Oil in Intake how much is normal?

[perryg114]

I have a 91 GS turbo that I am in the process of fixing up. One of the things I am doing is rebuilding the turbo. It has for most of its life leaked a lot of oil into the intake. There is always a good bit in the intake and it also seeps through the rubber hose joints and runs out. How much of this oil leakage is normal. The seals are just a piston ring around the shaft so I can't imagine that being an oil tight seal. I bought the car new and it has 120,000 miles on it. Nothing, engine wise, has been replaced accept the belts and the water pump since it was new. Oh yeah, I did crack a manifold and replaced that. The turbo has no end play but there is some side to side play.

Perry

[Pushit2.0]

I would look at your crank case breather line(from valve cover to intake pipe) and PCV valve. Normaly that is where oil comes from.

~John

[perryg114]

Thanks I will look at that. So do I need to be messing with the turbo bearings? Is noticeable side to side play in the turbo a bad sign?

[Pushit2.0]

Some side to side is ok, in/out is what is realy bad. A new turbo or a good used turbo might be in order.

~John

[perryg114]

Why would I need a new turbo unless you are trying to sell me one? A used turbo would most likely be in worse shape than the one I have that has been taken care of. Anything can be fixed it is just a matter of how much stuff that will have to be replaced. I already have the bearing kit. Worst case would be a new turbine and shaft.

Perry

[dragonforce]

When you rebuild the turbo, everything has to be balanced inside. It is more complicated than you think.

[perryg114]

Well I am planning to mark everything so I can put it back the way it was. Like I said, other than the oil in the intake the turbo and car runs fine. If it was seized up I would definately have it rebalanced. If there is any contact with the scrolls or missing blade parts or lot of erosion I will definately have it rebalanced and parts replaced as necessary. Its got 120,000 miles on it. Its all stock and I run synthetic oil in it so I hope it is not coked real bad.

Perry

[niterydr]

Well I am planning to mark everything so I can put it back the way it was. Like I said, other than the oil in the intake the turbo and car runs fine. If it was seized up I would definately have it rebalanced. If there is any contact with the scrolls or missing blade parts or lot of erosion I will definately have it rebalanced and parts replaced as necessary. Its got 120,000 miles on it. Its all stock and I run synthetic oil in it so I hope it is not coked real bad.

Perry

What do you plan on "marking it" with?

You do realize that turbochargers spin at 100K+rpm and any slight imbalance/imperfection/mis-adjustment will send it apart quickly.
The average shelf life on an OEM turbocharger is 100-150k miles. After that bearings and seals usually need replacement. I would suggest to find a low mileage 14b, a new turbo, or send it to someone that does quality, reputable rebuilds.

On a side note, John was not trying to sell you a turbocharger. If he would have posted "Buy an Evo 16g from us for $569.00 plus tax", THAT would have been trying to sell you a turbo. He was mearly providing information and an answer to your question.

In and out movement (on a journal bearing turbo) indicates thrust bearing wear. Slight side to side wear is normal. The amount of oil inside the center section can really effect how much "load" is felt.
If your crank case system is in check, you might have to look at the turbo for possible signs of seal failure. Are you still running the valve cover breather into the intake?

[slowbubblecar]

Diesel Components in Burnsville could rebuild and balance it for you if you are set on keeping your old turbo and rebuilding

[perryg114]

What do you plan on "marking it" with?

I am not sure but I know it can be done because anyone that balances these things has to take the shaft off and balance the assembly out of the center section. It them must be taken apart and put back into the center section. If you have any suggestions as to how to do this I would be grateful.

You do realize that turbochargers spin at 100K+rpm and any slight imbalance/imperfection/miss-adjustment will send it apart quickly.

Yes I am an aerospace engineer I am familiar with turbo-machinery. I am assuming that if I can keep the turbine and the compressor properly clocked that I can maintain the factory balance.


The average shelf life on an OEM turbocharger is 100-150k miles. After that bearings and seals usually need replacement. I would suggest to find a low mileage 14b, a new turbo, or send it to someone that does quality, reputable rebuilds.

Finding the latter is hard to do.

On a side note, John was not trying to sell you a turbocharger. If he would have posted "Buy an Evo 16g from us for $569.00 plus tax", THAT would have been trying to sell you a turbo. He was mearly providing information and an answer to your question.

Sorry, I am pretty good with mechanical things I earn a living at it. I am not a turbo-charger expert but I am pretty competent with most things.

In and out movement (on a journal bearing turbo) indicates thrust bearing wear. Slight side to side wear is normal. The amount of oil inside the center section can really effect how much "load" is felt.
If your crank case system is in check, you might have to look at the turbo for possible signs of seal failure. Are you still running the valve cover breather into the intake?

Yes everything is stock should I change something to reduce oil consumption?

The turbo has a good bit of side to side play on the compressor side but very little axial play (in and out) and very little play on the turbine side. The turbine and compressor are in good shape and nothing was hitting the scrolls. The turbine does not look eroded at all. I am a little concerned about there being more play on the compressor side than the turbine side that has a much harder life.



Perry