Kevin Beardsley

The Story and the Question for consideration please.

Car: AUDI A6 2006 (C6) 2.0T FSI Petrol - Manual

• FSH (Done by ex Audi Technician for last 3 yrs after dealership, who runs a very successful servicing business of his own now)
• 120,000 miles of 'very steady' style driving.

Facts:
The Engine runs/pulls smoothly and sweetly at any revs.
Not that I get higher than 2000 revs before changing up a gear.
All Timing Belts and Chains (in fact all engine consumables) changed as per Audi schedule or better at Servicing.

Story so far:
18 mths ago the OIL pressure [warning light/alarm] started to activate.
The OIL pressure warning doesn't activate until the A6 has been driven for about 20mins (ie engine has warmed up)
But even then - ONLY - when the car comes to a stop/halt at lights and junctions.
It's so predictable that I can now second guess it, 2 seconds before it comes on.
As soon as you start moving again - the warning goes off - and NEVER comes on again - until the car comes to a stop/halt again.

Actions so far:

1. New Oil Pump
2. Scounger pipe and filter checked and cleaned (wasn't dirty anyway)
3. Engine Main Bearings changed
4. Sensor checked (all good)

Result:
After 10,000 miles of driving with the issue over the last 18 mths.
The Audi has never performed anything less than 100% reliably over the period.

Hopefully, There are a few Sherlock Holmes' and Engineers amongst AudiWorld who can explain the mystery?

I look forward to engaging

Kevin

Sam Zubel

Ive seen this problem 100% like you. Every part changed like you, and also the PCV on the valve cover. I never got to find out what happened though. Two things id suggest from doing lots of research on this and going by the car i described that had changed everything but this part. The MAIN pcv valve apparently is the Black box thing on the front of the engine, the one on top is a secondary in a way, well for you right side, under the intake. The drivers side engine mount bracket is right next to it. I would research what ive described and youll see what i mean.
Also, in the cylinder head on the chain side, there is a brass spring loaded check valve that can only be changed with the cylinder head removed, but it just pops out, ive seen those valves internals missing on some heads removed from engines. But i believe that to be so oil does not drain out the head overnight and leave it empty on a cold start.

Check out the block breather on the lower part of the engine and reply with your thoughts. Read the audi SSP for crankcase ventilation and itll explain it all

Kevin Beardsley

Thanks Sam
A new avenue to check, to locate the cause. Hopefully.
After 3 weeks since the post.
I'm slightly surprised that more 'SPECIALISTS' from Audi haven't commented.
The Audi Illuminate are quiet.
How much would an Audi dealership charge to explore and solve ?? ŁŁŁ

Kevin Beardsley

Thank you Sam
I've suggested your thoughts to my mechanic.
Fingers crossed
Regards
Kevin

Sam Zubel

I’m not surprised on the lack of opinions. This is a “scary” topic for most on these newer engines where it’s not like it used to be. Now these engines have a laundry list of items that look at, control, affect and be effected by the slightest change. This is a perfect example. Only when initially leaving a stop after having just come to a stop after 20 or so minutes of driving, when pressure is changing say from high to low and back to high in the smallest amount and have it trigger a light, even after the real major components are new. Makes you really go wtf.

As far as a dealer trying to diagnose this. First I’d like to know how, but can see large money in diag time, then if it was an engine where these parts haven’t been changed, sell you on those and still have the same problem.

I really think it will come down to a crankcase pressure problem, where there’s excess which ever way you try to see it when stopping then going and it has to be moved or equalized as the oil pressure is doing its thing, and ecu reading the change “window” from the 2 pressure sensors and its id say “delayed” from the internal pressure not moving how and where it should just fast/enough for the ecu to see a hiccup and trigger the light/tone. By the time the tone comes on crankcase pressure is solved and it goes out.

Thats my hypothesis atleast. So really looking forward to seeing this outcome if you change the lower block breather/pcv

Kevin Beardsley

Thank you again Sam
I'll update you and the thread, once your suggestions have been added and checked in the 'Laundry list' of possibles
All the best
Kevin

Sam Zubel

I was just thinking , since you’r across the pond, and model years and engine vary compared to the ones in the usa. You say c6 with a 2.0t. C7 here has the 2.0t timing chain motor. You also mention “timing belts and chains” and fsi. Am I discussing a differ t engine than you have? I’m not aware of the c6 being offered with a 2.0t fsi.. just noticing this now. So you have the fsi 2.0t that is a timing belt motor correct? And the little “timing chain” just for the cams. Maybe provide the engine code if you could/ have that present, or a picture of the engine compartment.

Kevin Beardsley

Type : 4F2.08C
A6 Lim 2.0 R4
125Kw M6S
Engine code: BPJ
Trans.code: GVC

Regards
Kevin

Sam Zubel

Hmmm no shiet. C6 A6 came with a fsi engine. So first. What I described was more or less for a ccta/cbfa 2.0tsi chain engine. And said oil issue was for that engine aswell.

To keep it short and sweet. For the fsi engine. The oil filter housing has a built in pcv assembly. You’ll find a breather hose running from it up to the pcv on the valve cover.

I would replace the oil filter housing as its plastic and has an internal venting system in it.

The pcv on the valve cover, use a oem one per vin # as I’ve heard one time someone either used a cheapo one or different engine code that cause a lean code.

And also the valve cover itself has a baffling assembly inside that the external pcv screws to. That if gunked up, will affect the flow from the oil filter housing, to upper external pcv on the valve cover, to finally flow in/through the actual valve cover internal workings.

Side note, can’t confirm but I heard from the grape vine, the oil filler cap has a thing inside, almost like the coolant bottle cap release valve sorta thing.

So in turn, id deffenitly throw on a new oil filter housing, pcv “pancake” valve on the valve cover. See where that gets you. And last the valve cover itself as all of it over time gets built up with the crankcase vapor sludge.

Kevin Beardsley

Hi Sam

Whilst evaluating the remaining Laundry List of possible causes.

I have to ask the $1000 question.

If the Audi remains reliable and the cause can't be isolated and solved.

Is it possible to 'defeat' the sensor to prevent the endless distracting alarms ??

Peace and Quiet would be a luxury !

Regards
Kevin