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Discussion Starter · #1 ·
Lads, first things first: although I've been searching through iPhone, I don't have a computer with me right now, so my quest for answers could have missed something. My apologies I that's the case.
However, it seems as all the oil-related posts are due to excessive consumption, which is not the case.

I serviced my 2.0 TFSI last August 10th, with proper oil filter replacement and oil change, using Mobil 1 with the right specs.
Now the problem: this August 19th, just few hundreds of miles ran, I had "low oil level" warning on the dash info. I've put half litre without checking the level at the dipstick, started the engine and after half-mile came the warning again. Finally checked the dipstick and oil was top filled (perhaps a little above max... So dumb I am). Today I visited my mechanic and we're both trying to figure what's wrong, but no clue...
Just to mention that, prior to the first warning, I drove tough, very fast and extreme, but nothing I hadn't done before.
I believe (I'm not certain) I heard valves hammering at some point, but not anymore.
One more info: once I start the engine, no warning comes up, but a few steps on gas are enough to prompt the warning.

A friend told me that some Audi TDI need to replace an axis inside oil pump when this happens.

We're now going to insert original Audi oil filter and check oil pressure.

In the meanwhile, can somebody give me a precious help, or even if have had same problem?

Thank you all!
 

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2001 Amulet Red 225 coupe.Owned from new as well as a Nurburg VXR & an XR3, all from new.
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Hi, Assuming you checked level 5 minutes after engine off & level is still correct on dipstick & It was oil level low & not oil pressure low. If oil level is correct, then I would think level sensor is playing up.
Oil pump prob would not be related to oil level, but it would be to oil pressure.
Hoggy. :D
 

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Discussion Starter · #3 ·
Thank you, Hoggy, always so helpful!

Your thinking is logic and correct; however, it seems as this fault is being all but logic.

After testing and measuring oil pressure, the results were within normal parameters. Changed oil, oil filter (Audi original) and pressure sensor and still the same problem.

As I told you before that I had the slight impression that the valves were "hammering" at certain time, I decided to be a little harder while testing and so they came to hammer again. It's a heartbreaking sound, it really looks like there's a mechanical slaughter inside the engine.

So I've heard that some Audi's (TDI or petrol) have a common problem with oil pump's axis or valve. Is it possible that mine can't handle the heat? Or could it be a faulty whole oil pump?

Right now I'm at the mechanic we're trying to solve... please help
 

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Are we talking low oil level warning or low oil pressure warning?

The low level signal is a false warning, given the level is actually correct. But if you're hearing strange noises too (and these aren't the injectors) then there might be a real oil pressure problem.
 

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Discussion Starter · #5 ·
After I've done a rough test-run and heard valves hammering, we measured oil pressure again (at intensive engine heat). Very low pressure at first test, no pressure at all in two following tests. Now I know the level warning was indeed false.

Now what: new oil pump? Or could it be that this pump has a problematic axle as reported in the TDI's?

And just in case.... how much does the oil pump cost?

Thank you all, again
 

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OK, I see. A German owner experienced the same problem: issues after driving fast. He actually ruined his engine completely. After taking it apart, he discovered that the oil filter (not the one that you've replaced, but the one in the sump that is the entrance of the oil pump) was completely blocked with black sludge.

So: time to let the oil out and either check with an endoscope that filter, or screw off the sump and check it.

Having dinner first now. I'll be back soon!
 

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Discussion Starter · #7 ·
Indeed, I'm affraid my engine is being ruined since the issue showed up and following testing...
I'm removing the sump/pan right now and I'll look for that filter and be right back with results.
We already used the endoscope and found nothing worth worry - at least, said the mechanic.

Thank you again ;)
 

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Discussion Starter · #9 ·
Thank you for your prompt attention...

Oil pan/sump removed and really there was a huge amount of black sludge in that inside filter, added to metal debris.
We're suspecting it's source (can't really tell you right now because I'm unable to translate the parts name), but we're disassembling a little more to be certain.

At least we (most probably) found the cause, thanks to your help.

I'll keep you posted with news as soon as I get them, I promise.

Words can't describe my appreciation towards your concern, care and help.
 

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You're welcome and I'm glad I could help. I sincerely hope that the amount of damage in the engine isn't too bad.

The fresh oil (with fresh cleaning additives) and high temperatures will have loosened up black sludge, which then was sucked up into that filter.

I'm curious as to what the history of the car is. How many miles/kilometres has it done? What oil was used? When did it have it's services? Many short trips, mixed of mostly long trips?

Some pictures would be great too.
 

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I presume the "valve hammering" is a collapse of your cam followers due to low head oil pressure - possibly due to a clearance opening up when hot - possibly due to a blockage.

A common one on the Mk1 engine is the hydraulic cam chain tensioner which trends to play up at idle when the oil is hot. Oil pressure measured at the pump may seem OK. At higher revs the noise goes away as the leak is only significant at low volume oil flow. I'm not familiar with your engine but it may be similar.

Other possibilities could include a large piece of debris blocking the oil strainer at high flow - possibly sludge. The oil pump leaking when hot (I once had a Vauxhall with a loose oil pump backing plate) - could be loose mounting or leaking seal when hot.

Does the cam follower noise happen at idle or at high revs when hot? This is key.

Another useful diagnostic is to measure both the oil pressure at the pump and also at the head (if you can find a blanking plug - or possibly at turbo union), as you'll be able to see if it's just the head pressure dropping or the whole engine.
 

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Having so much black sludge in the sump means you'll have to take the valve cover off too. Gives an opportunity to see what state the camshafts are in as well as cleaning all junk out.

I'm not entirely sure how to take it from there. Cleaning and flushing is one thing, but what's all to check before actually starting up the engine again...?

If there is no wear and tear on the camshafts and no obvious resistance when turning around the engine by hand and no visible damage to the oil pump, would it be OK to start it up again once all is put back onto the engine?
 

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Didn't see the results of your investigation when I posted. It may be worth taking off some main and big end caps to see if there's any damage. Use new bolts on reassembly. I hope it's not too extensive and the crank is Ok.
 

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Discussion Starter · #14 ·
Again, I'm very thankful for your attention, you all.
I'll check on the valves for sludge soon...
Meanwhile, our biggest suspicion on the splinters/debris found in the oil pan is on the rod bearings, due to its colour. However, my mechanic called a guy who's supposed to be a specialist in VAG engines to say what's the next step, let's see and I'll keep you reported with news.

One more fear I have: could it be something wrong with the chain that commands the oil pump? I say this because the worst symptoms are shown with extreme driving and greatest engine heat, when the oil is supposed to be thinner but it's when doesn't reach the valves' head, thus its hammering sound... The chain seems properly tense, but is it possible that, in extreme driving & heat, somehow it looses?
 

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Thinner oil gets pushed out easier, especially when supply is low. Plus when supply is low, due to that blocked filter, the oil pump can build up less pressure. On top of that, 5W30 combined with 40 degrees C outside and driving hard perhaps leads to oil that is actually too thin to maintain oil pressure. This is why some track day cars are filled with 10w60 'racing oil', just to maintain oil pressure under high load/high temperature situations.

Before getting anywhere near starting up the engine again, do check that the turbo still receives enough oil. The pipe should be free of contamination.
 

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As per John-H's post I'd also guess that the 'valve hammering' noise is from the cam followers and I'd suggest that it was due to low oil flow to them caused by partial blockage of the oil pick-up strainer in the sump.

If the oil pump drive chain is correctly tensioned when cold then I doubt that expansion due to heat will change that by an amount significant enough to affect drive to the pump.

If you have clear evidence of bearing material or bearing backing material in the sump then again as per John-H's post you need to check all the big end and main bearings for damage along with the crankshaft journals.
 

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Discussion Starter · #19 ·
Well, we're not sure yet the debris/splinters come from the bearings, we'll find out as soon as we sort out the best way to open it (once the car is on an elevator and the engine is opened from the bottom, we're not sure to continue disassembling from bottom or top to check bearing rods.
John, the damned noise came from the top of the engine (looks as coming from valves) and raised with rotation, actually sounding like hammers. I'm most thankful for those brochures on bearing shells, I will check if the shells match any of those conditions - in case (says the mechanic) we find them loosen or damaged. In such case, I'll remove everything and check the crankshaft and the rods, pursuing any visible or suspect damage.
 

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jalms said:
You refer to the pipe that leads from oil pump to turbo? I've been using 5w30 Mobil 1, VW504/507 specs, at a range of 20 to 35 Celsius outside...
Yes that's the pipe I'm referring to. It would be a shame if by ignoring that pipe the turbo would die due to lack of oil once all the rest is OK again.

You've used the correct oil and 20 to 35 degrees should IMHO fall under normal operating temperatures.
 
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