Question: Metal in oil filters?

[Dad]

There has been some chatter on the net about C7 engine failure due to metal in it's oil filter. If this is so what is the C7 filter number and is there any recall on those that might have "metal" in them? . Why in the world would there be metal in an oil filter with the only machined part being done before it is assembled??? Machined meaning shavings cut, not stamped, molded, formed, or coined.

 

[kpic]

That is odd as GM has a cleanliness specification same as where I work.

http://gm-avtovaz.ru/files/treb_en/Supplier_Quality_Statement_of_Requirements.pdf
This is document which points supplier (internal or external) at what is expected. If we had access to GM's ISO/TS 16949 it would be a collection of Standards. Typically, there is a cleanliness specification which documents what is expected and each engineering drawing documents documents what is acceptable usually by a particle count.

http://www.iatfglobaloversight.org/docs/GM_Customer_Specifics_October 2010_rev101101.pdf

I don't work for GM; however, I know what to search for.

Engine manufacturers have a "green test" where clean oil is run through an engine and filtered as it comes out. Kinda of the final test of the cleanliness spec.

 

[Hib Halverson]

This "chatter on the net" about LS7s failing due to metal in filters....

Post a couple of URLs where you've read this chatter. I'm doing some research on the LS7 and reading that might be helpful.

 

[Bob Chadwick]

http://m.autoblog.com/2014/09/08/car-and-driver-corvette-stingrays-lt1-v8-engine-trouble-report/

 

[Vettehead Mikey]

So one event accompanied by a broad assumption of the metal's source should equal a recall? :ugh

 

[Dad]

This "chatter on the net" about LS7s failing due to metal in filters.... Post a couple of URLs where you've read this chatter. I'm doing some research on the LS7 and reading that might be helpful.

Not sure where you got the LS7 worked in here??? Most of the chatter came from news release "replies" to the LT1 C7 engine failure and some blogs. Car and Driver uncovers trouble with Corvette Stingray's LT1 V8 - Autoblog 2014 Corvette Stingray Blown Engine Issue | GM Authority Car & Driver 2014 Chevrolet Corvette Stingray Engine Failure Could Become More Common - Torque News PeterMJ's Corvette C7 Stingray Exposed Stingray Corvette Problems/issues New Corvette Stingray Suffers Total Engine Failure After Just 6,000 Miles

 

[Dad]

So one event accompanied by a broad assumption of the metal's source should equal a recall? :ugh

Not sure why the filter should not have a recall request but to its credit, GM acknowledges it’s aware of the problem and is "analyzing its manufacturing process for a root cause." Taken from carbuzz.com

 

[Hib Halverson]

Not sure where you got the LS7 worked in here??? Most of the chatter came from news release "replies" to the LT1 C7 engine failure and some blogs. Car and Driver uncovers trouble with Corvette Stingray's LT1 V8 - Autoblog 2014 Corvette Stingray Blown Engine Issue | GM Authority Car & Driver 2014 Chevrolet Corvette Stingray Engine Failure Could Become More Common - Torque News PeterMJ's Corvette C7 Stingray Exposed Stingray Corvette Problems/issues New Corvette Stingray Suffers Total Engine Failure After Just 6,000 Miles

Totally sorry.

I misread part of the OP.

It's possible GM had a run of defective filters. No doubt a few engines will get replaced but I doubt we'll see widespread failures.

 

[motorman]

the new corvette engine uses a oil filter with the filter bypass valve built into the filter so there would some metal like a spring involved.

 

[kpic]

The oil filter in this particular 2014 Chevrolet Corvette Stingray was faulty in a way that allowed small particles of metal to break free and enter the engine lubrication system. Once these tiny fragments of sharp metal worked their way through the engine, they became lodged in the bearing assembly of one of the connecting rods and over time, this caused the bearing to wear quickly. Once that bearing was no longer providing the smooth travel which it was designed to support, it was only a matter of time before other components began to fail. - See more at: Car & Driver 2014 Chevrolet Corvette Stingray Engine Failure Could Become More Common - Torque News

The implosion called for a complete replacement of the LT1 V8 (under warranty), and General Motors says that they are currently reviewing their manufacturing processes, to ensure that this fluke won’t affect other models.
Read more: 2014 Corvette Stingray Blown Engine Issue | GM Authority

There are two oddities here; the first is defective oil filters and the second is contaminants in the engine in the first place.

PPAP or Production Part Approval Process (http://en.wikipedia.org/wiki/Production_part_approval_process); the short form of PPAP are samples are measured and tested. As cost can range from a few thousand dollars to tens of thousands of dollars; PPAP is not a cheap date. The process requires monitoring. What that means is GM is not monitoring the supplier

As I mentioned in my first post, it is odd the contaminants were present in the first place. In today's world, each component of an assembly's cleanliness is verified.
On a low mileage engine, it shouldn't matter if the oil filter was bypassing because the debris should not have been there in the first place.

Anyone in the automotive sector in Engineering, Quality, etc. knows the above.

 

[Hib Halverson]

the new corvette engine uses a oil filter with the filter bypass valve built into the filter so there would some metal like a spring involved.

ALL screw on oil filters with internal bypass valves have metal springs, not just the ones on LT1s.

Also, the information above suggests that the metallic debris came from the oil filter, itself, and did not "start" from elsewhere in the engine.

That said, "kpic" might be surprised to find out how much contaminants end up in the oil filter early in an engine's life. Debris left over from the casting process and microscopic pieces of metal left over from the machining process go though the engine in the first few hundred miles. Most of this stuff gets trapped in the filter in the first few hundred miles of engine operation.

This is why I change oil filters at 500 miles on new engines. It's also why if you have the engine's first crankcase of oil analyzed some of the contaminant numbers will be slightly high. Once the engine has been though its first oil change the levels go down.

 

[catbert]

I change the oil on my new cars at 1,000 miles. I've never failed to find metallic residue in the filter oil and drip pan - sometimes a lot, sometimes not. I've never seen REALLY big bits, but enough that I crawl under the car soon after delivery and refill with Penzoil Platinum.

 

[Mac]

Of all cars to have a major engine failure, why does it have to be the Car & Driver long-term tester that packed in? Oh, that's definitely going to leave a mark.

Mac

 

[Hib Halverson]

I change the oil on my new cars at 1,000 miles. I've never failed to find metallic residue in the filter oil and drip pan - sometimes a lot, sometimes not. I've never seen REALLY big bits, but enough that I crawl under the car soon after delivery and refill with Penzoil Platinum.

I'm totally with Catbert on this. I change the first filter at 500 miles and the first oil change at 1000. That's usually when I switch to a premium synthetic, either Gibbs Driven LS30 or Red Line.

I usually cut the first filter open for a visual check and, like Catbert, I've never found any significant metal debris but I have found slight amounts of contaminants–stuff you need a magnifier to see. I just chalk it up to the engine factory environment. Two things happen with new engines: 1) it's virtually impossible to have the assembly process completely free of all contaminants. GM's engine plants come close but the engines are not completely devoid of teeny-tiny pieces of stuff left inside the engine. 2) the vibration and movement of the major parts of the engine–keep in mind, here, we're talking movement in hundreds-of-thousandths of an inch–can dislodge debris left in the pores of the metal during the casting process.

All that stuff goes into the oil and ends up in the filter during the first few hundred miles of use.

 

[kpic]

That said, "kpic" might be surprised to find out how much contaminants end up in the oil filter early in an engine's life. Debris left over from the casting process and microscopic pieces of metal left over from the machining process go though the engine in the first few hundred miles. Most of this stuff gets trapped in the filter in the first few hundred miles of engine operation.

This is why I change oil filters at 500 miles on new engines. It's also why if you have the engine's first crankcase of oil analyzed some of the contaminant numbers will be slightly high. Once the engine has been though its first oil change the levels go down.

Hib,
In the 1970s engines were tested in a green test cycle to remove such contaminants. Clean oil was fed in, filtered externally and removed. As some components rotate entirely on an oil film making no contact with the mating component any contamination could be destructive or as you read catastrophic. To identify where the contaminants came from; the filtered debris can be analyzed by the Met Lab who issues a report defining the contaminants and their volume. Warranty returns are scrutinized also; not to fix blame but to fix problems. Part cleanliness is and was a big thing.

Note, I am defining processes by an employer I left in 1990; not a process of my current or other prior employers. That means what I am describing is a 24 year old process; the criteria is a lot tougher today.

Today, companies have cleanliness specifications. Engineering measures the internal surfaces of the component, next the media (in this case engine oil) is selected, and weight of the allowable filtered contaminants is communicated to the supplier. Warranty costs money which eats significantly at the bottom line.

What is seen at the first oil change was washed from hard to reach areas. High mileage geared components, such as a manual transmission will get a metallic paste at the bottom of the case. In OTR applications, there are magnets to collect the metal paste.

You write for a living and I do design engineering. As I do this stuff 8 hours a day; it is doubtable if I would be surprised.