Marine Blue

One of those situations where extreme situations expose weak spots on our cars components. Judging by the responses maybe a new water pump modifications need to be implemented to improve reliability even if it results in a higher parts price. I know I would prefer a reliable part to avoid self distruction and potential engine rebuild.

SharkSkin

OW! John, that's really painful to look at. Sorry to hear of this.

I'd be looking at pinning the pulley and the impeller, then swaging the pins in place. At least it would be rebuildable...

FlyingDog

At least the block should be fine since the pump spins normally. I was actually impressed with how well the belt survived. It has some nice slices in it from passing over the flanges on the pulley.

Instead of the usual way of using a perpendicular pin, how about a parallel pin (or even better, a set screw) between the shaft and pulley? It would effectively be keying the shaft.

John Veninger

Thank you Mark. I'll be sure to take up up on that offer once I know how many are no longer straight.

I do see 968 intake valves are a bit lower in price than they were a few years ago.

Bill Ball

Right, the hole in the shaft would be shallow - just enough to secure the tip of the pin and prevent the pulley or impeller from walking. For ease rebuilding/removal it could be a screw-in pin. Of course, that's not the way they are made so it would not be acceptable as a core, but after catastrophes like this and many others that have been reported here, it just seems to me like a very good idea to reduce the likelihood of this. That or the damn thing should not be press fit but rather bolted on like most other even less important pulleys. TT bearing carriers should be pinned or set-screwed as well.

Mike Frye

Bill,

Do you know of any other cases where this particular thing happened? I don't remember seeing the pulley come off the shaft like this.

Bill Ball

You're right, this is the first time I have heard of the pulley doing this.

There have been numerous instances of the plastic and metal impellers walking. The damage to blocks from a loose metal impeller is well-documented. Even with a plastic impeller walking, with no damage to the block, the shaft can move forward accomplishing essentially what we see here. I've personally seen one that was caught before the belt was damaged. Circlip fixing of the shaft position would have been a helpful feature too, as on the early automatic TT shafts and on the main tensioner roller. Even if the pulley or impeller don't walk and allow the shaft to move, the effects of overheating from a non-functional pump have killed a few motors. You hope to catch that before it happens, but at least a few have not.

When you look at the "bare essentials" design of the Porsche WP, you wonder how they have the nerve to ask $600 for it.

Big AL in VA

Soory to here what happened John. Now I know why Beerfish called and asked if I had a spare pump. I got to see you drive one of the qualiffying laps at SP. I'm the guy his Girlfriend parked behind your car when you were trying to back up. Sorry about that she was not thinking.
If I can be of any help let me know. I live in Fairfax.

It felt really good watching your 928 lap at SP, for this I thank you.

Last year I damaged a head and was pissed off and debated selling. And it was the support here on Rennlist that kept me goin. I am sure you have a ton of support here.

Big AL in VA
84 Euro 928 S2 twin distributor monster

Jim bailey - 928 International

Bill..."When you look at the "bare essentials" design of the Porsche WP, you wonder how they have the nerve to ask $600 for it."
Ah, there is a bigger question ...lifted from an article from couple years ago ..." In fact, a current study has discovered that Porsche earns an average profit of $28,000 per vehicle sold. What this means is that with each Carrera that rolls off the lot, they have enough money to buy a couple of Pontiacs of their own.

That $28,000 figure "dwarfs the per-car earnings of virtually any other automaker." By comparison, BMW makes about $3,200 per car, whereas Audi gets about $1,580. When you start looking at higher volume vehicles, the figure drops even further, with Chrysler only making $900 and VW netting $400...."
Porsche has never been shy about markups... Their brand name commands a premium and perhaps is part of why so many people WISH they had a Porsche...

IcemanG17

John
That makes me sick just thinking about it.....PAINFULLY sick....damm

Hopefully when you open it up its better than it seems!!!

mark kibort

looks like you were running some good times before it died. too bad.
It also makes me sick to think of the work needed based on this kind of stupid failure.
nice to know these waterpump rebuilds are just crap shoots with 3 modes of failures.

mk

tomcat

John was catching up to the lead, and quickly, before his engine quit. And he had a couple slower laps before the engine totally gave up.

Thanks for the effort John. Sorry, a lit'l

Bill51sdr

I seem to recall that "Loaded", i.e. Fausto had a similar failure with a waterpump practically right out of the box. Fortunately for him he caught it before any real damage was done. I am sure that thread is in the archives somewhere.

Panzer9

All things considered, it was a great day at the track- loved seeing the Shark bombing around SP. It was like a T-Rex among Raptors! We even had a nice dinner afterwards, some beers, and all sorts of automotive topics of conversation. Good luck John- you'll get the old girl back in the fight soon enough.

JPTL

Beyond me too. Also, when that No.2 car forced him to drop a wheel off the track coming out of the carousel, John took it in stride. I'm not sure that I could have.