Changing oil without changing by pass filter

The consensus seems to be that bypass filters need only be changed every second or third time one changes the oil and the full flow filter. My question is how to do this and both:

• Change all of the oil
• Not get dirt and dust in the filter or system

If I just leave the oil in the bypass and change the rest, I don't open the system and introduce dirt but I also don't change all of the oil and I mess up the consistency of my UOAs.

If I remove the element and allow it to drain I run the risk of introducing dirt unless I can figure out how to do this very cleanly in my dusty environment.

I just bled my brakes with a power bleeder and it worked great. I am wondering if I can use it to blow the oil out of the by pass element.

Will it work without damaging the filter?

I could use the power bleeder to refill it too if I could be quick on the shut-off.

Any thoughts? Advice?

I have decided to put the full 12,500 on this oil so I have some time to figure out how to do this right.

Thanks!

If all you are doing are 12,500 miles OCI's, I would ask why are you even bothering?

I run 25,000 miles on Mobil One 5w40 TDT (aka Delvac One 5w40) with no bypass filter.

If I were to intergrate a bypass filter system, I would (if I were a belt and suspenders type) change the bypass @ 50,000 and change the oil @ 25,000 miles. Dont forget the extra qt of oil adds 22% to the OCI. So realistically going to 30,000 miles OCI's (with the bypass filter) would be an absolute no brainer.

I don't know on the car, but on my truck (with bypass filter) I change it every 25,000 which is also when I change the oil.

12,500 is what my UOA suggests is appropriate. I was at .9% soot at 10,750 miles and also had a lot of nitrate (21%). The high soot is probably from my 5 1/2 mile trips to work in the winter where I get warmed up just in time to shut it down. I also do a fair amount of high speed driving in 115 degree deserts with the AC on full tilt. Half of my TBN was gone.

I hate to think what it would be like with no by pass and wussy 505.01 oil!


How would you go about changing the oil without changing the bypass--this is my question. Believe me, I wish it were happening at 25,000 but hell 12,500 is not bad when everyone I know is on the 3500 schedule.

I'll sample again in 10K and maybe there will be better news next time, but in the mean time I'd better go with what my UOA says.

Why just just change both filters at 12,500 then? The bypass filter is what, $20? I know the big one on my truck is only around $35 and that holds over 2 qts of oil.

electrobent said:

The consensus seems to be that bypass filters need only be changed every second or third time one changes the oil and the full flow filter.

Click to expand...

So I'm marching to my own drum beat?
I'd change the bypass element (back when I ran one) many times before I'd drain the sump and replace the factory oil filter.
Oil analysis showed that 60k miles for oil and filter change provided the bypass element was on a 5k mile interval, was good.
Now..... The bypass elements were cheap, under a buck. and I'd add a quart for each two by-pass changes to make-up for oil in the removed element. I was also driving 45k miles a year.
Now I'm down closer to 15k miles a year. The oil is old and wet long before it is dirty so a bypass filter isn't used.

Lug_Nut said:

So I'm marching to my own drum beat?
I'd change the bypass element (back when I ran one) many times before I'd drain the sump and replace the factory oil filter.
Oil analysis showed that 60k miles for oil and filter change provided the bypass element was on a 5k mile interval, was good.
Now..... The bypass elements were cheap, under a buck. and I'd add a quart for each two by-pass changes to make-up for oil in the removed element. I was also driving 45k miles a year.
Now I'm down closer to 15k miles a year. The oil is old and wet long before it is dirty so a bypass filter isn't used.

Click to expand...

You came to that procedure given some set of reasoning. The real question would be (if I understand your drum beat rhythm), what would you oil analysis have shown on (bypass element ) was on 10,20,30,40,50 K cycles? Now.... when bypass elements were cheap.... I have read that the Amsoil bypass filter-2 microns (dieselgeek used to sell them but is now discontinued?) is INXS of $23 per????

BUT the thing you REALLY DID, yet did not discuss was the 1 qt "top up" refreshment EVERY 5,000 miles. So with a 5.5 qt sump (from 4.5 qt) not only did you add 22%, but putting 22% every 5k is HUGE !!!! So in effect you were doing a 22% oil change EVERY 5,000 miles !!!!

Price of EaBP-90

nate379 said:

Why just just change both filters at 12,500 then? The bypass filter is what, $20? I know the big one on my truck is only around $35 and that holds over 2 qts of oil.

Click to expand...

$37.15 for non Amsoil Dealers

Even if you leave the bypass in place, you're draining 4.5-5.0 quarts of old oil. There will be a small impact on the oil analysis results the second time around, but you can easily calculate this effect. You should easily be able to go > 10k miles with the fresh TDT in there.

I wouldn't remove the bypass filter and then try to re-install it. There will be some normal compression set of the elastomeric gasket & it may leak on you, plus it's just not necessary. You can do a quick check of the bypass after 25k miles and see if oil is still flowing through it by how quickly it gets hot, or if it gets very hot at all. Based on this simple check you can determine if the bypass needs to be changed every second or third time you drain the oil. The filter life will depend to a great degree on how much soot is being generated by the engine.

TS

So you are saying to just leave the quart of old oil in place drain the 4.8 that comes out of the pan and refill with 4.8 of clean oil and resample again at 10K?

I guess its either that or buy a new by-pass and replace everything which will cost about $45 more (the filter element and the extra quart of TDT).

Thanks!

Yes, that's exactly what I'm saying...just change the oil and canister filter; leave the bypass filter in place.

Keep in mind that when you switch oil types/brands, it generally takes a few changes to see the best results with the new chemistry. It's entirely possible that your results with the TDT will improve with regards to the level of soot and the TBN left after 10,000 miles. From what I've seen with numerous TDI analyses over the past twelve years, you really should be able to get 15k out of the TDT (and 30k on the bypass filters), with the setup you have.

To save some money, I'd skip the oil analysis the next time around and just change the oil & both filters after 10,000 miles. Then I'd test the third fill of the Mobil TDT after 12,500 miles & see how much margin you have left. This allows you to step the service intervals out to
15,000 miles in a controlled fashion.

I hope that makes sense....

TS

Thanks Too Slick, you just save me $75.

I will check to be sure my by-pass is still flowing and if it is I will change the full flow and the oil that drains from the pan at 12,500 leaving the by-pass and its quart of old oil in place.

10,000 later I will start from scratch with 5.8 qts of fresh TDT and new bypass and full flow filter elements.

10,000 after that I will sample again and figure out what to do from there.
Waiting to sample here also gets me out of explaining the unchanged 22%.

Your logic makes sense:

It is supposed to have 4.8 Qts of mediocre oil and no bypass and go 10,000 miles.

I will be giving it 4.8 Qts of much better oil plus a quart of mediocre oil plus whatever is left of the bypass filter and going 10,000 miles.

The car should be happy.

Thanks again!


I need to figure out what is causing all this soot? New oil, putting around town in the winter, blasting through the Imperial Sand Dunes at 4:00 pm in August, or PD fuel injectors with 150,000 miles of factory fuel filtration? Some combination of the above?

I'd agree the soot should be lower.... If you can find some decent biodiesel blend (B5 or B10), in your area, I'd try that. The biodiesel should keep the fuel injectors clean and lower the soot a bit. I do think the short trips (and possibly worn injector pintles) are the major factors in the # of soot.

TS

I must be getting a deal from teh guy I get mine from. Cost me $35 for the EABP110

electrobent said:

$37.15 for non Amsoil Dealers

Click to expand...

Even if I don't have a cam problem, I still have the problem of buried injectors--no more swapping them out on the side of the road like I do with my 1982 Mercedes 300CD.

I gotta limp these along until its time to do the timing belt in 90K.

But why am I not seeing soot going out my tail pipe?

Its all going in my oil?

Is there a way to check injector wear with Vag-Com?

Fuel flow at idle maybe?

And then there's my 09A with factory fluid 160,000 miles later . . .

I am beginning think that VW put a long-term motor in a disposable car to come up with the TDI.