TD Vanagon, Tap oil pan or block?

myke_w · Post by **myke_w** » Thu Feb 16, 2006 5:17 pm

I have been thinking about the oil return problem with the aluminum pan for a while. Couldn't one tap the back of the block and have a bung threaded in that way? It's done in the tdi, so why not TD right? Does anyone have any insight on this? What would be the obstacles?

libbybapa · Post by **libbybapa** » Thu Feb 16, 2006 5:23 pm

EDIT 2/17/06: The flipped quantum manifold will not work as there is a severe interference between the wastegate and intake manifold.

The largest obstacle is the elevation of the turbo and return line. The drain is gravity flow only. It must run downhill all the way to the pan with no uphill runs at all. Otherwise oil can back up to the turbo and cause a slew of problems (runaway, oil out the exhaust, blown turbo bearings, blown turbo seals, coked up turbo, etc...) If you used the flipped quantum manifold I am fairly certain that you would have enough elevation to run downhill to the block. With the quantum manifold in the normal orientation I am quite sure you wouldn't. I'm not sure with regard to the jetta manifold.

Andrew

myke_w · Post by **myke_w** » Thu Feb 16, 2006 11:59 pm

I am planning to go quantum flipped
Ok, now where to go through the block? high? low? closer to 1 or 4? Whats the smallest fitting I can get away with and still have good flow?

libbybapa · Post by **libbybapa** » Fri Feb 17, 2006 12:36 am

I wouldn't go any smaller than 3/8" ID on anything on the return line. 1/2" ID would be better.

Andrew

myke_w · Post by **myke_w** » Sat Feb 18, 2006 10:12 am

on a side note... any clue where the original vanagon td oil return port was located in the pan? anybody have a pic of that setup?

myke_w · Post by **myke_w** » Sat Feb 18, 2006 10:19 am

An etka pic of the turbo setup on vanagon td...
where does this place the return?

libbybapa · Post by **libbybapa** » Sat Feb 18, 2006 10:26 am

The TD vanagon uses a different oil pan than the non-turbo. There is a boss in it toward the flywheel on the driver's side.

Andrew

myke_w · Post by **myke_w** » Sat Feb 18, 2006 10:39 am

hmm, that almost looks like an uphill run... Would those of us thinking of tapping the pan want to try to retain the original return location or try a different spot?

libbybapa · Post by **libbybapa** » Sat Feb 18, 2006 11:38 am

The uphill run is an optical illusion due to difficulty getting the camera under the van for a decent photo. It is downhill the whole way. I would put the return where it is convenient.

Here is the same picture witht he camera angle corrected.

Andrew

libbybapa · Post by **libbybapa** » Sat Feb 18, 2006 11:41 am

myke_w · Post by **myke_w** » Sat Feb 18, 2006 11:42 am

LOL
cool photochop.. I gotcha now..

stopping · Post by **stopping** » Fri Feb 24, 2006 11:47 am

Hey Andrew,

Just back from up north. Thanks again for all your insight. (esp regarding oil levels in the Vanagon AAZ with gaser tranny) I am not down on my engine, I think the aaz is the best solution for these vans...... I don't have a garage and I live in the city so working on the vehicle in the Montreal winter is less exciting then it could be.

I want to ask about this oil return line. I have an AAZ engine with the oil return in the block and it runs uphill with the AAZ at the 50 deg. angle for the van. Guess I should check for "coking" and bearing play and try to resolve this the way you did.

Questions:

Is it pressure in the oil pan that keeps the oil from draining even up hill?

What it the difference in pressure between the amibent air in the oil pan vs. the "allowable" pressure on the turbo seals?

How much oil are we talking about here? A jet or a trickle?

btw thanks also for that ecellent tranny/ gear calculator link and the great invention on the "bottle jack break"

Steve

libbybapa · Post by **libbybapa** » Fri Feb 24, 2006 3:50 pm

The bearings of the turbo are pressure fed. The drain is purely from gravity. The oil flow will be largely rpm dependant (oil pressure dependant really), but I imagine that sometimes more oil moves when the turbo is spinning faster. The oil return line is purely gravity flow. The turbo should be indexed so that the inlet is at 12:00 and the drain is at 6:00. Also the return line should run downhill the entire way from the trubo to the block/pan. If you have any section that runs uphill, I believe that the pee trap along with the viscosity of the oil will cause it to back up into the turbo in high-flow situations. If that happens it will flow out the shaft seals. The seals are not oil tight. They are basically piston ring types and rely largely on oil slinging away from them. If oil backs up into the turbo it will blow out the turbo seals. There should not be any appreciable pressure air pressure in the oil pan and is not really a factor.

Andrew

Former VWDieselParts.com Forum

TD Vanagon, Tap oil pan or block?

TD Vanagon, Tap oil pan or block?

Turbo oil return