[STS] Engine Failure - Failed OEM Oil Pump?
05-05-2008, 08:28 PM
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[STS] Engine Failure - Failed OEM Oil Pump?
Before reading further, please be advised that I am primarily making this post to gather competent opinions about the cause of my motor failure. I would really appreciate it if we could avoid turning this into a finger-pointing thread.
That being said, here is the abbreviated story:
My vehicle was the first G35 Coupe to be equipped with the STS Remote-mount turbo in May 2007. The installation was tuned to 356HP at 7PSI. The tune was competent and conservative, and served me well for 9 months.
In February 2008, the platform was significantly upgraded with a new larger intercooler and fast-spooling ball-bearing turbo. The installation was tuned to 370HP at 8PSI. (More on the details of the upgrade in a later post.)
This tune was very conservative as well, and served me well for 2 weeks.
In March of 2008, my motor failed. The morning of the failure, my oil pressure read slightly lower than normal. The dipstick did not read anywhere near low levels, so I continued to drive the car normally. That same night, mid-drive on the way home, oil pressure dropped to zero, and the engine immediately started making a loud clunking sound that increased in frequency with increased RPM.
I immediately pulled over. The engine was not leaking any fluids whatsoever. The engine continued to run, although with drastically decreased power. The next morning, I had the vehicle towed to my mechanic shop, during which the engine started up just fine to move the vehicle onto the truck and the lift. 
Fast forward two weeks. The engine was pulled out, and shipped to GTM for analysis. The block had no holes, and there were no obvious sign of failure outside of the engine. Apparently, the inside is a completely different story. I was expecting a bent rod or damage more stereotypical of FI-related failure. But instead, this is what we found:
Image 565
Image 566
Image 567
Image 568
Image 569
Image 570
Image 571
Image 572
Image 573
Image 810
Image 811
Image 812
Image 813
Image 814
Image 815
It has been suggested that the result of this widespread damage might have been failure of the OEM Oil Pump. According to my brief research, no one has ever experienced this type of failure before.
I am no expert on engine internals, which is why I am opening up this instance to the analysis of the more experienced members of this community.
I welcome your thoughts.
That being said, here is the abbreviated story:
My vehicle was the first G35 Coupe to be equipped with the STS Remote-mount turbo in May 2007. The installation was tuned to 356HP at 7PSI. The tune was competent and conservative, and served me well for 9 months.
In February 2008, the platform was significantly upgraded with a new larger intercooler and fast-spooling ball-bearing turbo. The installation was tuned to 370HP at 8PSI. (More on the details of the upgrade in a later post.)
This tune was very conservative as well, and served me well for 2 weeks.In March of 2008, my motor failed. The morning of the failure, my oil pressure read slightly lower than normal. The dipstick did not read anywhere near low levels, so I continued to drive the car normally. That same night, mid-drive on the way home, oil pressure dropped to zero, and the engine immediately started making a loud clunking sound that increased in frequency with increased RPM.
I immediately pulled over. The engine was not leaking any fluids whatsoever. The engine continued to run, although with drastically decreased power. The next morning, I had the vehicle towed to my mechanic shop, during which the engine started up just fine to move the vehicle onto the truck and the lift. Fast forward two weeks. The engine was pulled out, and shipped to GTM for analysis. The block had no holes, and there were no obvious sign of failure outside of the engine. Apparently, the inside is a completely different story. I was expecting a bent rod or damage more stereotypical of FI-related failure. But instead, this is what we found:
Image 565
Image 566
Image 567
Image 568
Image 569
Image 570
Image 571
Image 572
Image 573
Image 810
Image 811
Image 812
Image 813
Image 814
Image 815
It has been suggested that the result of this widespread damage might have been failure of the OEM Oil Pump. According to my brief research, no one has ever experienced this type of failure before.
I am no expert on engine internals, which is why I am opening up this instance to the analysis of the more experienced members of this community.I welcome your thoughts.
Last edited by goosegoose; 05-05-2008 at 08:33 PM.
05-05-2008, 08:31 PM
#2
i cant believe you found a bunch of red X's in your motor... 
good luck with the build, let us know if we can do anything for you. oil pressure is really tricky in these cars. not usually an issue with a stock motor but who knows when you have to pump oil soo far away from the engine.
good luck with the build, let us know if we can do anything for you. oil pressure is really tricky in these cars. not usually an issue with a stock motor but who knows when you have to pump oil soo far away from the engine.
Last edited by Audible Mayhem; 05-05-2008 at 08:34 PM.
05-05-2008, 08:48 PM
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as bearing clearances open up,oil pressure goes down.if you still had pressure before you tore the motor down it is probably not the pump.somewhere, somehow you started circulating junk though the motor.now you need to figure out what self destructed first and started that chain reaction.did you ever run low on oil?btwy that motor is wasted,sorry to see it
05-06-2008, 05:43 AM
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Originally Posted by Audible Mayhem
they work now for me 
looks like typical oil starvation. the whole motor is ruined and you need to replace it. did you change the oil recently? switch types of oil?
looks like typical oil starvation. the whole motor is ruined and you need to replace it. did you change the oil recently? switch types of oil?
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05-06-2008, 05:49 AM
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Originally Posted by go-fast
as bearing clearances open up,oil pressure goes down.if you still had pressure before you tore the motor down it is probably not the pump.somewhere, somehow you started circulating junk though the motor.now you need to figure out what self destructed first and started that chain reaction.did you ever run low on oil?btwy that motor is wasted,sorry to see it
Oil pressure was present before the motor was torn down, but only before it warmed up. After the motor warmed up to operating temps, oil pressure dropped to zero.
I assume that with such widespread damage, it is nearly futile to try to figure out the original cause of the failure?
05-06-2008, 05:50 AM
#9
Originally Posted by goosegoose
The motor is about 50,000mi old, and have been under FI for the last 10,000mi. I've been feeding it Amsoil or Mobile-1 10w40 for the last two years, with oild changes every 3,500mi or so. The motor has never had an oil consumption issue, and certainly never ran low on oil, to my knowledge.
did you drop the oil pan yourself? did you drain the oil before shipping it?
just wondering how much was in there...
basically three things could have happened...
you could have just had low oil pressure due to the fact it has to send it all the way to the back of the car to the turbo.
you could have hit something that caused an oil leak and ran the car low on oil.
or you could have gotten dirt, RTV, or some sort of junk in the pickup or through the bearings which would let less oil flow through the oil passages and cause it to have low pressure and less flow, causing everything to heat up and ruin every bearing/rotating part...
not ruling out the oil pump but we have done well over 100 stock motor FI VQs in the past year and havent seen one fail...
good luck with your new build. i am sure you are in good hands.
05-06-2008, 06:11 AM
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Originally Posted by Audible Mayhem
you could have just had low oil pressure due to the fact it has to send it all the way to the back of the car to the turbo.
you could have hit something that caused an oil leak and ran the car low on oil.
you could have hit something that caused an oil leak and ran the car low on oil.
Goose,
I know what you have been through and all the $$$$$$$ you have to shell out this past month. To bad you didn't get to enjoy your upgraded kit that much.
05-06-2008, 06:18 AM
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Some food for thought and history on this car..
We did this car as the first STS turbod car in the North East last summer.
Car ran fine for well over 9 months
Customer decided to upgrade the turbo and retune with another shop in CT area
2 weeks following the upgrade the motor blows
Now based on the pictureds shown it looks like one or more of the bearings had went and sent contaminants into the rest of the motor and made its way all the way up to the cam journals, wiping them out..
It could have been caused by a contaminant introduced when the new turbo was installed.
It could have been caused by low oil level after the install
It could have been caused by over reving the engine
However without seeing the tops of the rod bearings, and signs of ptting from obvious detonation, one could conclude that detonation was most likely not the culprit.
The oil pressure upon intital start up and then reducing as the engine oil warmed up, tells a tale of incresed bearing clearances as the engine warmed up..
IMHO most likely NOT an oil PUMP failure.
We did this car as the first STS turbod car in the North East last summer.
Car ran fine for well over 9 months
Customer decided to upgrade the turbo and retune with another shop in CT area
2 weeks following the upgrade the motor blows
Now based on the pictureds shown it looks like one or more of the bearings had went and sent contaminants into the rest of the motor and made its way all the way up to the cam journals, wiping them out..
It could have been caused by a contaminant introduced when the new turbo was installed.
It could have been caused by low oil level after the install
It could have been caused by over reving the engine
However without seeing the tops of the rod bearings, and signs of ptting from obvious detonation, one could conclude that detonation was most likely not the culprit.
The oil pressure upon intital start up and then reducing as the engine oil warmed up, tells a tale of incresed bearing clearances as the engine warmed up..
IMHO most likely NOT an oil PUMP failure.
05-06-2008, 06:21 AM
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Originally Posted by DJ SMITTY
So you continued to let your car run while the oil pressure read 0?
Sorry to hear about that
Sorry to hear about that
05-06-2008, 06:33 AM
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Originally Posted by Julian@MRC
Now based on the pictureds shown it looks like one or more of the bearings had went and sent contaminants into the rest of the motor and made its way all the way up to the cam journals, wiping them out..
It could have been caused by a contaminant introduced when the new turbo was installed.
It could have been caused by low oil level after the install
It could have been caused by over reving the engine
However without seeing the tops of the rod bearings, and signs of ptting from obvious detonation, one could conclude that detonation was most likely not the culprit.
The oil pressure upon intital start up and then reducing as the engine oil warmed up, tells a tale of incresed bearing clearances as the engine warmed up..
IMHO most likely NOT an oil PUMP failure.
It could have been caused by a contaminant introduced when the new turbo was installed.
It could have been caused by low oil level after the install
It could have been caused by over reving the engine
However without seeing the tops of the rod bearings, and signs of ptting from obvious detonation, one could conclude that detonation was most likely not the culprit.
The oil pressure upon intital start up and then reducing as the engine oil warmed up, tells a tale of incresed bearing clearances as the engine warmed up..
IMHO most likely NOT an oil PUMP failure.
Many thanks for the input. I tend to agree with your final conclusion on this. No one has ever seen an OEM Oil pump go bad, and I doubt I am so special to be the only exception.
As you know, I'm also been pretty careful and conservative with the vehicle, so I can rule out low oil negligence and over-revving. Also, my priorities have also been conservative tuning for longevity, and I've never really cared for pushing the utmost limits of HP-TQ numbers.
I believe Sam commented that there was a good amount of carbon with no obvious signs of detonation, but perhaps he can take some more detailed pictures to highlight the areas you mentioned.
05-06-2008, 07:13 AM
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Originally Posted by Ahsmo
Sorry for the OT but..
Goosegoose, who is install and tuning the new motor? Who pulled the old motor?
Goosegoose, who is install and tuning the new motor? Who pulled the old motor?
05-06-2008, 07:21 AM
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Originally Posted by goosegoose
Julian,
Many thanks for the input. I tend to agree with your final conclusion on this. No one has ever seen an OEM Oil pump go bad, and I doubt I am so special to be the only exception.
Many thanks for the input. I tend to agree with your final conclusion on this. No one has ever seen an OEM Oil pump go bad, and I doubt I am so special to be the only exception.
