Oil Pump Failure mode?

[Hatdragracer]

I am in process of rebuilding my engine and doing some upgrades (details In SIG).

The old cover seems to be a GM cover. When tearing the engine down I saw this damage in the oil pump and gear. The oil pump shaft wouldn't spin by hand. The oil pump shaft did have play but I did not measure before I took apart.

The story on the motor was that it had about 5k on the rebuild. The car made 10 psi at idle, max of 40psi even at high engine speeds.

I don't want to repeat whatever caused this so any advice would be appreciated. Is this just a normal high mileage failure, contamination, cavitation?

I have a new cover and HV pump from Full Throttle, I plan on doing the mods shown in Mike's 4.1 build thread.

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[bison]

All the lines are from contaminants and the score marks on the filter adapter are from incorrect clearance. I don't rec high volume pumps. They aren't needed in most applications and may cause excessive wear to other components.


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[Buick Mark]

The pump cover and housing look pretty scored. Use new gears (stock length) ditch the high volume gears and spacer, use a booster plate, set end clearance to .002 and you'll be good

 

[earlbrown]

Is this just a normal high mileage failure, contamination, cavitation?

I have a new cover and HV pump from Full Throttle, I plan on doing the mods shown in Mike's 4.1 build thread.

Those marks from from debris going through the pump and tearing up the metal. Is there any chance that the cover in real life doesn't look as bad as it does in the pictures? From the pics it looks like it's shot. With any luck it's not that bad in real life.

From your join date it looks like you've been around a year or so, have you seen this thread? ....
http://www.turbobuicks.com/forums/buick-v6-turbo-tech/39169-how-build-front-cover-oil-pump.html

If your cover isn't as bad as it looks in the pics you might be able to get by doing some flow mods.


....and if you can't afford to get a new filter adapter, this link will show you how to resurface your existing one on the cheep...

http://www.turbobuicks.com/forums/b...66-building-front-cover-oil-pump-part-1a.html


and if your cover is actually as bad as the pics show, it'll take another plan of attack to get you back right

 

[Hatdragracer]

Guys...thanks for the info and the links. After I did the Lesabre gauge conversion I enjoyed the car much less as seeing the oil gauge made me worry....so I don't want to worry about the pressure in the rebuild. After buying the heads, crank, XFI, turbo etc...I think the extra $ and time to get the oil pressure right is well worth it to enjoy the car.

The pics of the cover and adapter make it look a little better....the marks are deep and feel rough to the touch.



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[TLIMITED]

Get Earl Brown's cover and melt that one down!!!

 

[earlbrown]

The pics of the cover and adapter make it look a little better....the marks are deep and feel rough to the touch.

I was hoping you were going to say they weren't as bad as the pics shown


In that case you're got some work to do.... I would start by cutting open the oil filter open and seeings what's in there. With any luck there's no chunks and very little sparkles. If you have a magnetic oil drain plug, drain the oil and take a look at that. Both of those will be good clues on how to proceed with inspections.

If you find ANY evidence of metal contamination, I would strongly recommend dropping the oil pan and taking a looksie. the way the stock pan is built, about 1/2 quart never drains out so no matter how long you let it drip and particulates on the bottom can't run out. (it's also a good way to count timing gear teeth if you haven't replaced the stock timing chain yet)

oops... I just re-read your original post....
You say you're in the process of rebuilding. Have you torn the engine all the way down yet or just removed the timing cover?

 

[Hatdragracer]

Engine is completely torn down....block is at machine shop. Rest of engine looked okay.

No sign of contamination in bores or bearing surfaces. Nothing unusual in pan.

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[earlbrown]

Well it's good that you've got it down to the bare block. On failures like this, it's always best to knock out the cam bearings and oil galley plugs and clean the hell out of everything then build up from there. That's the only way to keep debris from making this happen again.

It sucks that you lost the engine and tore up the cover but I'm surprised that you didn't find anything else on teardown. The debris that scoured up your cover has to be somewhere. Actually, now that I think about it... can you say for sure that the cover wasn't scoured when the engine was built??? That might have been the reason for the HV kit. To pass it off and get it sold.

 

[Hatdragracer]

I don't know for sure when that cover was done, I have only had the car for a year.

And for what its worth, I didn't lose the engine, the engine was running fine other than the lower oil pressure...I just wanted a horsepower upgrade so when I took the cover off to change the cam I found this issue. Although knowing what I do now, I would have not been as eager to go on Power Tour.

The core engine was completely stock other than ARP fasteners, hypereutectic pistons, upgraded valve springs, and a double roller timing chain.

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[hiboom]

welcome to the money pit

 

[earlbrown]

And for what its worth, I didn't lose the engine, the engine was running fine other than the lower oil pressure...I just wanted a horsepower upgrade so when I took the cover off to change the cam I found this issue. Although knowing what I do now, I would have not been as eager to go on Power Tour.

Good call then. You really dodged a bullet. Tearing it down this early probable just saved you the cost of a turbo. Also, if you were running any kind of oil cooler, do not use it when you get the engine back together. After getting it back together the last thing you want is to have a metered grit injector in the oil system!