new car to me: 0w40 or 10w40 for Audi 2.7T?

[BryanTDI12]

Intro:
I bought a used 2004 Audi Allroad with the 2.7 twin turbo engine in January for a decent price of $3500. The body and interior were in immaculate condition and was owned by a Canadian snow bird who would drive down to Phoenix during the winter months. The car would sag every night (hence the cheaper than usual selling price) because of the air suspension so I thought I would need new air suspension but it turned out to be that the sensors needed to be calibrated because the dealer put bigger than stock tires on it I guess. I knew this would require a rather large amount of money to catch up on maintenance but It's my child hood dream car so I bought it anyways. It's all caught up now after about $2k in parts.

The main question, what oil should I run?
-I changed the valve cover seals, half-moon seals and cam tensioner seals as those were leaking when I bought it.
-New updated oil cap
-PCV looked decent
-No sludge
-Doesn't burn oil
-Car has ~157k miles
-Ran M1 0w40 for 3,000 miles to put back on 5k interval
-Switched to M1 10w40 high mileage and so far have 2,000 miles. Leak seems to remain the same pace

However, it leaks about 2-10 drops a night and I suspect it's the rear main seal. Leaks 10 drops If I do short trips, pretty much none if I do a long trip then park it.
Short of repairing the seal, should I try a different high mileage oil, continue with M1 10w40 HM, or back to M1 0w40?

I just drive the car leisurely, maybe WOT onto the freeway when the oil temp is up but I just like the smooth drive the car delivers. It's pretty much a weekend car as I use the VW for the weekdays.

 

[FCD]

10w40 sounds a bit thick for a "modern" audi, what does Audi spec?

 

[BryanTDI12]

The manual specs any Audi 502.00 spec which ranges from 5w30 to 5w40. It's hot in Phoenix and I guess I could let the car idle for a minute or two when it gets cold in Phoenix (like 40F is the lowest it will get) if it's better to run the 10w40?

 

[FCD]

I guess 10w40 will be ok in that case but just fix the leaks and forget about it and keep using a quality 5w40 from then on

 

[dparm]

I'm not crazy about 10w40 in that car. I'd stick to M1 0w40 or some other off-the-shelf 5w40/0w40.

 

[dlundblad]

Either M1 0w40 or Castrol 0w40.

The factory fill was most likely an A3/B4 0w30. The owners manual calls for either a 0w30 or 0w40 that meets the VW/ Audi spec.

A 5w30/40 Euro oil would work too (also meets their spec), but it's much harder to find than a 0w40.

 

[ARCOgraphite]

0W/5W/10W is irrelevant above 0C. More at what is the flavor of the day VAG 40 grade.

 

[Oro_O]

The HM in that weight is a good oil for this application.

M1 10w-40 HM is ACEA A3/B3, which is the same as B4 except TBN for extended drain. The HTHS is 3.9 and good for the turbo application.

I use it in my older Audi V8 and my SUV. I live where the min. temp each year is around 30F, and it's a higher mileage vehicle. After a lot of deliberation, I go with the HM instead of the 0w-40 M1 because I do not desperately need an extended drain and extreme cold starts. I prefer using fewer VIIs and the HM protection. Give it some time to work.

Did you test the PCV valve ("looks good" wasn't clear)?

 

[umungus1122]

In Phoenix Mobil 1 10w-40HM or 10w-30HM, both(A3/B3),would be better if it's leaking a bit. If it never goes below 40 degrees no need for 0/5w.

 

[BrocLuno]

I'd try Maxlife 10W-40 and see if it changes the drip... The car has enough miles that any good oil is good enough. Maxlife is a good oil. Good enough to first fill on some very expensive competition engines. Not quite VR-1, but it has more seal conditioners

 

[threeputtpar]

I owned a 2003 A6 with the 2.7t for 6 years, so I'll try to impart all that I learned.

On the oil leaks, were the cam cap plugs also changed as those are the other typical culprit for leaks on the back side of the engine along with the pass side cam chain tensioner seals. The BEL engine in the 2003-2005 models has a different designed cam plug that has a lip on it that the APB engine did not, and if you use the APB version and don't lather it up with RTV it will not seal. Also, even if the PCV looks decent it should be replaced if it's the original with 150k miles. A new one is expensive, but if you take the old one and cut out the fittings the rest of the contraption can be replaced with common 3/4 inch heater hose for cheap.

Rear main seals on these engines very rarely ever leak, thus like I stated above the leak is almost certainly coming from the rear of the cylinder head and flowing down the transmission housing and making it look like a RMS.

M1 HM 10W-40 will not hurt the engine, so no need to dump it early just to switch. Since they are both the same price at WM, just go back to M1 0W-40 or Castrol 0W-40 or whichever one is on rollback. Don't listen to those who poo poo using a 0W in a hot climate as a Euro 0W is far more stout than an ILSAC 0W anything.

If you're interested, I still have a tuned ECU from my 2.7t that bumps up hp by 50 and torque by 70 and really awakens the vehicle. It's for an A6 so it would likely set a CEL for the air suspension but would still drive and function. It takes all of 10 minutes to swap them out. $100 + shipping if interested.