I have replaced my front camshaft seal and the oil trap and my 90 740 turbo is no longer leaking from the camshaft seal. It is leaking a bit at the front of the valve cover gasket. Plan on replacing it and adding silicone. However, I am still leaking oil (although about 80% less!). It appears that it is coming from the turbo area. What are the parts that leak on the turbo? I am considering just replacing the hoses...but is there a clean out/filter/valve I am missing?

Vielen Dank!

Thanks much!

 

While the turbo motors don't have a flame trap screen like n/a cars, they can still have too much crankcase pressure causing leaks or aggravating existing ones. A simple but not flawless test is to loosen the oil fill cap and just have it resting on the vc. Rev the engine and see if it sort of "hovers"...sure sign of high crankcase pressure. Even if it doesn't, pressure could still be high. Your flame trap is a white plastic nipple, #6 in the diagram. Check to make sure it flows air and follow the small vac hose back to make sure the nipple it attaches to is clear. #1 is the oil trap which clogs less frequently than people change it. You really don't want to change out the oil trap. It has a hose on the bottom leading into the crank case, #16 in the diagram. That hose is now old and brittle...it will inevitably break off and fall down into the crank case...you don't want that. So...if you feel the oil trap is clogged w/ gunk, shoot a boat load of carb cleaner through it, then change your oil!

Old turbos will seep oil to the outside and also consume a bit of oil, pretty normal.

 

Thanks for your help as always.

I removed the oil trap and cleaned it out about 2 weeks ago and replaced the gasket for the oil cap and front camshaft seal. I am overall happy with the results as it isn't leaking 10% of what it was. I do smell burned oil in the car under acceleration and it is still leaking "around" the turbo.

Just did the oil cap test...wow, looked like magic, it was floating way up if I held it there. Just replaced oil trap w new one and checked hoses and connections... still have the floating oil cap. Where else/how else can this pressure be building up!?

Glad the camshaft seal hasn't blown again...yet.