Water Pump Keeps Failing (3 pumps in 3 months)

I am on my third water pump in three months. When my first pump failed,it was rapidly leaking coolant and my coolant was completely drained by the time I reached the shop. On the second pump (which lasted 2 months), I noticed a high pitched whining and a slow coolant leak (via the level in the reserve tank) before the pump completely failed as before. The third pump lasted only three weeks and I noticed the same symptoms as before (intermittent whining from engine and dropping coolant level) but brought the car in for repairs before a complete pump failure. The mechanics at Pep Boys (who have replaced all of the pumps) have said that their pump may not be compatible with my vehicle (2000 vw cabrio) and are ordering a pump from the VW dealership. I am skeptical, as it seems very unlikely that so many pumps in a row would be defective. Is this a common problem with VW models? Is there anything else connected to the pump that could be causing these failures? I have also been told that the belt on the pump may be too tight or the tensioner may be faulty. If so, why wouldn’t the mechanics have seen this? Is there a way to check this myself? I have very limited experience in repairs, so any advice would be much appreciated! Thanks!

I wonder if they have checked belt tension and alignment.

This is a common problem with aftermarket remanufactured pumps. That is what Pep Boys was first using, I guarantee it. With 2 failures in short order, their replacing it with a VW factory new. I’m pretty sure they checked belt tension and other causes on the second, hopefully free under warranty, job. I also hope they recognize that they need a new supplier of reman parts.

Thanks for commenting! The second job was free under warranty (parts and labor) and this third job will be free labor, but I have to pay for the VW factory pump. Is there a quick way to check the tension and alignment on my own when I get the car back this time?

At least demand the money back from the failed aftermarket pump. This will lessen the blow.

As for checking the tension, you’ll need a tension gauge to accurately test it. Run-of-thumb check is that you should only be able to press down on the belt in-between two pulleys at least a foot apart and deflect it 1/2". If you have a serpentine system with a spring-loaded tensioner, this rule doesn’t apply.

How many kilometers on original coolant pump?

The biggest problem is that you are using Pep Boys to repair your car. They’re even worse then the dealerships.I wouldn’t take my bicycle to Pep Boys.
The best thing to do is to go to as reputable parts store, like Napa, and buy the water pump yourself and then have a trusted shop put the pump in for you.
And whats all this chat about tensioners and belt alignment? The tension on the belt is automaticly adjusted by the tensioner pully. And, if the belt pulleys weren’t aligned properly you wouldn’t be able to keep the belt on the engine. either way, improper tension, or misalignment your belts wouldn’t last
Pep Boy type shops will nickle and dime you to death. A trusted shop will fix it right the first time (Unconditoinally) and recommend any further work that needs to be done. Never be afraid to ask to see the old part before they send it in for a core charge and evaluate it yourself for flaws.

Is the water pump on this vehicle driven by the timing belt or by a serpentine/accessory belt?

Since no one else has suggested it, if the water pump is driven by a serpentine or accessory belt, open the hood. Start the car and put it in Park. Get out and look at the drive belt and pulleys edge on. If one of the pulleys is bent and is wobbling, you’ll be able to see it. Depending on how the water pump is constructed, it’s maybe just barely possible that a bent pulley could cause the bearings in the water pump to fail.

BTW, has anyone taken one of the failed water pumps apart to see where they failed?