Horrible Duramax Aftermarket Filter Mod

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476
Location
Florida
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Regulars probably know I own a towing company and a full service repair facility. Had a young man come in with his father with a new-to-him Chevy 2500 with a Duramax—need brakes all the way around. Suggested an oil and fuel filter change bc the OLM was indicating due and since they bought it used and had no maintenance records suggested doing fuel filter with the oil change. They declined my suggestions because they told me they had just ordered an oil filter adapter plate for the Duramax enabling them to use a Caterpillar oversized filter. https://mddperformance.com/products/cat-oil-filter-adapter-kit This allows the use of a 1R-1807 on the Duramax. The father and son believed the factory filter and oil quantity was undersized. I strenuously advised against this modification for the following reasons: —stick with OEM / Duramax 6.6 has been on the market well over a decade, I can't remember exactly, but we are probably if not at then very close to 15 years of production now. Never once has GM, despite other upgrades, changed the capacity of the oil pan or increased the filter size. I would give the D-Max "Work-Horse" status. It's been a great engine. There is simply no data or anything to indicate the oil capacity or filter is undersized. None. —after a quick Google search the Cat 1R-1807 has no anti-drain back. The positioning of the filter housing means oil can and will drain back out of the oversized filter leading to reduced oil at start—which is proportionally where most engine wear occurs. —although I have no direct oil filter studies I can find to substantiate this....there is empirical evidence from multiple types of different filter media that dirt attracts dirt. In other words, it well known a slight dirty or dirty but not to capacity filter be it water, air, vacuum cleaner....anything.....is more efficient than a virgin new or lightly loaded filter. Filters filter best once collecting dirt. In my opinion, over-sized filters although providing more filter area actually are less efficient overall because of the above dirt attracts dirt effect. —The truck had around 225k miles. I suggested at this age and mileage any possible benefits (which I don't believe there are any benefits) would be too little too late at the truck's age and mileage. Knowing the father and son as regular clients and knowing he was saving up for this truck and money is tight I assured them the better spent money would be doing a full maintenance on the truck of all fluids I.E. oil, filter, fuel filter, transfer case, differentials, transmission and coolent. The previous owner did not have any maintenance records. They left very confused but I'm hoping they cancel the oversized filter kit. The only reason I can ever See an oversized filter being beneficial is if running extreme OCIs. Even extended OCIs are no problem for OEM sized premium filters like M1, Ultra, Royal Purple ect. I think to oversized a filter would take a very specialized operation maybe like mining where you run 24/7 for a said duration and the only time maint could be accomplished was using a shut down of the operation. What say you? Boards have been slow so I figured this would be a good discussion topic. I also directed them here to the "Bobber's". Finally, the family has been a long time client of my shop and I offered to do a free pre-buy inspection before they signed the deal. Just to muddy the waters I suggested a gas truck for the son and not diesel but boys will be boys I guess. I also suggested a Ford 6.7. I think the Duramax is a good engine but my experience has proven for my use the Fords hold up much better IMO. They got overly excited and bought this truck without taking advantage of my free inspection offer. IMO a mistake but hope it works out for them. They are good peoples.
 
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1,701
Location
Michigan
I'm with you. I want to say that running an oversize Cat filter is a solution looking for a problem, but the lack of an ADBV may cross off the "solution" part of that equation.
 
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2,176
Location
Flaherty, KY
I use oversized filters when they're available, but I don't go out of my way to do it. If there's a common, readily available size that has the same thread pitch, gasket size, bypass, etc. and there's available space in the vehicle, I use it. Good example is the PF52 vs the PF47, two perfectly compatible filters but one is a bit longer. Why not use it? That said, I wouldn't go out an buy an adapter or modify the car/truck to do it. On a used vehicle (especially a 200k+ one) my #1 priority would be to get old fluids out of there and replace. Then go over suspension & bushings, belts, pulleys, hoses, all the wear items that might be neglected. Doing so can be the difference between a reliable daily driver and a car that leaves you on the side of the road.
 
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494
Location
Saint Nazianz, WI
I actually did something similar to this only with a fuel filter on a 2006 Jeep Liberty CRD I owned years ago. Some aftermarket retailer offered a kit to swap out the factory fuel filter setup for one from CAT and on a whim I decided to buy and install it. It was a poor decision because I had nothing but issues with fuel pressure after that and frankly came to realize that there was no way to know if the mod had any beneficial effect. It was just modding for the sake of modding looking back on it now.
 
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415
Location
Southeast
I've seen enough people running those for long enough that I don't think it'll hurt anything, but I also don't see much benefit. The OEM filters and an oil change every 5 to 7.5k is all these engines need. The L5P calls for an oil change every 7,500 miles, 300 engine hours, or once per year in a bulletin addressing the 2019 trucks oil life monitors not working correctly. Another thing to note is that the 01-19 engines have a bypass valve built into the oil filter mount/cooler as well as the OEM filter. In theory running a filter with no bypass built in shouldn't hurt anything. The 2020 L5P that uses the new, smaller filter does not have a bypass valve built into the filter mount/cooler. There is only a bypass valve in the filter.
 
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2,504
Location
wv
The Young man with the duramax will eventually get a tuner, 5 or 6 inch exhaust, FASS and possibly stacks coming out of the bed. Lift kit, and probably install a K&N air filter.. if not your shop then probably another.
 
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217
Location
Cali, USA
I'm not a mechanic, but I am mechanically inclined and find watching repair videos fascinating. One of the channels I watch is Gale Banks on YouTube. He's had a series over the past few months on "killing a durmax". Mind you, he's not just strapping this thing and to a dyno and laying its guts on the floor. He is systematically finding the weak points and upgrading them. His goal is 1000 HP at 3500rpm on a stock platform, and he's getting darned close to it! It's a very interesting series, and the tech and thought behind every single upgrade he makes is on full view for all to see. At any rate, In this whole series, I don't recall him upgrading the oil pump or relocating the filter. It might have happened, but I really don't think so, because his goal is to ONLY upgrade the parts needed to gain the power and durability he's looking for. Everything about the base engine is stock, he's so far only played with injectors and turbos. He just recently upgraded the cam, but this is the first internal he's changed. Still running the stock head gaskets and bolts.
 
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4,621
Location
Fort Worth, Texas
My LBZ Duramax has over 400,000 miles & 20,000 engine hours running mostly stock Delco PF2232 filters.....I don't see any benefit to a Caterpillar filter. Even the stock (Updated) Racor Fuel Filter is really good as I haven't had any Injector failures yet..., Though it has been a little hazy in cold weather the last couple winters.
 
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5,831
Location
Texas Hill Country
Interesting choice of a car for a kid. Diesel pickup with a quarter million miles and no service history or sense. I'd bet doing brakes all the way around on that thing is north of $1000 for a shop to do it.
 
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476
Location
Florida
Thread starter
Originally Posted by JustinH
Interesting choice of a car for a kid. Diesel pickup with a quarter million miles and no service history or sense. I'd bet doing brakes all the way around on that thing is north of $1000 for a shop to do it.
Nahhh. Rotors and calipers were fine. Just slapped on new pads. I don't turn rotors anymore. Haven't in years and years. That's detrimental to the rotor's longevity and pure profit for the shop. We just mic the rotors and if the customer doesn't report any pulsating when applying brakes and the rotors are within safe specs just slap on new pads. I never change rotors on my tow trucks unless they are noticeably warped or are out of spec. Same for customers of my shop.
 
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7,830
Location
Champlain/Hudson Valley
Your vantage point and story telling was complete and interesting. Thanks. I wonder what their considerations were, if any. Used trucks have always been red-flaggers. And you have no details regarding the source of, the intended use of and price of this truck? Must've looked clean. I bet the diesel sold 'em.
 
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9,986
Location
Waco, TX
Originally Posted by A_Spruce
Gale Banks..... Everything about the base engine is stock, ......, but this is the first internal he's changed. Still running the stock head gaskets and bolts.
That insane.
 
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