Never a truer word said!

 

Oil pressure caused by a boost leak? hmmm Am I missing something here?

No boost after they fixed the boost leak - they should check for boost leak again.

I know my oil sensor is acting up sometimes, it throws me a warning (Sensor) but goes back up, usually on bumpy streets.

Do not drive your car, I agree, you do not want to mess with low oil pressure, btw that's a lot of labor hours. IF you decide to drop the motor, pin the coolant lines

Take your car somewhere else, get second opinion. Good luck.

 

I own a shop, first thing is t find and resolve the idle dip, If your car rolled i. I would first rule out all vacume leaks. Including facility bypass valves. Next I would make sure car has good plugs, and clean examine throttle body for iac. If rpm is low enough with engine running and key on, oil pressure warning could active because motor is not spinning am fast enough to keep oil pressure up. After the idle is fixed, I would hook up an oil pressure gauge to test actual pressure only if your pressure gauge in dash shows very low oil pressure and warning activates.

 

First of all, how can they know one turbo is overheating? Sounds fishy... also, does the rpm and/or oil pressure dip when you depress the clutch while idling? This is very important info and indicative of bigger issues. Try it, let us know.

 

Drain both turbo sumps, if one has hardly any oil then you have an issue, the 'overheating' turbo should have less oil come out the sump.

 

I like the theory but without a thermocouple to provide temp data from both sides, I feel this is a "it looks different so must be hot". A journal bearing turbo with low oil pressure will die very very quickly.

 

Infrared heat gun will tell you exhaust temps very quickly, we use ours every day to pin point weak cylinders, but I think I would be going for a proper oil flush and filter change as well as sender change and fill with a more suitable weight oil than a 0/40.

 

I would take the car to a qualified shop with a good rep on the back of a flatbed.

 

^ only to add that if the shop you've been using has not or doesn't have the time to fully diagnose the issue further? again, it might be a good idea still to get a second opinion.. are you reluctant to mention which los angeles area shop you are currently using? i only ask as there are many here that might be able to refer you somewhere else local where you might possibly be better served and get this sorted more quickly. at the very least, it's something to consider.

 

You have received some good counsel. Let me add my two cents' worth...

First in the case of a suspected oil pressure problem unless one believes he is capable of trouble-shooting this one should seek out a qualified shop for further investigation.

*Real* low oil pressure is nothing to mess around with.

As others have offered and I have to agree, your "trusted shop" leaves something to be desired based on what you have posted how it has handled the car so far.

You really should ask for recommendations to shops in your area unless you are prepared to find a suitable one on your own.

Next I doubt -- but I am not a professional auto tech -- there is a real oil pressure problem. The idle problem I think "causes" the oil pressure problem, symptom at any rate. The engine has a minimum idle speed -- 740 +/- 40 RPMs IIRC -- and if RPMs drop too far below the minimum, while the engine may still run oil pressure will fall. Gear oil pumps are not very efficient at lower speeds.

At hot idle the oil pressure may -- this is based on observing using the dash's oil pressure gage, which is to oil pressure measuring like a finger nail file is to a surgeon's scalpel -- may read just "1" bar or around 14psi. I do not know at what pressure the low oil pressure warning is triggered but I doubt it is much below 1 bar.

The factory manual which is my reference only supplies an oil pressure specification with the engine up to temperature and at some high RPM. IIRC oil pressure should be approx. 6.5 bar at 5K and with the oil at 90C.

As an aside, this is with the factory fill oil. I do want to get off track here and on some oil discussion but unless you have 5w-30 oil or something equally off the recommended viscosity chart, in the engine, or the oil has like a bazillion miles on it and is so diluted it looks like weak tea, the oil is not the problem. After you get this low oil pressure/idle thing addressed if you want to discuss oil that's a discussion for another time.

It is my opinion that barring clear signs of an oil pressure problem the most pressing problem is the idle issue. My opinion is fix this and the oil pressure symptom goes away. That is unless you see, or a tech sees, a steady idle or the engine is held at some higher but steady RPM and the low oil pressure warning light comes on, or doesn't, but in either case, with the tech observing the actual oil pressure with a trusted oil pressure gage connected to the engine and actually measuring the oil pressure and sees oil pressure that in his professional opinion clearly points to an actual oil pressure problem.

What else? Oh the "hot" turbo. As others have wisely asked how was this determined? Unless the sucker is glowing red while the other is dark or the temperature was checked using a temperature probe -- we used one for checking the temperature of welded fabrications during welding to ensure proper pre-heating years ago in another career -- though nowadays infrared temp probes are quite common and any shop worthy of the name - and any DIYer for that matter -- should have one in his tool box -- I question this diagnosis.

If the turbo is running hot, truly hot, there are a number of explanations for this, and on the list but down the list is oil pressure. IIRC the turbos have their own oil pump and I know the oil is supplied to the turbos via metal oil lines and is carried away via other metal oil lines. A crimped/pinched or a corroded line or some interference with oil flow at any point in a turbo's oil supply circuit can affect oil supply/pressure to the turbo.

Of course when you find another shop you will mention this hot turbo "diagnosis" and let the shop prioritize what it does and in what order.

 

^ nice.

 

Thank you for the responses everyone! Much appreciated. I will definitely get a second opinion as it seems like there are a number of questions that still need to be answered.

I have had one person PM me recommending HD Motorwerks in Glendale.

Please let me know if you have any shop recommendations in the Los Angeles area. I wont mention the name of the place the car is currently at but they are an independent Porsche / Audi shop.

Again, thank you everyone for your suggestions.

Justin

 

pm sent. you should give them a call. good luck.

 

Good Luck!!!

Please keep us up to date with your progress and final diagnosis.

 

I had the exact same issue.
Shop told me it was internal issue and will cost $30k to rebuild engine.
They apparently did a manual oil pressure test.
I just replaced my voltage regulator and my oil pressure sender and my oil pressure is now back to normal.