heinrich

Belt is not broken or skipped. '85. New belt, pump and rollers installed about 1500 miles ago. Tension light came on yesterday eve and soon the car started humming from the passenger's belt cover area (or so it sounded). Temp seemed to climb a little abnormally but not severely, hit the top mark with original 83deg thermostat and rad switch.

Tensioner perfect, full of oil
Tension perfect
belt has several rubber-burn blotches like something stuck on the back of it and it rubbed
Big roller shows apparent wear
Water pump roller has lost all anodising on the roller suface and has long rubber pieces on it, appears belt slipped on it
belt runs toward the very front of the lower rollers and against the crank gear blocking washer (big flat thin metal one)
belt runs 1mm away from front of cam gears
all gear surfaces good, belt teeth side perfect
water pump turns freely by hand, seems to have no play
tensioner roller has no play but tensioner has play fore-aft (bushings and pivot bolt new at tbelt job time)

So .... despite the fact that the water pump turns freely now, the rubber that has come off onto it leads me to believe the pump roller must be seizing someimes (perhaps when the engine gets hot)?

Any experienced opinions would be appreciated.

Lizard928

Heinrich, I am sorry to hear this, however I would have to say that the waterpump had been siezed, best to call the company that you purchased it from, and make sure you get alot of pics, and if the pump had frozen it would have made the tension at the tensioner loose enough to bring the light on.

heinrich

Thanks Colin I am unsure what the prob is but at this point it does look like the pump ... I doubt Devek would have a prob replacing it if I found it faulty.

Lizard928

I would have to concure, but definatly get pics and post them, or e-mail them too me,

that must bite big time, both sharks are down, and the 911 has the CIS issues, speaking of which, if you want to bring the 911 up here after the snow flies I will fix it for you aat no cost just being able to drive it around abit

heinrich

Deal The 911 seems to have fixed itself but there is stil a slight hesitation that is rhythmic and increases with revs, but not at idle ... See you in the spring Colin.

heinrich

I have burnt rubber twice now in it ... after owning it for over 3 years that is so trippy!!!!

Lizard928

ok sounds good, oh hey speaking of which, what happened with those fenders, were you able to use them, and tell Jon I will have pics of the pieces he wants soon, I have been very busy on the farm

H2

I'm concerned by the number relatively NEW waterpump failures that I've been reading about on the various 928 lists. Is there a pattern or a trend? Plastic impeller? Metal? Porsche OEM? Aftermarket rebuilds? Certain rebuilder? Or?

If there's a common denominator here and someone is turning out a bad batch of pumps, or inconsistent in quality, then we probably need to figure that out since the damage done by a seized water pump can (too often) be very pricey for the unfortunate 928 owner. I don't know if a poll would be fair to the vendors who are at the mercy of the pump rebuilders but it's a concern. New pumps or new rebuilds shouldn't be failing this quickly. Are 928 pumps rebuilt by highly sophisticated companies with good quality control or done in Bubba's garage? My chebby, Toyotrash & Subarat pumps give out too...but I do get a predictable number of miles on them before they fail.

Harvey

PorKen

Glad to hear it kept in cam sync!

Bolt, rubber seal (thermostat seal?), or other foreign body in coolant which caught in impeller?

Lizard928

I guess he will let us know when he gets it apart, and hopefully nothing got in there as that could have damaged his block.

heinrich

i haven't removed the pump but it looks fine. the rollers have severe wearing in the direction of movement ... WTF?? Everything is right but the belt runs on the very edge of the big roller (actially over) ..... and I think it's pushing against the edge of the pump's roller lip too.

Bill Ball

Heinrich - What was the source of the WP? I share Harvey's concern.

Big Dave

Good luck heinrich...sounds like you caught it before a disaster occurred.

Old & New

Bill,

Re-read post #3.


heinrich,

IIRC, belt riding at edge of pulley indicates misalignment... a la Big Dave.


Hughett,

"Is there a pattern or a trend?" Yes... people replacing perfectly good pumps at every TB service. (It felt like a good time to chime in with my feelings on that. )

Garth S

Three cheers for the 24 year old orriginal pumper in my '80 - we're doing a little endurance test: I'm beginning to think the pump will win!