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So my waterpump is leaking. Again. My minimal diagnosis is there is a constant drip coming from behind the water pump pulley (or the front of the block - but I'm sure its the pulley). No power loss, no weird noises, no death. The coolant was bubbling a tad last night after a spirited drive, which leads me to think it has lost pressure in the system. Coolant/distilled water mix that has fallen out isn't oily.

This is the 3rd bloody pump that I have had fail (well I am pretty sure its the pump - has all the signs from the last 2 times) on me in the past 12 months.

What on earth am I doing wrong? The pump in there now was bought from Auto+ - so I'm pretty sure its not a cheap ebay one like the 2nd one that failed. I used genuine gaskets all through when I replaced it last time. The alt/pump drive belt has had a bit of a squeal in the past 2 months from being a tad loose - so its not a tightening issue.

I am ready to set this thing on fire to be honest. Anybody want to sell me a b6?

Pumps on ebay range in quality from better than OEM down to plain horrible. Pumps from places like Auto+ and Supercheap tend more towards the horrible end of the scale. They're from the same sorts of cheap factories that crap ebay sellers source from.

Try a Japanese made GMB branded pump from ebay. Make sure you do the due diligence on the seller and the fact that it really is GMB. Otherwise get a Japanese made OEM Mazda one from Amayama. Last resort get one from Mazda Australia (but check first that Mazda still carry genuine jap ones).

Thanks mate. I've got Wednesday off so I'll rip it all apart and get a closer look. Amayama may be the way to go.

Something that intrigues me is - I went and get the car to idle for 5 minutes just to see what happens. The drip stopped as soon as the engine was on.....but started up again the second I turned it off. The overflow was bubbling away when it switched off too. Didn't quite reach its normal temp.

It'd be a good idea to have a bit of a check to make sure it's not something in the motor that's making the pumps fail. Have a look and make sure all the pulleys run straight and true and the belt runs smoothly. Also check belt tension aganst spec: Mazda's spec is 8-9mm (new belt) or 9-10mm (old belt) deflection between the alternator and the crankshaft under a 10Kg load.

Yeah thoroughly clean the suspect area and check before pulling things apart.
Another vote for the GMB PowerMax pumps. The casting for those are much cleaner than OEM. Had a quick look on eBay and the green box ones are $50. They seem to have new black/white packaging too but I would go with the old ones.

manga_blue wrote:Pumps from places like Auto+ and Supercheap tend more towards the horrible end of the scale.

Auto+ don't sell water pumps toward the horrible end of the scale. I don't believe GMB pumps are to be low quality.... Áuto+ has sold and installed hundreds over the last 8 years. If they were problematic Auto+ would have changed manufacturer/supplier than risk warranty claims and re-work!

Apologies, Danny. Auto+ are not who I thought they are. I have a parts chain here with a very similar name that I prefer to buy oils and cleaners, etc from but definitely nothing else. The other comments still stand: buy GMB or Mazda made in Japan.

Thanks everyone. Managed to drive it home after filling the cooling system back up. Didn't have any temp fluctuations during the 30 minute drive so the pump must still be pumping fine.

orx626 wrote:Auto+ don't sell water pumps toward the horrible end of the scale. I don't believe GMB pumps are to be low quality.... Áuto+ has sold and installed hundreds over the last 8 years. If they were problematic Auto+ would have changed manufacturer/supplier than risk warranty claims and re-work!

You guys still do awesome work Danny, the quality of the pump I purchased was still much better than the one that I took out. I have a feeling the one I got from the guys last year was a Protex though? Blue box. I'm still crossing my fingers that I didn't seal the gasket properly. Cheap fix!

manga_blue wrote:It'd be a good idea to have a bit of a check to make sure it's not something in the motor that's making the pumps fail. Have a look and make sure all the pulleys run straight and true and the belt runs smoothly. Also check belt tension aganst spec: Mazda's spec is 8-9mm (new belt) or 9-10mm (old belt) deflection between the alternator and the crankshaft under a 10Kg load.

Good idea. I had a look this morning at idle and I think the harmonic balancer may have a slight wobble to it.

I still haven't managed to get a closer inspection of it yet (I've degreased as much as I can at the front but I still can't see much past the intake haha), but I'm preparing an order from amayama of a few things so it looks like the ute will be my ride to work for a while!

Not related but...

I have noticed that a few waterpumps on a couple of engines I've pulled down have been rubbing on the cylinder wall. One of these engines died from over heating. There is a little circular wear mark on the cylinder wall where the rotor has been touching. When installing put a bit of bluetak on the center of the water pump rotor and double check there is no rubbing. I think some of the after market pumps stick out a bit further than they should.

Giving up on this engine. I've got some bits donated by friends to put it all back together so its working again - however I've had the opportunity to acquire a b6 from an Auto-na6 for $200. New pump and timing belt, the engine is known to me, it already has the manual cams put in to it. Pretty much a no brainer with a turbo on the cards haha.

Thanks for all your help guys.

One of these days your car is going to give up on you. It has seen more action than a 70's porn star

Thats the great thing about the old girl. We may have been through hell and back, but she knows I'll do what it takes to keep her going! And she does her best to not break alllll the time

I may be a bit late to this conversation, but I'll add a couple comments reflecting on my years of screwing things up. One way I've killed a water pump early is by over-tightening the water pump belt. The belt should have some slack in it. Not a ton, but some.

The other thing is to make super sure you've taken off all the old gasket material. Since you've got no funny noises happening that would be my guess. When I replaced the pump on my MX5 a few months ago I almost did just that and put the new gasket on top of the old gasket. That'll fail every time.