SwayBar

Everyone, that's one very fine lookin' woman, and a real sweetie too!

I agree with everyone who says to clean out what you can, pop in a new pump, and have at it. At this point, you have nothing to lose and everything to gain.

You have nothing to lose because if you do try the new pump and the motor is dead, well, you confirmed that you needed a new motor anyway.

On the other hand, you have everything to gain because after the clean-out and installation of the new pump, the engine may run fine 'forever', thus not have to bother with pulling the engine, rebuilding another, and putting the rebuild back in. That's a lot of frickin' work, not to mention pricey.

Another outstanding issue are the missing teeth off of the timing belt and whether that caused any problems.

hacker-pschorr

Thanks for the moral support guys. Thinking back just over a year ago the most I've ever done on a 928 was an oil change. Now I've remove / replaced the clutch 10+ times, changed the clutch master, head gaskets etc... Who said Porsche's are hard to work on?

Well, I had a few beers and then slept on it. It's going back together as is. This car has not oil cooler lines so there is not much between the pump and filter to clean out - making the job that much simplier. I'm leaving for Road America tonight so this will have to wait until Monday. Good news is my 79 is still in Elkhart Lake so I can drive that around all weekend.

What I think I'm going to do (unless anyone thinks this is stupid) is clean everything out the best I can - install new pump & 8ish quarts of cheap oil. Then with the oil filter off - use my drill to turn the pump and pump all of the cheap oil out through the oil filter port. My only fear is if the bypass switch is closed - it will circulate through the engine. I'm not 100% sure how that switch works so that might be a monkey wrench in that idea.

First thing I checked was cam timing - it was 100% dead on. Enough of the teeth were left to turn everything and stay in time.

Jim R.

Damn that sucks! You are taking it better than I would. Hopefully for the few seconds of low/no oil pressure there was enough of a film to keep the wear to a minimum.

Jim

Imo000

Looks like it all came off in one piece. Maybe there is a small part of the corner that is missing. Just replace the pump and flush the system. If you can, perhaps insert a flexible handled magnet through the drain hole and try to pick up any metal that dropped down into the pan.

hacker-pschorr

Not a bad idea - cannot hurt anything.

Normy

What do you think caused this? I don't recal reading about a seized oil pump before, though I'm sure its' happened to someone. Was your oil pressure good before this happened?

Excessive heat? Age?

N

hacker-pschorr

Normy - I found 3 threads where other 928's experienced oil pumps stopping suddenly. None of those threads went anywhere so I have no idea what caused their issues.

Who knows, maybe duirng my rebuild I dropped something into the pan, just took this long for the sump to suck it up?

DFWX

The oil starvation damage might be minor enough. However, you might want to figure out how to oil up the bearings before starting after re-assembly because when it fires you are suddenly at 1,000+ rpms on already dry bearings (and rings)....
Leading to my question - who would a person pre-oil a motor? On American V8 you pull the distributor and run a shaft down it as the distributor shaft also runs the oil pump...
Stuff like this is really disheartening and your claim, rational approach is almost super-human.
Mark O

hacker-pschorr

Mark,
When I installed my heads last fall - I filled the crankcase then used a 90 degree drill & 15mm (I think) socket on the oil pump - worked like a charm. I plan on doing the same once the new pump is on. You could tell pretty easily when the oil hit the pump - drill went from spinning full speed to about 1/4 speed.

Bill Ball

On start up, the filter is bypassed for a while, right? So filter position in the system may not be terribly relevant.

Jim bailey - 928 International

Simply replace the pump and run it the filter will catch any debris all oil goes through the filter all the time except when the filter is blocked , very high pressure. Also be very sure you get the correct oil pump they DO NOT all interchange. I have heard of a few such failures no idea how it happens.

hacker-pschorr

I'm finding conflicting answers on this doing searching through the threads. Looks like they might be tempurature controlled, so on a 90 degree day (like yesterday) the oil may have been warm enough to have been going through the filter - only reason why I've been thinking about this is the hope whatever caused this was sent to the filter after breaking the pump.

I plan on removing those switches and cleaning them out just in case.
PET illustration 104-00: 44-47 & 48-51. My car does not have the cooler so I do not have to mess with those lines or cleaning out the cooler.

hacker-pschorr

Your site lists 80-95 for the oil pump. So is it the early pumps may not fit a newer engine but the newer pumps should fit the older ones after 1980?

Murphy has a pair of S4 motors I can take pumps from - Jim Page also has a pair of 4.7 engines with pumps.

Jim bailey - 928 International

our websight is AH ..Well ... Ahm ....lets just say 99 and 44/100 pure.... we based that on Porsche's information so go by the casting numbers on the pump. The difference is an oil path to remove pressure from the shaft seal but the blocks do not all have a machined relief for that passage so the wrong pump in the wrong block and it will blow out the shaft seal...Sometimes several times in succession That takes a while to figure out !

hacker-pschorr

Ok, so as long as the "new" pump matches the design of the old pump I sould be good to go. So there is there a casting number on the pump?

Cool - good to know.

How about this theory: Maybe the shaft seal / bearing was going bad allowing the gear/impeller (whatever that thing is called) to wobble and hit that little bridge piece - eventually breaking a chunk off and taking it with it?