Sean79 5spd

Water pump started leaking so have removed. Seems impeller has been touching block and a small amount of metal has been removed. How serious is this?

Sean

Bill Ball

Almost never serious unless a lot of metal is removed creating a large gap between the impeller and the block. You say a small amount, so you are probably OK. Post a picture if you can. And for academic interest, it would be nice to see some shots of the WP to determine what happened to allow the impeller to contact the block and any history you might have about the WP (when installed, rebuilt or new, Laso or Porsche).

Sean79 5spd

The pump has a sticker "rebuilt by an independnt rebuilder". The casting has a porsche number embossed on it. The impeller is a brass colored alloy. The bearing failed causing the shaft to skew and allowed the impeller to touch the block. Pics attached

I have heard that a pump with a rubber impeller can be purchased, sound like a good idea. Opinions?

Sean

Sean79 5spd

Water pump was replaced in April 97 @ 74K miles by the PO. Current mileage is 110K
Sean

Lizard928

Sean,

You can purchase waterpumps with plastic impellers, it is normally not thought to be a good idea as the plastic impellers have been known to freewheel on the shaft causing an overheating issue.

ROG100

Looks like a Laso casting that has been used in a rebuild.
The more of these Porsche and Laso rebuild failures of the seal cartridge moveing within the casting due to over use of the casting the more I want to go with new!!!

Ispeed

Mine just failed the same way, and my block looks the same. Rebuilt pump (metal impeller) from Int. (15 months and 6k miles)
Needless to say, my S4 that I have spent the last 4 years making nice, now has a bad block. Great!

I really need to read more technical threads and skip the fluff. That is what brought me here in the first place.

ROG100

Nobody else agrees with me but the interferance fit of the seal cartridge within the casting is the biggest issue. Everytime the casting - be it Porsche or Laso or ?? - is reused the fit becomes looser. Thats why the seal cartridge moves within the casting and towards the block. A new - not rebuilt - casting and seal cartridge assembly is the answer.
Just my 5cents

jpitman2

Surely the cartridge could be pegged, located somehow? If you knew how far in to drill, then tap for a grub screw?
jp 83 Euro S AT 51k.

Bill Ball

Porsche went to plastic impellers in 1990. I don't have strong preference. They each have their downsides.

ROG100

I now have a discussion going with GPM (Porsche OEM) and will update the original thread.

Bill Ball

So, you had a considerable amount ground out of the block? And there were no warning signs or sounds this was going on? You know, from the picture in the current case, it looks like it may be more than just a "small amount" too. I'd need to look at pictures of an unmolested block again.