact design? Less seals to leak? 1 more single point of failure that could destroy an entire engine?
 

WildChild80

Veteran Member
Joined
May 30, 2016
Location
Nashville, AR
TDI
2001 Jetta TDI 2000 Jetta TDI 2000 New Beetle TDI ALL 5 speeds
Well heat will kill a diesel and in an interference engine, if the timing belt breaks you loose cooling but that's a moot point since the engine stopped when the belt broke. I believe the reason is for survivability, it may drain the battery in you loose a serpentine belt but it won't overheat

Now, had you read up on what water pump to get, you'd have sent the "composite" spoken plastic impeller back and went with a metal one, the plastic ones occasionally spin on the shaft and present similar to a blown head gasket and could also cause a head gasket to let go if you cook the engine.

Good luck, hope things go better than the last one

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wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Just my personal opinion, you couldn't pay me enough to install a rebuilt water pump.
I use to buy them in the 70's. After installing 3 in my Ford the 4th was new.
Takes me time to see the pattern. :)

Did sell the car shortly after when I got my 1st VW Type 3 wagon.
Didn't hold as much but got better fuel mileage.
 
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