Mori, you know me better than to quote from an owner's manual. I'm trying to dumb-it-down for JoePassatOwner. 503.01 is the long-life spec, 502 is based on 1998 A3 and is an older spec. 10,000/5000 seems like a rational recommendation. I'd also skip the filter change at 5000 and use a sump pump.
So what really causes sludge?
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Hey Audi Junkie, I checked the OCI for '97, '02, and '04 A4 and S4 models. Regardless of whether it's a normally aspirated A4 or an A4 turbo, the OCIs were:
'97, 7,500 miles
'02, 10,000 miles
'04, 5,000 miles
Due to the sludge issue, Audi seems to have categorically cut the OCI in half.
I still have not heard from anyone if any US Audi is prepped for LongLife service (with the flexible service display,etc). Doesn't look like it's the case with a 5k mile OCI. I don't see any reason to use a VW 503.01 oil instead of VW 502.00 with a 5k or even a 10k mile OCI.
'97, 7,500 miles
'02, 10,000 miles
'04, 5,000 miles
Due to the sludge issue, Audi seems to have categorically cut the OCI in half.
I still have not heard from anyone if any US Audi is prepped for LongLife service (with the flexible service display,etc). Doesn't look like it's the case with a 5k mile OCI. I don't see any reason to use a VW 503.01 oil instead of VW 502.00 with a 5k or even a 10k mile OCI.
Did they really reduce the OCIs for 2004? I know they went back to the first oil change at 5K, but after that it's every 10K miles, AFAIK.
epolk ,I agree with you .The oil, the engine and how it is used all come in to play .I am sure that the chemical reaction is always the same.
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Quattro Pete wrote:
So, does Audi specify VW 503.01 oil for any US model, or is it VW 502.00 throughout the model range? Are any US Audis on LL service intervals yet?
Yikes! You're right, Pete. Sorry, the OCI is still 10k miles, only the first oil change is scheduled for 5k miles. I used the source you gave me over on AW, but I guess I had my beer goggles on -- or I was simply tired when I checked those PDF files.
So, does Audi specify VW 503.01 oil for any US model, or is it VW 502.00 throughout the model range? Are any US Audis on LL service intervals yet?
That's a good question. It'd be interesting to actually get a hold of an owner's manual from a new Audi to see how specific the oil requirements are (maybe the folks on the B6 forum could provide it?). My '01 manual is very vague/broad in terms of oil specs. It just says to use API SJ and/or ACEA A2 or A3.
I have a feeling they still don't mention any of the VW specs. That 'sludge' warranty extension letter that AoA sent out to customers (the one that A4NCAR is talking about) is probably the first piece of documentation that mentions the VW specs by name, at least with regards to the A4.
I believe AoA required a VW 505.01 spec oil for the RS6 and that info was in fact in the owner's manual. No idea about other Audis though.
I have a feeling they still don't mention any of the VW specs. That 'sludge' warranty extension letter that AoA sent out to customers (the one that A4NCAR is talking about) is probably the first piece of documentation that mentions the VW specs by name, at least with regards to the A4.
I believe AoA required a VW 505.01 spec oil for the RS6 and that info was in fact in the owner's manual. No idea about other Audis though.
The only required oils in USA are 505 TDI and RS6 505.01 (?). Now with '04.5 1.8t cars get bigger filters and I believe FREE "synthetic" changes. AFAIK, Moss-Magnusen Act requires a specified oil be provided free during warranty period. That's probally why Audi could not specify VW 502 or even "synth" because they decided not to provide it free. Obvious error. Anyway, non-turbo Audis like Mori's saw 7500 for the norm oci and 1.8t saw 5000. Audi was the first manufacturer to provide inclusive service in 1987 and does it still now. They provided 1.8ts 5000 mi inclusive services until 2001 when they went to 10,000 as an obvious cost-cutting measure. This is the point VW needed to specify VW 503.01 or at least 502 and provide it free at 10k. Big mistake. Did AoA realize how bad API drum oil is in turbos? Why could they not standardize dealer oil for 1.8t? Would any oil company now want to get involved with Audi after this looming tragedy? Imagine all the Passat owners that came from a low maintenance Camrys and did not realize how high-tech the B5 chassis w/1.8t is. My cousin came from older VW Jettas and Foxes that you could abuse. Whoa is she after a snapped timing belt and a sludged oil pump. 1.8t is being replaced with a 2.0 for next year.
Forgot to mention what a good plan an oil extractor is for those long dealer ocis. Pump it out halfway at 5000 miles and use the same kind of oil to refill.
[ October 24, 2004, 07:01 PM: Message edited by: Audi Junkie ]
Forgot to mention what a good plan an oil extractor is for those long dealer ocis. Pump it out halfway at 5000 miles and use the same kind of oil to refill.
[ October 24, 2004, 07:01 PM: Message edited by: Audi Junkie ]
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Actually, my '96 US Audi manual does point out that VW 500.00* is the required spec "when driving in Europe." It goes on to say that's due to the higher speed limit. To me, this was a clear indication that a VW 500.00 approved oil was in fact THE oil to be used.
*For those not familiar with VW oil specs: VW 500.00 has been superceeded since by VW 502.00.
I am pretty sure we will soon see an increasing number of VW approved oils.
*For those not familiar with VW oil specs: VW 500.00 has been superceeded since by VW 502.00.
I am pretty sure we will soon see an increasing number of VW approved oils.
The 2001 Passat 1.8T owner's manual specifies a 5K mile = 8K km oil change interval with EITHER 5W-40 (preferred) or 5w30, and EITHER synthetic or dino. I used Castrol GTX 5w30 on a 3K mile = 5K km / 6 months schedule before I got the infamous sludge notice; I now use Mobil 1 0W-40 on the same schedule. Overkill? Perhaps, but my cam chain tensioner has gotten noisy on hot idle.
LOL! Since Audi pays for the oil changes, they recommend 10K mile OCIs for Audis. But since the customer pays for the oil changes on VWs (most of them anyway), they tell them to do it every 5K miles. I just love these double standards.
The requirements for sludge are heat, particulate contaminants, and moisture.
What happens is that particles of dirt (which may be products of the decomposition of the oil itself), sulfur, and blowby are bound together with moisture.
The conditions for the formation of these sludge precursors include certain oxides in the blowby - characteristic of lean burn engines, low volatility fuel, improper venting of the crankcase, low temperature operating conditions, low crankcase capacity, and long drain intervals, all of which increase the amount of sludge precursors and binders in the motor oil.
They then undergo chemical reactions which may involve decomposition, the formation of acids, and ultimately polymerization.
These reactions are promoted by higher temperatures when the precursor-bearing oil comes in contact with the pistons and cylinder walls and with modern high temperature cylinder head designs. The precursors adhere to particulates, they begin to aggregate, and then polymerize.
Sludge can be prevented by filtration, avoidance of low operating temperatures, proper maintenance of the crankcase ventilation, frequent oil changes, and the use of motor oils with additives and blend stocks that disperse sludge binders.
One of the things noted in the early days of synthetic motor oils was the absence of sludge formation. It turned out that the breakdown of the mineral oil itself was a contributor to sludge, something that improved base stocks and additives has greatly alleviated.
I can envision an automobile operated with a marginal mineral oil in primarily short-trip driving with extended oil change intervals becoming a sludge precursor generator, which coupled with new cylinder head designs results in the precursor-laden oil being subjected to high temperature and pressure as it lubricates the cylinders and overhead camshaft.
This seems to be the scenario at Toyota and VW, where sludge problems followed design changes that raised cylinder head temperatures and recommendations for extended motor oil drain intervals.
Thanks for all the feedback/insight everyone.
More technical then my brain can absorb, but informative nonetheless.
As with VW oil approval, I'd still stick with a VW503.01 and keep with my extended drains (10K). I've done it for 8 years with over 225K miles between 3 VW/Audis 1.8t's, (using synth only of course, but not always approved oil), and it's been working fine.
Also, I think the mention of exclusive use of VW 505.01 in the RS6 was a mistake on Audi or AoA's part. I thought it was said that the VW503.01 was for this app. not the 505.01 (meant for TDI instead)? I could be wrong, but that is what I heard from a pretty reliable source looking into the whole VW/Audi approved oil ordeal. Another thing is that the approved oil list in Europe supposedly differs from the one used/mailed by AoA (since many of the oils are not in the US). And I think that VW502.00 was chosen purely for customer convenience (beign able to find it at a local auto parts store). Anyways, I'm confident with the use of the Motul 8100 E-tech 0W-40 for extended drains. No worries here.
As with VW oil approval, I'd still stick with a VW503.01 and keep with my extended drains (10K). I've done it for 8 years with over 225K miles between 3 VW/Audis 1.8t's, (using synth only of course, but not always approved oil), and it's been working fine.
Also, I think the mention of exclusive use of VW 505.01 in the RS6 was a mistake on Audi or AoA's part. I thought it was said that the VW503.01 was for this app. not the 505.01 (meant for TDI instead)? I could be wrong, but that is what I heard from a pretty reliable source looking into the whole VW/Audi approved oil ordeal. Another thing is that the approved oil list in Europe supposedly differs from the one used/mailed by AoA (since many of the oils are not in the US). And I think that VW502.00 was chosen purely for customer convenience (beign able to find it at a local auto parts store). Anyways, I'm confident with the use of the Motul 8100 E-tech 0W-40 for extended drains. No worries here.
MolaKule
Staff member
Sludge essentially is any useless hydrocarbon molecule that has lost its ability to protect the engine.
In answer to your question, sludge is any hydrocarbon or polymer that has been "voted off the island" by oxidation and acidic procsses.
Oxidation is generally a process that involves the introduction of oxygen into the oil and additives by heat, moisture, and nitric and sulfuric acids.
See this Interesting Articles thread for more technical information:
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=4;t=000021
In answer to your question, sludge is any hydrocarbon or polymer that has been "voted off the island" by oxidation and acidic procsses.
Oxidation is generally a process that involves the introduction of oxygen into the oil and additives by heat, moisture, and nitric and sulfuric acids.
See this Interesting Articles thread for more technical information:
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=4;t=000021
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