Sudden loss of oil pressure - potential causes?
#61
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+1...As you can see below, I've owned quite a few sports/sporty cars and just as many mundane sedans and trucks and never, ever, I have I had an indy shop or a dealership screw me over. There's too much at stake for those that are honorable establishments.
#62
Burning Brakes
Thread Starter
I'm generally an advocate of working these things out face to face (in an adult way). Go to the shop and speak directly with the boss. Ask directly "what's going on here?" If he has a shred of decency he'll tell you. If not his evasiveness will be apparent. You did the right thing taking it back to that shop because as soon as you take it somewhere else you provide them with an avenue of deniability that the third party did it. People make honest mistakes, sometimes with expensive consequences. It's how they handle them that counts.
The individual overseeing the problem (semi-hands on) has a good reputation within the P-car community down here - and that community is very small. This is specifically why I have not mentioned the shop or the individual(s). If they are not at fault and this really is a one-in-a-million freak occurrence, I do not wish to tarnish their reputation.
If they are at fault - even if that fault is found by another shop - I do not believe it would be professionally possible to deny liability given the aforementioned nature of the community.
That said; after having met with the individual in question; it does not, in fact, appear that the oil pump is functioning. Whether this is due to a failure of the pump, itself, or the shaft, know one will know until the case is split.
The lines and tubes do not appear to be blocked and the tank (although not visually verified) reportedly also holds oil without issue.
"Why" the pump is not operating is the mystery.
Either way; the engine needs to come apart. Only then, I suspect, will the cause of the failure be known. As this is a standard "perk" of 993 ownership, I can't say I was not prepared for the work, but I was hoping to get at least another 25,000 miles out of the car given the excellent health of the motor - sans what is seemingly the only 911 oil pump failure in the history of the universe.
Some solace, I suppose, can be taken from the probability that, at 75,000 miles, everything should be able to be refreshed with little difficulty.
My usual mechanic and the individual at the shop in question know each other well and will likely be in touch this week. I have communicated to the subject shop that I would like my usual guy - who is obviously far more familiar with the car - to look at it before any work is performed, regardless of location and/or scope.
So, as of this writing, just about everyone is pretty much scratching their heads; but at least the *reason* for the lack of pressure in the engine has been identified.
During the interim period, the mental, "while we are in there" list continues to grow.
I'll probably start another thread to that end, with a different title, so as to attract those who have already gone through the process.
Will also update this one when something worthy of communication occurs.
Thanks all for your advice; thoughts; etc... and I just ordered my first set of Hoosiers.
#64
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Sorry to hear it's gotta be split open prematurely
Keep in mind that there's a wire basket surrounding the pump inlet foot, so you're probably looking for something small enough to get past it and into the pump that could have been introduced during the last service. I'm not sure what the wire mesh size is. Maybe your usual wrench can tell you...
Keep in mind that there's a wire basket surrounding the pump inlet foot, so you're probably looking for something small enough to get past it and into the pump that could have been introduced during the last service. I'm not sure what the wire mesh size is. Maybe your usual wrench can tell you...
#65
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Take a look through the engine teardown section of my website...lots of pictures of how the oil pump is connected to the layshaft through a spline, etc.
http://www.pcarworkshop.com/index.ph...ump.2FLayshaft
I do not want to freak you out, but ff something has failed that results in ANY metal fragments, that will require a complete flush of all the oil lines (including the ones running to the front of the car), the oil radiator, oil thermostat, everything. Some people replace the front radiator if there are metal particulates in the oil because its very difficult to get clean.
The oil pump itself is quite simple, so its difficult to see how it could fail other than losing a tooth.
Definitely please post any pictures you can take of the teardown and source of the problem.
Cheers,
Mike
http://www.pcarworkshop.com/index.ph...ump.2FLayshaft
I do not want to freak you out, but ff something has failed that results in ANY metal fragments, that will require a complete flush of all the oil lines (including the ones running to the front of the car), the oil radiator, oil thermostat, everything. Some people replace the front radiator if there are metal particulates in the oil because its very difficult to get clean.
The oil pump itself is quite simple, so its difficult to see how it could fail other than losing a tooth.
Definitely please post any pictures you can take of the teardown and source of the problem.
Cheers,
Mike
#66
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The wire mesh looked quite fine if I remember. However, that is for the scavenge side of the pump ; the main pressure side is a direct feed from the tank to the pump. No filters/mesh there :-)
#67
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print copy of workshop manual page 141 section 17.26.38
Remove both pressure relief valves from pump. ( These are two tiny pistons that sit in pump core seated by springs. The pistons open each at certain pressure, horizontal @ 9 bar, vertical @ 5.3, but check both. They are mounted with spring, sleeve, retainer etc. Forget one tidbit and piston opens and stays open and little or no pressure)
To remove the small piston themselves, you need a pencil thick flexible magnet.
Remove both pressure relief valves and remount exactly as in picture page 141 in W Manual.
I wish you luck
Remove both pressure relief valves from pump. ( These are two tiny pistons that sit in pump core seated by springs. The pistons open each at certain pressure, horizontal @ 9 bar, vertical @ 5.3, but check both. They are mounted with spring, sleeve, retainer etc. Forget one tidbit and piston opens and stays open and little or no pressure)
To remove the small piston themselves, you need a pencil thick flexible magnet.
Remove both pressure relief valves and remount exactly as in picture page 141 in W Manual.
I wish you luck
If one of the above relief valves is mounted awkwardly, pump does not pump.
big filthy pump test, is to remove small filter and crank without DME
good luck
#68
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That has been checked, correct?
#69
Burning Brakes
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Step ahead of you.
Mucho pictures will be taken - I'm sure just about everyone is curious.
Small filter detached, feed line plugged and creative use of a mirror and flashlight. No movement and no mess. I was praying to be doused in oil but had no such luck.
#71
Burning Brakes
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#72
POACB
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I was told that some turbo owner's experienced oil pressure issues with Mahle filters, but that it didn't affect NA vehicles as much. After hearing this, (similar to non-oem drive belts and misfires,) I always insist on Porsche filters, as the additional cost is negligible. Just another data point for you.
Maybe Steve W. can elaborate.
Maybe Steve W. can elaborate.
#73
Burning Brakes
I read the same thing about the filters, so on my last change I made sure to switch back to Porsche filters. I always cut the filters open and from my eye the Mahle looks better constructed. Maybe whoever was making the Porsche filter back in the day did a better job, but the ones I got were made in the USA with a cheesy sticker plopped on what looked like a Wix filter. I will probably switch back to Mahle next change. JMO.