Diesel Oil, or "Here we go again!"

I'll probably get heavily flamed for this story, but here goes anyway:

Since I bought my 2003 Jetta TDI, I've used the correct VW-spec oil in the ALH engine with each oil service. But 5,000 miles ago, I found myself in a dilemma: Engine was due for an oil change, we were campground hosting miles from the back forty with no approved oil anywhere to be found, and no time to spend searching for some. Plus extremely poor internet service, let alone getting it delivered.


I remedied the situation by using Mobil Delvac 1240 that I carry on the RV to feed it's engine - a 450 hp Detroit Diesel 8V92T. Yup, 12 liters and 1400+ ft.lbs of torque back there, just a wee bit more than the TDI. It's a straight 40wt with a 0.80% sulfated ash content, and an API (now retired) CF-2 rating. (You can buy the same oil at a Detroit Diesel dealer's parts department under their "Power Guard 40" label.) This oil is formulated for the HD two-stroke engine, one which the mains and connecting rod bearings never get a "rest" between power strokes, unlike a Cummins, Cat, a current generation Detroit, or even our beloved TDIs get. And, yes - I did install a new oil filter at the same time.

Since I'm coming due for another oil change at 235,000 miles, I thought I'd share some things I've noticed while running the "wrong oil" for my engine:

1) It doesn't blow blue smoke out the exhaust when first started. Factory-spec oil killed lots of mosquitos until the engine warmed up.

2) It still starts easily (I live in temperate climates year-round.)

3) It has not used ANY oil at all over 4900 miles. With the VW-spec oil it nearly always was down a quart at oil change time.

4) The engine seems to be quieter, not as much clatter.

So that's my story. I doubt that I've done irreparable damage, but thought others might be interested in what happens in a light-duty diesel when it's fed heavy-duty diesel oil.

Let the flames begin!

I would love to see an oil analysis to show the wear patterns on this oil. You may be the only person to ever try this in a VW diesel.

Im a fan of using “real” Diesel engine oils in our cars. A quality synthetic CJ-4 or CK-4 will perform better, hold soot in suspension and prevent wear better than any 505 oil can. With that said, SAE 40 is really too thick for an ALH. DD 2 strokes shear oil so multigrades aren’t recommended in these applications. It’s also CF spec which is ancient.

Thicker oils tend to quiet engines. No surprise there.

Thicker oils also reduce valve stem leakage, so less smoke at startup and less consumption.

Monogrades generally are less volatile, so less consumption as well.

You may get the same effect if you try an SAE 30, there are some synthetic monogrades, which would be more suitable for the turbocharged ALH.

Just for whatever it's worth, many years ago a member in Ontario with a then MK IV had the oil changed to correct VW specs, at 10,000m had the oil analyzed at a lab. Result oil was still 100%. Had it analyzed at 20,000m again at the lab and result was the oil was still 100%. Then at 30,000m had it tested again and the oil was still good.


So why some people are so anal if they go a bit past the "due" date is beyond me?
Nothing bad will happen if you extend the oil change by a few thousand m/km!!!

That oil should work fine until you encounter cool weather. I'm in agreement with JettaPilot, the correct spec oil doesn't just expire at exactly 10k. I've extended the oci to as much as 15k while traveling.

Hmmm. . .

Maybe I'll just change the filter and pull an oil sample, something I do regularly for the big DD. Will also be interesting to compare samples between the four-stroke VW and the two-stroke DD. . .

Turbo - I live in the RV full-time and "snowbird," staying in 60-80 degree weather year-round, so I don't think cooler weather will be an issue with the Jetta.


FWIW. . .

Honestly, you should have used a CF-4 or newer spec oil. But as long as it didn't blow up....

Jetta_Pilot said:

So why some people are so anal if they go a bit past the "due" date is beyond me?
Nothing bad will happen if you extend the oil change by a few thousand m/km!!!

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The best part, it looks like he is using 5k OCI's.

I've used 20% synthetic Lucas oil additive in our '98 Jetta TDI along with Mobil One 5W-40 Heavy Duty Diesel Oil, and oil consumption dropped.

belome said:

The best part, it looks like he is using 5k OCI's.

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That's not how I read it. In any case, hopefully he does send in a sample for analysis, and reports back with the findings.

Mine will be at 20,000 in 6,000 miles will be testing and then Designing to continue or change


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When TDIs were launched in the mid-90s VW didn't spec synthetic oil. However, they found the non-synthetic was developing coke on the top piston ring (allegedly because of its proximity to the combustion event) "freezing" the ring and causing excessive oil consumption. They switched the oil requirement to synthetic and the 505.00 spec.

So one fill with single weight non-synthetic may have been OK, but continued use may be risky.

You should Only use the proper spec and Viscosity Oil it calls for on Your engine I Only use dealer spec 5w30 Castrol Professional Oil & filter in my 2012 TDI $50.00 for Oil & another $17.30 for Oil filter at Local VW. i could use mobile 1 esp at $15.00 a liter but the dealers is cheaper and its proper oil & filter i change Oil & filter myself at 5,000 km's because its equiped with a turbo and i want to extend its life. but thats me many will argue that there extending there oil changes 15-20,000 just keep in mind. the Oil filter is in bypass mode at that mileage so its no longer filtering oil

but letting dirty oil back into Your engine. and if its a equiped with a turbo your jeperdizing its life span by wearing it out earlyier than normal. Oil is still cheap to buy vs buying an engine or turbo unit. many examples online of people pushing there oil changes well beyond the life of the oil change rec. with a disasterous & expensive $$ outcome.

5k km oil change intervals? Somebody has been reading the Jiffy lube brochures.

tdiman said:

Mine will be at 20,000 in 6,000 miles will be testing and then Designing to continue or change


Sent from my iPhone using Tapatalk

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I regularly took my '98 Jetta TDI to 20,000 miles between oil changes.

I switched to synthetic oil in my big rig Volvo truck with 12L Volvo engine which had a 20,000 mile dino oil change interval, and I took one oil interval to 130,000 miles using oil analysis and changing the three (3) oil filters every 30,000 miles. Save a BUTTLOAD of time & money!

johnsTDI said:

You should Only use the proper spec and Viscosity Oil it calls for on Your engine I Only use dealer spec 5w30 Castrol Professional Oil & filter in my 2012 TDI $50.00 for Oil & another $17.30 for Oil filter at Local VW. i could use mobile 1 esp at $15.00 a liter but the dealers is cheaper and its proper oil & filter i change Oil & filter myself at 5,000 km's because its equiped with a turbo and i want to extend its life. but thats me many will argue that there extending there oil changes 15-20,000 just keep in mind. the Oil filter is in bypass mode at that mileage so its no longer filtering oil

but letting dirty oil back into Your engine. and if its a equiped with a turbo your jeperdizing its life span by wearing it out earlyier than normal. Oil is still cheap to buy vs buying an engine or turbo unit. many examples online of people pushing there oil changes well beyond the life of the oil change rec. with a disasterous & expensive $$ outcome.

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Changing the oil every 3,000 miles is silly and a waste of resource$. If you’re doing it to reassure yourself then I’ve got some bad news for you...

I wish I would have used a different oil on my ‘09 buyback Jetta. Those 2.0 TDIs shed lots of iron because VW used main injection to supply fuel for Regeneration of the DPF and it washes the oil off of the cylinders. I never tried a 5w40,10w40 or 15w40 Real Diesel oil but I’m sure it would have resisted the cylinder washing better than the 5w30 507 oil they tell you to use. VW finally figured it out with the 2015s.

If you don’t believe me install a magnetic drain plug on your oil pan. It’ll blow your mind how much metal is on there. It’s all grey cast iron from the cylinder walls.

CleverUserName said:

Changing the oil every 3,000 miles is silly and a waste of resource$. If you’re doing it to reassure yourself then I’ve got some bad news for you...
I wish I would have used a different oil on my ‘09 buyback Jetta. Those 2.0 TDIs shed lots of iron because VW used main injection to supply fuel for Regeneration of the DPF and it washes the oil off of the cylinders. I never tried a 5w40,10w40 or 15w40 Real Diesel oil but I’m sure it would have resisted the cylinder washing better than the 5w30 507 oil they tell you to use. VW finally figured it out with the 2015s.
If you don’t believe me install a magnetic drain plug on your oil pan. It’ll blow your mind how much metal is on there. It’s all grey cast iron from the cylinder walls.

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Listen to what You Just wrote

Jetta_Pilot said:

Just for whatever it's worth, many years ago a member in Ontario with a then MK IV had the oil changed to correct VW specs, at 10,000m had the oil analyzed at a lab. Result oil was still 100%. Had it analyzed at 20,000m again at the lab and result was the oil was still 100%. Then at 30,000m had it tested again and the oil was still good.
So why some people are so anal if they go a bit past the "due" date is beyond me?
Nothing bad will happen if you extend the oil change by a few thousand m/km!!!

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im not fond of Getting Oil Analyzed because it wont tell You the true condition of piston bearings. if Your thinking of pushing Oil&filter to 20-30,000 usa mile intervals thats asking for trouble. because theres no Oil filter on the market that will keep filtering past around the 7,500 usa miles it will go into bypass mode and not filter anything in bypass mode its letting all dirty diluted contaminated Oil thru the Filter into Your engine is that worth it? really.? Your better off spending the lousy $75.00 on proper spec oil & filter than to sit back and risk & watch the engine wear down to crap. fresh oil Preserves engines not contaminated dirty extended oil changes.

I thought it was the crankshaft springs that were most vulnerable. Jokes aside, that bit about the filter going into bypass is horse manure. It would take many tens of thousands of miles for that to happen. Or using an oil much too heavy for the ambient temps.

johnsTDI said:

im not fond of Getting Oil Analyzed because it wont tell You the true condition of piston bearings. if Your thinking of pushing Oil&filter to 20-30,000 usa mile intervals thats asking for trouble. because theres no Oil filter on the market that will keep filtering past around the 7,500 usa miles it will go into bypass mode and not filter anything in bypass mode its letting all dirty diluted contaminated Oil thru the Filter into Your engine is that worth it? really.? Your better off spending the lousy $75.00 on proper spec oil & filter than to sit back and risk & watch the engine wear down to crap. fresh oil Preserves engines not contaminated dirty extended oil changes.

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“Piston Bearings” LOL.

What I said was 100% true. I had that Jetta for 10 years and changed the oil myself every 7500-8000 miles. My Jetta has the same engine architecture as yours. I actually did have the oil analyzed so I knew that 507 oil was only good for that mileage in my driving cycle.

Unfortunately VW 507 oil is unable to protect the cylinder walls and prevent washdown. I believe a more robust oil would, however I never tried it out because VW bought that car back. If I owned another CR 2.0 TDI I would never use a 507 oil in it based on what I’ve learned.

And the truth is, fresh clean oil does not lubricate as well as oil that has been in the engine for a couple thousand miles. Yes it’s true. Wear rates always spike after an oil change, then trend downwards as the interval progresses. Eventually the oil will start to oxidize and thicken, and wear rates will increase. It is best to change the oil right before the base number is depleted and oxidative thickening occurs, which is typically 10,000-20.000 miles for a quality synthetic non low-ash oil. Some synthetic oils like CI-4+ Can go to 30,000+ with oil monitoring.

Filter loading is dependent on environmental conditions, oil,air and fuel quality. It takes along time for a filter to load up and go into bypass as you describe. If this was actually happening the filter media would be deformed and possibly torn. If I was going to double the oil change interval to 20k miles, I’d be changing out the filter at 10k and topping it off. I’d also inspect the filter pleats to how loaded up they are. If it was lightly loaded perhaps 20k on a single filter would be doable.

johnsTDI said:

if Your thinking of pushing Oil&filter to 20-30,000 usa mile intervals thats asking for trouble. because theres no Oil filter on the market that will keep filtering past around the 7,500 .

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If oill analysis say TBN # is greater than 1/2 fresh oil and soot level is not too high (i.e. does not hinder oil flow due to too high of a viscosity) tou are good to go!

As far as oil filter goes, as long as it is not so clogged as to decreasing flow resulting in too low of oil pressure, you are good to go then too.

Clean diesel engines along with USLD, plus much better oils result in MUCH cleaner, much longer lasting oils than 40 years ago. The days of the 3,000 mile oil change are LONG dead & gone!

I also thought dino oil was bad for the turbo bearings.....

POWERSTROKE said:

I also thought dino oil was bad for the turbo bearings.....

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mineral Oil is a hydrocarbon Oil that sludges up easy and provides less protection than using a Quality synthetic Oil

1 of our members here goes way over 20,000 and he is a Mechanic!

johnsTDI said:

You should Only use the proper spec and Viscosity Oil it calls for on Your engine I Only use dealer spec 5w30 Castrol Professional Oil & filter in my 2012 TDI $50.00 for Oil & another $17.30 for Oil filter at Local VW. i could use mobile 1 esp at $15.00 a liter but the dealers is cheaper and its proper oil & filter i change Oil & filter myself at 5,000 km's because its equiped with a turbo and i want to extend its life. but thats me many will argue that there extending there oil changes 15-20,000 just keep in mind. the Oil filter is in bypass mode at that mileage so its no longer filtering oil

but letting dirty oil back into Your engine. and if its a equiped with a turbo your jeperdizing its life span by wearing it out earlyier than normal. Oil is still cheap to buy vs buying an engine or turbo unit. many examples online of people pushing there oil changes well beyond the life of the oil change rec. with a disasterous & expensive $$ outcome.

Click to expand...

Wow, I bought the same Castrol oil at Walmart, 5 quarts for $21. Why anyone would buy oil and other non-dealer only parts from a stealership is beyond me.

'lectricjeff said:

Wow, I bought the same Castrol oil at Walmart, 5 quarts for $21. Why anyone would buy oil and other non-dealer only parts from a stealership is beyond me.

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are You sure its Same castrol oil Your talking about theres 2 types
-Castrol edge 5w30 Professional (for European vehicles meets the 507.00 spec) for my 2012 TDI.
and then theres this one below
-Castrol edge 5w30 (for north american gas engines.) does not meet spec for use on my 2012 TDI.
https://www.walmart.ca/en/ip/castro...pEifIu9d01e6VjMF9QIMvpwwrMviz3D0aAiIXEALw_wcB
https://germanoem.ca/edge-professional-ll03-5w30-engine-oil-946ml-castrol-g0521952q-cas.html
See the difference now.?

Are you sure it said certified for VW 504 / VW 507 ?

If anyone is unsure on what spec Oil they need you can go to Carquest weblink v2 and look it up there its always spot on.
weblink.carquest.com/Weblink_2_0/login.jsp

username is joecash12
password is joecash11

johnsTDI said:

mineral Oil is a hydrocarbon Oil that sludges up easy and provides less protection than using a Quality synthetic Oil

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Hey smart guy. All synthetic oil is hydrocarbon based, even the GTL pure plus stuff. The only other choice are the Bio-based oils like Biosyn which still has some hydrocarbon constituents.

CleverUserName said:

Hey smart guy. All synthetic oil is hydrocarbon based, even the GTL pure plus stuff. The only other choice are the Bio-based oils like Biosyn which still has some hydrocarbon constituents.

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hey smart guy synthetic oil yes can contain up to 30% mineral oil as base stock but the rest of the 70% is synthetic man made wich is why? price is a little higher to purchase the answere is a no brainer would You not agree. ? outdated mineral oil eventually will be absolete synthetic is far more superior many vehicles from factory come already factory filled using synthetic dude.

johnsTDI said:

hey smart guy synthetic oil yes can contain up to 30% mineral oil as base stock but the rest of the 70% is synthetic man made wich is why? price is a little higher to purchase the answere is a no brainer would You not agree. ? outdated mineral oil eventually will be absolete synthetic is far more superior many vehicles from factory come already factory filled using synthetic dude.

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Synthetic base oils like GTL, PAO, Group III, Visom, Etc... are all made from hydrocarbons. Do you understand?

The only base oils not made from hydrocarbons are vegetable oil based and/or organic sourced group V Lubricants like Biosyn.