Are there symptoms (i.e, noise) when a water pump goes or starts to go bad?

 

In some cases yes, in others no.

If you have any unusual cooling problems, hear any abnormal noises from the pump, if it is leaking, or if there is excessive play in the pump's bearing you know it's time to replace it. If it's already exploded and the impeller bits are all strewn throughout the cooling system at least some shops recommend engine tear down to find those bits, otherwise it could lead to more hotspots and more cracks in the aluminum.

If a cracked head has caused an intermix condition, the intermix residue must be cleaned out of the entire cooling system, otherwise it will eat the hoses, etc. until they are gone.

Stick with the OEM genuine replacement pump, I've personally had problems and have read about issues with the aftermarket units.

 

Thanks! I'm having my car checked out tomorrow by IMA Motorsports, hopefully they check all the common issues.

 

you mean right away?no overheating warning light?

 

If the impeller explodes and/or all of the fins disintegrate yes there would be very little warning. But more than likely before it gets to this point there would be warning signs before that happens in the form of a coolant leak from the pump shaft, wobble or play in the shaft/pulley/belt, abnormal noises/etc.

If the car is already up to temp you are talking about just minutes before it starts to overheat if the impeller were to explode.

 

Unlikely from running rich. I've heard from several sources that the bank 1-3 cracks fairly often after a water pump failure. I'll post a pic of the old head soon with the crack.

 

agree with Logray. A water pump bearing is usually what wears out first. Excess vibrations may or may not be felt. I didn't notice it because I assumed my rumble was from the timing problem. There are probably cases of it failing without vibration occurring, but less common.

Many people believe you should just switch these out every 60k miles. They use a plastic impeller which I personally believe is very stupid. I wonder if there are any metal ones?

 

My head cracked at the inner exhaust valve spring seat on cylinder #1 and there was no water pump failure. I know of many cracks at that valve spring seat that were not related to a water pump failure (also at the inner exhaust valve spring seat on cylinder #6 (which is basically a mirror image of #1).

If the impeller breaks up it can block passages throughout the head. I think that Flat6 now recommends that the water pump be replaced every 50K or so.

 

My only warning was steaming coming out the engine compartment. My engine temp actually never went too high, but I still got the cracked cylinder head. I probably had it running for 2-3 minutes after the first wisp of steam. My fluid was actually was leaking out around the bad water pump.

 

As for a metal impeller, the newest replacement H20 pump from Porsche has a "metal like" impeller. I wouldn't call it metal, but I wouldn't call it plastic. The old one was a plastic polymer of some sort. In any case, certainly an area to monitor on the car, first thing that would probably show up is some sort of leak... but as Doug points out the heads on the older cars can crack even without the pump failure... casting issues.

 

http://www.youtube.com/watch?v=5ComOjlofk8

 

That is the notorious crack in the inner exhaust valve spring seat on Cylinder #1 (or #6). It starts at the seat and then runs over to the spark plug tube. Here are some more pics. These are from several different heads, and I have lots more

 

A "loose" metal impeller can damage the mating surface on the crankcase & then you got BIG problems.

 

Yep I'm pretty much from the same camp, but it's hard to classify what the latest material is.