Camshaft Damage Causes in V6 2.5 TDI Engines

Hello.

"Since this issue has personally affected me, and I don't want to simply accept it, I'd like to ask if there are any logical explanations as to why some camshafts in AFB, AKN, and AKE engines are prone to wear. I've already determined that the problem isn't due to low oil levels, but perhaps there's a connection with the oil specified by VAG. I've always used the 0W-30 LL oil from Q8, and nothing else. As mentioned in another thread, this oil has now been replaced with a 5W-30. Could this be a contributing factor?"
The LL oil I was using, and which is specified by VAG, only met the ACEA A1/B1 standard, while the new oil meets the ACEA A5/B5 standard, which seems to be much "better." Can anyone confirm this? Are there other logical reasons? The camshafts are manufactured by machine; if they were faulty, why don't all of them from a series break down, but only some from different cars? Is it possible to have a (removed) camshaft tested to potentially prove a manufacturing defect and then sue? Does that make sense?

<Activating>

I once read something that suggested the hair-line grades on the rocker arms were "unfavorable" relative to the camshafts. This meant the rocker arms held up well, but the camshafts wore out.

It would be better if you specified the VW standards when referring to oil requirements mandated by VW.
Because it's possible that the oils already met other standards before, but no one bothered to apply for the official certification.
Sure, here is the translation of the text from German to English:

<Partial>

If both oils met the specified VW standard, then you probably didn't do anything wrong, and you can't really blame the oil.

m;

Hi,

Quote:

Camshafts are manufactured by machines, so if there were defects, why wouldn't all of them from a production series fail, but only some from different cars?

From my experience: I don't know any AFB that hasn't had this problem sooner or later.
As I see it: poor material quality + inadequate lubrication.

Best regards, Rainer.

Hi,

Quote:

'only' the ACEA A1/B1 standard, while the new one is the ACEA A5/B5

.

It's probably not due to that. The B5 isn't *that* much better than the B1! Both have a reduced HTHS value of less than 3.5; in practice, the oils are around 3.0.
I certainly wouldn't put any oil in my car that doesn't, at least in theory, meet the B3 standard.
Perhaps AFBs would last longer if they were given proper oil from the beginning, but it's important to remember that even good oil cannot improve poor materials; at best, it can reduce the stress on them.

Regards,
Sure, here is the translation of the text from German to English:

"Micha"

Hi,

Camshafts are manufactured by machines, so if there were defects, why wouldn't all of them from a production series fail, but only some from different cars?
From my experience: I don't know any AFB that hasn't had this problem sooner or later.
As I see it: poor material quality + inadequate lubrication.

Greetings, Rainer

Hello mserge,

Unfortunately, I'm not an expert, just an interested amateur, so I can't say anything about the cause.

I recall a phrase from some VW/Audi promotional presentation about a technically advanced feature, specifically 'the camshafts were manufactured using process xxx for cost optimization.' I remember it because it was a bit unusual – I found it quite amusing.

I thought that the technicians were trying to subtly communicate to other technicians: 'Please don't ask us about this awful thing! We had to build it so poorly because those damned cost estimators were breathing down our necks and forcing us to do it, despite our better judgment!!!'

Unfortunately, I can't find the article anymore, but I believe the text is from one of the presentation excerpts – which were sometimes published on the homepage – from the Vienna Motor Symposium a few years ago.
I'm sorry that I can only speculate here based on my limited memory.

Sure, here is the translation of the text from German to English:

'Hello'
herwig

Hi,
Audi calls it a combination of unfavorable tolerances, which, of course, explains everything...
Years ago, manufacturers advertised both castings and Ledeburit (a hard variant of gray cast iron) as manufacturing processes, but they did so without specifying the type of engine they were suitable for.

LL was not a topic for the AFB in 1998; it simply didn't exist then.
The fact is that the rocker arms were made very narrow due to space constraints, which is why the first V6 TDI engines initially used sliding rocker arms instead of the roller rocker arms that were actually preferred from the beginning.
I cannot determine whether there is insufficient oil reaching the area, or whether the contact pressure is simply too high for the lubricating gap, which is inevitably shaped in a way that is not ideal.
In my opinion, the stiffness of the levers is irrelevant.
For continuous operation, hydrodynamic lubrication is required, which clearly did not occur in this case.
If this is not successful, wear protection additives come into play.
It is, in a way, possible that low-quality oil, such as a (mineral) 15W40 oil whose viscosity improvers have degraded and which, as a cheap oil, naturally doesn't have the best additives, could promote wear.
However, someone on the MT forum also reported having engine damage while using what was supposedly a high-quality synthetic oil.
I would never use LL with a lowered HTHS.
It would be interesting for me to know whether an oil that meets the 505.01 specification, i.e., for PD engines without Low SAPs, could benefit the NW engine, or whether the requirements of PD engines are too heavily geared towards EP (Extreme Pressure) characteristics, meaning very high pressure at relatively low shear rates, so that an oil that meets the 505.00 specification with the best possible wear protection additives, such as the Mobil 1 recommended by the "Sterndocktor," would be better.

My NW (presumably referring to a specific component or system) hasn't fully worn out yet, but it has isolated defects all around the circumference that look like pitting, similar to what you see in ball bearings. I'll be able to tell in two or three years whether this is the beginning of the end.
Pitting occurs under high, localized loads, where the greatest stresses occur BELOW the surface, leading to material fatigue, and even oil cannot prevent it in such cases.
Supposedly, the oil doesn't pass through the oil filter on its way to the heads, and that dirt is the cause. However, I haven't been able to verify the truth of this, and it's also questionable where all that dirt or debris would be coming from.

"All I can say is that my dad's 150 hp AKN engine covered 210,000 km in 3.5 years, and when I replaced the valve cover gaskets shortly before he sold the car, I didn't notice any wear on the camshafts."

The car had a full service history with 35,000 km, quattro all-wheel drive, TT5 transmission, and was only ever serviced with 0W30 Castrol oil. It also had no oil consumption.

If it hadn't been so expensive to insure back then, I would have taken it.

Okay, so I also have worn camshafts. The oil was changed three times during the first 100,000 km on my vehicle, but it wasn't long-life oil (I think it was 5W40). Then, after I bought the vehicle, I changed the oil every 30,000 km using long-life oil (0W30). Now, all the camshafts are worn evenly and quite extensively.

I believe there's an issue with the NW (presumably a component), and it shouldn't happen with the extra-hardened NW. The other parts remain the same. My problem is that there were already new versions of the NW, but the motors were apparently still being shipped with the old ones (that's what I've heard). I find it outrageous, especially since it wasn't the cheapest motor. Supposedly, the roller rocker arms in the newer generation completely eliminated this problem.

Here's another post:
/viewtopic.php?t=1975&highlight=camshafts+pictures

Best regards,
Mr. Anje.

My brother has the AKN (presumably a type of car part) in his A6 and also already has the second set of replacement parts installed.
The old ones were just built too cheaply...
I doubt that the oil is the problem, as the previous owner changed it, and the new oil has already been used for a few kilometers, but without any signs of wear.

However, you could also be unlucky and have them install cheaper parts. There was a case in the MT forum where someone had to replace the water pump twice within a short period.

I also believe that the new versions are the solution, although it shouldn't be necessary. Therefore, insist on the new versions and compare the part numbers afterwards. The numbers should be listed on the invoice. The older versions have different numbers (or letters), and now there are already new numbers again.

- Keep the numbers as they are.
- The numbers from the link listed above.
- The numbers I purchased:
059 109 021 Q (but may have already been exchanged for a B... Invoice not available).
059 109 022 BC
059 109 021 BQ
059 109 022 BD

I also believe that the new versions are the solution, although it really shouldn't be necessary. Therefore, insist on the new versions and compare part numbers later. The numbers should be on the invoice. The old versions have different numbers (or letters), and now there are already new numbers again.


Guys, here's a question about this:

I have an AFB (Abgasrückführungventil) in my A4. It started leaking at 125,000 km and was replaced by Audi with a new one (under a goodwill warranty, thank you very much for that).

I'm now approaching 300,000 km, and apart from the recently replaced fuel injection pump and the fuel pump (the fuel injection pump was probably replaced sometime within the first 100,000 km), I'm generally quite happy with the car. It drives and brakes, which is all that really matters now, although everything else is pretty much non-functional, but that's not so important anymore.

Now, I'm naturally curious about the condition of my camshafts, which are still installed. I suspect you remove the cylinder head covers and just take a look inside... (and then probably replace the gaskets), or you use one of those small inspection tools to look through a small opening.

Regardless... now there are a total of three possibilities:

'1. Excellent condition (I've always intended to use synthetic oil every 15,000 km, but I've forgotten twice, and the workshop promptly used mineral oil instead). This would likely be the case if hardened valve lifters had been installed from the beginning. It's probably less likely with an engine replaced under warranty.'

2. In a really bad state, on the verge of collapse.
3. in between.

Now, this is a component of the engine... which certainly still fulfills its purpose, but in case 2+3, it likely exhibits a certain type of DEFECT, right?

Okay, I have this unusual CarLife Plus insurance policy, and I'm thinking about contacting them and reporting the defect. I suspect that it doesn't always have to be a complete failure before you contact your insurance company.

What are the potential tolerances here? Is it easy to identify these, or is there a metrology involved that tells you whether you are still within the tolerance range?

Regards,
Felix.

"Audi specifies tolerances for camshafts of 0.5mm or more, but in my opinion, a camshaft should not exhibit even 0.1mm of wear, as this indicates poor hardening."

I've also come to believe that the camshaft problem is solely caused by faulty camshafts and is not dependent on the oil or oil pressure.

If you either add any oil that meets the VW standard every 15,000 km (or 1 year), or use longlife oil every 35,000 km (2 years) according to the maintenance indicator in the vehicle's information system, you can't really go wrong (or have gone wrong).

I've now driven 10,000 km with the new tires, and they seem to be holding up well.

Audi specifies tolerances for shafts at 0.5mm or more, however, in my opinion, a camshaft should not exhibit even 0.1mm of wear, as this indicates poor hardening.

If you either add any oil that meets the VW standard every 15,000 km (or 1 year), or use long-life oil every 35,000 km (2 years) according to the 'long-life' indicator in the vehicle's information system, you're certainly not doing anything wrong (or have not done anything wrong).

I've now driven 10,000 km with the new springs, and they seem to be in good condition.

'How much does a set of camshafts cost, and what is the cost of replacing them?'

Since I tend to consider the engine as the weakest link for now (certainly the Tiptronic as well, but that can probably be managed with regular oil changes)... and I am actually quite enthusiastic about the car's driving characteristics (I am currently driving various other vehicles and am not very impressed with them: Citroen Xsara, Golf+), I would like to drive this car for a long time , at least to reach half a million kilometers.

'For my understanding, 10,000 km is not a significant distance. I've always driven my vehicles for very long periods (Granada II, manufactured in 1979, with 340,000 km, and Granada III, manufactured in 1984, with 480,000 km), and I expect the same from a high-priced vehicle.'

Felix.

Regards,
Felix.

"Just replacing the camshafts would have cost me €1600. However, depending on the mileage, the ribbed belt, timing belt, all pulleys, water pump, and thermostat are also replaced, which brings the total cost to approximately €2500-€3000, depending on the region and workshop."

Just replacing the camshafts would have cost me €1600. However, depending on the mileage, the ribbed belt, timing belt, all pulleys, the water pump, and the thermostat are also replaced, which brings the cost up to approximately €2500 - €3000, depending on the region and workshop.

Where can I find the specifications for the services that include these additional tasks? It's certainly not included in the service plan.

My engine has just reached 160,000 kilometers, and I plan to have the 180,000 kilometer service done in approximately 10,000 kilometers.

Regards,
Felix.

At 120,000 km, the timing belt needs to be replaced. If you've already had it done, it might be enough to just replace the belt itself, without the pulleys. The water pump and thermostat are a bit of a gamble; they might last until 240,000 km, or they might not. If they fail, you'll have to take everything apart again. Usually, the water pump and thermostat are replaced at the same time, and for the price (around €70 + €25), it's probably not worth the risk of having to do it again later, unless you happen to get a faulty new thermostat, in which case you're in trouble.
If the workshop replaces the camshafts, they will tell you what other parts need to be replaced as well, because they offer a 24-month warranty on the work they do. That's why I always have it done at a VAG dealership rather than an independent garage. Make sure you are adequately protected so that you are not liable for any consequential damage from the camshafts. Have them perform an oil change immediately after the replacement, and then another oil change after 5,000 - 10,000 km (it doesn't have to be long-life oil). There is a lot of metal debris from the camshafts in the engine, and it's important to remove as much of it as possible. Read other posts on the topic of 'camshafts' or 'AFB', 'AKN'. Also, check the A4 forum at www.a4-freunde.de. I've posted all my experiences there.
Please also replace the crankcase ventilation system if you still have the original one installed.
The cylinder head covers will be replaced anyway, because the seals around the injectors are not available individually.