Latest views on 505.01 oils vs Rotella T6/Delvac 1 for PD cam longevity?

[d24tdi]

I realize any oil choice thread risks opening a can of worms. But I have a few of my PD cars coming due for PM service this winter and I try to check back here every few years on the latest consensus of what results are being observed by those using different oils.

I have been sticking to 5W40 grade 505.01 oils (mainly Pentosin, sometimes LM or Castrol Edge back when I could find it locally) in the PD engines since the prevailing view last time I took a hard look at this was that the 5W40 oils did the best job of preserving cam and lifter life, and the 505.01 rating may or may not matter but cannot hurt.

However, there have always been folks who argued that any good synthetic diesel 5W40 was suitable and they had good results with them... And others who favored non-505.01 oils like that plus additives like zinc, molybdenum disulfide etc.....

I run Rotella T6 5W40 in all my other diesel equipment and am beginning to buy it in 55gal drums this year so needless to say, there is a convenience and cost benefit if I can run it in all of the VWs as well. Especially since I added two more PD cars to my little "fleet" in the last year, replacing old VE cars that got to the end of the road. So even though the 5W40 505.01 has been working for me and my instinct is to keep doing what has been successful so far, I'm motivated now to take yet another fresh look at this.

At this point the PD engines have been on the road in North America for over 20 years, and even longer than that worldwide. Should be a lot of evidence out there. Any updates on what everyone else is doing with these now? Long term experiments showing results? "Settled" conclusions on whether the engines really do any worse on something like T6 vs the 505.01 choices in the same viscosity range?

Not looking for disputes over theory, just facts/firsthand experience over long term operation for those who can share it.

TIA

 

[d24tdi]

Going to page @IndigoBlueWagon here if you care to comment from your perspective as a vendor with some depth and scale to look at trends ---- I just ordered 10 liters of HP2 from you guys for this go-around on my two PDs that are due, but I would be curious to know what you are seeing/hearing from your other customers with PD cars. Still selling a lot of 505.01 or are you seeing folks use other alternatives with success?

 

[Mozambiquer]

It's your car, do what you want, but I would not recommend it. The big piece in the PD that the 505.01 spec is for is shear stability. Shear stability is the ability of the oil to hold lubricity under extreme pressure, which the PD experiences under the lobes of the camshaft. T6 used to have a higher shear stability until they changed the formula because of DPFs, they removed some of the components (metals) which cause ash in the DPF, which are also the same components that help with the shear stability.
There are people who run it, though often they are the same people who say the cams in a PD are junk...

 

[PickleRick]

I've yet to purchase a BHW with sub 180,000 miles on it.

The one that lives in my DD Passat only got t6 for the some 3-4 years i had it on the road. I don't think I ever examined the cam and if I did there wasn't enough wear to warrant worry. She ran great. 36mpg in town and 40 plus on road trips. Plenty of power.

Parked it when the BHW yota hit the road. It got a cam because I wanted it "like new" as it was a restomod build.

2 years and 30k so far far on all t6 since I owned it other than the cam break period of 500 miles.

Did the head gasket a month or two ago, still looked new. Saying a lot being an AMC. Interested to see how long it lasts. If it goes bad again and I can scrap up the cash I'll try one of Frank's cams.

 

[ZippyNH]

Think the bigger question...are you deleted?
T-6 is a great oil but doesn't meet VW requirements as low saps....but is ok for most manufacturers.
So it really more IMHO about VW vs the industry standards with VW trying to be more strict.
As stated...it's your car, do what you feel is important. THIS IS ALL ABOUT SELF-INTEREST .
That's why VW opted to go with a lower SAPS oil, to reduce warranty costs and increase replacement interval of the DPF.
Oils do get reformulated....have heard it's not the same it was to make it more dpf friendly... assuming that this change COULD be harmful..
Feeling lucky?!

 

[burpod]

anecdotal evidence but wifes BEW has 303k on it now, the first cam i used onyl 505.01 (+ one change of vw 506.01 5w30), and the factory came had significant wear @ 105k when i changed the first belt. i put in a stock idparts replacement cam. since then i ran only rotella t6 and mobil TDT - mostly t6. and has run with zero engine issues since. i have not inspected the cam yet, but i will be soon. however, due to a mishap with the DG oil bypass filter return line blowing out, wife drove 25-30mi to work with oil spewing out the whole way and oil light flashing intermittently halfway to work. i went to go pick her up + fix it and found the dipstick dry. i plugged the broken line, filled with oil, and 3k miles later sounds and drives completely normal...

so from my experience, i wouldn't hesitate to use t6 or mobil TDT (or whatever it's called now) in a PD

 

[Lug_Nut]

re: PD cam longevity vs VE cam longevity debate
I found the VE cams to be showing the initial signs of hardness wear-through on the lobe tips at right around 175k miles.
I found the PD cams to be showing the initial signs of hardness wear-through on the lobe tips at right around 175k miles.

ALL my TDI have been purchased used. I didn't always know what oils any prior operation under prior ownership might have been.
My observation above is based on my installations lasting until I changed them out. They'd no doubt continue to "drive completely normal" and would have lasted longer had I not taken the hint and swapped them. I always used the 505.xx that was recommended.

Except once.
Returning from the Portland fest in my AHU swapped cabrio I developed an oil leak that was discovered and remedied well before any low pressure alert. The gas station (Wyoming?) had no 505.00, but had Rotella. Any port in a storm.
When I got home the cam I had installed at the time of the conversion swap was showing the same level of wear as 175k miles with 505.xx, but at far fewer miles.

Nope, that was it for me.

 

[PickleRick]

Think the bigger question...are you deleted?
T-6 is a great oil but doesn't meet VW requirements as low saps....but is ok for most manufacturers.
So it really more IMHO about VW vs the industry standards with VW trying to be more strict.
As stated...it's your car, do what you feel is important. THIS IS ALL ABOUT SELF-INTEREST .
That's why VW opted to go with a lower SAPS oil, to reduce warranty costs and increase replacement interval of the DPF.
Oils do get reformulated....have heard it's not the same it was to make it more dpf friendly... assuming that this change COULD be harmful..
Feeling lucky?!

We don't have a dpf on the b5.5 BHW Passats. Not sure if Europe got any.

 

[caffeine]

We don't have a dpf on the b5.5 BHW Passats. Not sure if Europe got any.

Yes at least the 2.0L PDs in the B5.5 Passats had DPFs in Europe. Not sure about the 1.9s that were available there.

 

[PickleRick]

Our Audi A3 2.0 TDI has a dpf that needs to go away

 

[d24tdi]

Thanks for the replies. Needless to say I know it's my choice with my equipment and I'm not asking for permission to break the rules. I'm not interested in running a risk on this -- but I am interested in assessing whether there in fact is a risk based on the accumulated evidence and knowledge from the real world.

Thus my question was aimed at probing what kind of actual results folks have been having now that these engines are a couple decades old and plenty of long haul owners have been through one or more cam and lifter sets. Anecdotal rather than scientific info for sure, but in field usage, that is often more meaningful than theoretical specs are. Thanks @burpod and @PickleRick for the replies on your own experiences to that effect. Not conclusive by any means but it sounds like the T6 has been working out for you over extended trials.

Shear stability and presumably also film strength are what the PD design needs to survive so I agree it would be logical that those are what the 505.01 spec is intended for in theory. But we all know that cam and lifter failure on cars that got steady diets of 505.01 are all too common. 505.01 rated oils also come in 5W30 and 5W40 weights (maybe there used to be some 0W40 out there as well?) but we have a fair amount of anecdotal evidence to suggest the 5W40 oils give longer cam/lifter life. Does a 505.01 rated 5W30 protect better than a 505.00 rated 5W40? Do the additives or methods used to hit the 505.01 targets last the full extended OCI that many of us here use? Would oil analysis reveal degradation of 505.01 oils to non-505.01 specs after a few thousand miles anyway, if a lab knew what to look for? Improvements to lifter and cam surface durability are in the picture now too, for those of us who are on our second or third cam and lifter sets. All reasons to ask the question.

If there was clear evidence after all these years that, all else equal (the hard part of course!), a 5W40 oil meeting 505.01 spec will protect the wear surfaces better than a similar 5W40 without the 505.01 rating, then there would be nothing to talk about on this topic. But it doesn't seem like that has ever been the case, given extensive anecdotal experience of those who had cam and lifter failure on 505.01 and of those who got long component life without it.

Figured it was worth seeing what others are doing at this point or if any consensus has developed, but it sounds like we're all still where we always have been, running whatever we think will work and having mixed experiences that don't add up to anything conclusive. Makes sense... Perhaps the only way to really know would have been to start some much more controlled experiments 20 years ago then add new groups as lifter surface updates and whatnot came out. Obviously never really could have happened.

I'll probably keep running 505.01 5W40s and keep two types of oil on the shelf, for the PD cars and for everything else, out of abundance of caution. Still curious as to any other views though.

 

[burpod]

my gut feeling has been is variations in metallurgy quality of cams (and lifters) is probably the largest factor. for the first 105k miles i had my 2006, i ONLY used VW spec 505.01, with one interval where i used the also-approved 506.01. had a mild RC tune on it for about 60k of those miles. and cam was fairly wiped by then. virtually no chamfer left on the lobes. oil + intervals were all by the VW book. i do remember hearing it sound a little "buppy" at idle too, toward the end. then 200k miles of T6/mobil TDT running tip-top and tuned up even more, also often going beyond 10k intervals. i did have a DG bypass filter on it, which i've rarely changed, maybe every 50k.

i'm really peeved i had that incident ~4k ago and lost all oil, as that really screwed up my long term test come cam inspection time. now if i see a worn cam, that could have easily come from running it out of oil lol. however of course i'm greatly relieved everything seems fine, turbo and all. it must just barely had enough pressure to get enough lubrication. but so will be interesting to see what the cam looks like. sometime soon i'm going to at least take a peek at it. but given how it's run over 200k with t6/tdt, even after it was run out of oil, is proof enough that t6/tdt are perfectly fine

just my 2cents

 

[MrRobogoat]

One thing that the PD engines have that the VE ones don't is the tandem pump. In theory, there could be fuel weeping in from the tandem pump at a rate not enough to be noticeable, but enough to over time cause cam wear issues. I'd suspect this most for cam wear at the rear of the engine. I'd think oil analysis would pick this up, however.

FWIW, @Windex told me that the cam in what is now my 2005 Passat is original at 405k mi on it, and that he has run Rotella T6 in it. I haven't examined it yet, but have no reason to doubt him.

Now, what really impressed me was how long it took for the oil to turn black after he changed it. On all other TDIs I've had, it was basically instantaneous. Regardless of whether I keep using T6 or go to a 505.01 oil, I have been converted to using an oil extractor that can not only empty the pan, but also get all the oil out of the filter housing. Independent of oil spec / cam wear, changing a larger fraction of the oil in the engine seems like a good thing, and it being easier than rolling around on the ground is a clear win as well.

 

[2004LB7]

I've been meaning to inspect my colt cam at the "next" oil change. I don't have that many miles on it. Maybe close to 40k but was thinking I would keep an eye on it so as to catch any issues early if they were to develop.

I've run T6 since I put the cam in 40k miles ago. So if anything noteworthy happens I'll try and remember to update this thread

 

[caffeine]

I've been meaning to inspect my colt cam at the "next" oil change. I don't have that many miles on it. Maybe close to 40k but was thinking I would keep an eye on it so as to catch any issues early if they were to develop.

I've run T6 since I put the cam in 40k miles ago. So if anything noteworthy happens I'll try and remember to update this thread

Pretty much in the same boat here. Have 32k kms on my Colt cam and have been running T6