Oil Pressure Problem AKE V6 TDI 180 HP

'Hi everyone, I've had an A6 V6 TDI Avant Quattro with a TT5 gearbox for almost 2 years. The car has always been serviced at the same VAG workshop with long-life service intervals. The last service was at 130,000 km (including the handover service when I bought it from the VAG dealer). Now it has 153,000 km on the clock. No oil consumption, I've never had to top up the oil.'

Normally, the car is not driven above 140 km/h (in Austria). However, I drove to the airport in Germany and for about an hour, I accelerated the car to around 200-220 km/h. On the way back, after about 20 minutes at a speed of 170 km/h, the oil pressure indicator came on. I reduced the speed to 140 km/h, and the indicator turned off again. As soon as I increased the speed, the indicator reappeared. I checked the oil level and added 0.75 liters. Then I drove home at 140 km/h, and the indicator didn't come on again. Shortly before the garage, at 1000 rpm, the indicator appeared again. The next day, I drove the car, and there were no indicators or anything unusual; the oil level was in the upper range.

What could that be? Is that 0W30 LL oil leaking from the engine? Or is a major engine repair looming?

I want to stop using LL oil. What oil would be best to switch to?

Am besten ist Mobil1 0W40. See: http://www.motor-talk.de/showthread.php?s=&forumid=62&threadid=230315&perpage=15&pagenumber=1
Is something long...

Perhaps during the next service (which shouldn't be too long), I can switch to the new longlife oil (5W-30) or to the "non-longlife" 5W-40.
Switching to "non-longlife" oil has already reduced oil consumption in many cases; I don't have any experience with the new 5W-30 longlife oil.

Furthermore, it might be a good idea to check the oil pressure sometime, just to make sure your pump isn't failing.

If you're experiencing oil pressure problems (e.g., like in stop-and-go traffic), I would even recommend Mobil 1 5W-50. While it doesn't have a VW approval, you can still use it without any worries for your engine. The linked thread explains, among other things, why.

Hello,

'I once had a similar issue. The oil pressure would disappear completely at high engine speeds. Eventually, it started happening even at lower speeds. The oil pump was clogged with some kind of sludge. I had been changing the oil regularly, but perhaps some 'cheap oil' had been used at some point. I replaced the pump, put in new oil, and also did an engine flush. I drained the old oil and replaced it with fresh oil, and the problem was solved.'

Best regards, Christian.

I would - instead of changing the oil at some point - measure (have measured) the oil pressure as quickly as possible. If that wasn't a false alarm, which I assume it wasn't, there is likely a problem with the oil supply. I would investigate this issue, so long as the repair remains manageable.

None of the approved oils should cause any alarms; that should be self-evident. Using a higher viscosity oil only addresses the symptom, not the underlying cause.

Change the oil (using the correct specification) and replace the oil pressure switch, as it can sometimes malfunction.

If it's not the oil filter, or if the new one is still triggering the alarm, then there's something wrong with the oil pump. If there's dirt in it, just change the oil twice, after 5000 km each time, and that should fix it.
Don't drive with the new oil pressure switch installed and a lit warning light... otherwise, the engine is likely to fail.

Good luck.

Hello mserge,

How did your camshaft damage manifest itself? Doesn't grinding down a camshaft also lead to a loss of oil pressure?


I am now driving normally in Austria with my car again (maximum 140 km/h), and there were no more alarms.

My suspicion is that the engine oil has become too thin and, given the high stress and mileage of the engine, this has now triggered the warning light.

I'm going to change the oil and possibly install a VDO oil pressure gauge to monitor the situation.

joe wrote:

1) How did your camshaft damage manifest itself? Doesn't grinding down a camshaft also lead to a loss of oil pressure? 2) I'm going to do an oil change and possibly install a VDO oil pressure gauge, and then observe the situation.

1) Rough engine running, faulty performance (mass airflow sensor and turbo pressure below target), very poor performance at low RPM. I don't understand why oil pressure would be lost. In my opinion, it has nothing to do with oil pressure at all, as there are no bearings involved.

2) This is the safest method.

"I once had the warning light come on with a relatively low oil level and old oil, when the engine was cold and I was taking a sharp turn. It went off immediately after restarting, and hasn't reappeared since I refilled the oil to above the halfway mark."

joe wrote:

How did your camshaft damage manifest itself? Doesn't grinding down a camshaft also lead to a loss of oil pressure?

No, there was no loss of oil pressure in that case, because only the camshaft lobes were worn, not the plain bearings.
I noticed the worn camshaft lobes (I saw 2 of them) through the oil filler neck. When I opened the valve covers, it became apparent that all 4 camshafts were worn.

joe wrote:

My suspicion is that the engine oil has become too thin and, given the high stress and mileage of the engine, this has now triggered the warning light.

I can hardly believe that; the oil must have been in there for more than 35,000 km and still mixed with water for it to be *that* bad.

joe wrote:

I'm going to change the oil and possibly install a VDO oil pressure gauge to monitor the situation.

Changing the oil is always a good idea, but I would still replace the pressure switch; it will be cheaper than installing an oil pressure gauge.

Hello mserge,

Okay, now I understand, it's not the camshaft bearings that are wearing in, but the camshafts themselves.
I'm going to check mine out soon. Can you see any wear and tear or any notches on them?

'What's strange about my situation is that when I was driving at 200-220 km/h for an hour, no alarm went off. The car then sat in the underground parking garage at the airport for 2 days, and when I drove out, the alarm went off after 20 minutes at 170 km/h. That's a bit odd. It seems to be related to the oil temperature, because at 140 km/h in 5th gear, the engine speed is lower than at 170 km/h, and the pump should theoretically build up less pressure. But the alarm disappeared pretty quickly after I reduced the speed.'

How many fuel injectors does the V6 engine have, and where are they located? This engine is new territory for me; I'm only familiar with the 1.9L TDI. However, that's a good thing, as I've installed a 1.9L TDI into a T3.

Hello, unfortunately, I don't know where the sensor is located. If no one else can tell you, I'll take a look.

Here's a photo of the camshaft. The lobes looked almost the same on all of them. You might not notice the problem immediately by the way the engine runs, and you can technically drive the engine until the lobes wear down by a few millimeters. However, if there's damage, it can completely ruin the engine because of the metal debris, which acts like sandpaper.
It can also happen that the levers break, and then you'll get the same result.
If you're riding with waves that are already breaking (and also experiencing an oil warning light that comes on intermittently), it's like playing Russian roulette .

I found the oil pressure sensor; it's located on the oil line leading to the turbo. Next to it is the oil temperature sensor. Unfortunately, there's so little space that there's no room for an oil pressure sensor for a gauge. I also checked the camshafts through the oil filler neck, but I only saw bare, clean surfaces.

What is Audi's policy regarding this? Camshafts should normally last the entire lifespan of a vehicle.

joe wrote:

What is Audi's policy regarding goodwill in this case? Camshafts should normally last the entire lifespan of a vehicle.

I believe it's up to 4 years and 150,000 km. I'm already past that point. A car's lifespan is definitely a factor, and Audi/VW probably considers the above figures to represent a typical car's lifespan.

"Mine was a little over 5 years old and had 130,000 km on the clock last year. After a lot of (and I mean a lot) persuasion, I got a 50% discount on the parts, which saved me about 600€. Not much, but it's something."