Just got my son a new car and decided to rebuild my wifes old 740. We have a B230F engine. I have replaced the flame trap and valve cover gaskets,cam seals,front and rear. I still get a drip of oil on the floor,( driving me nuts.) I suspected a bad rear main seal, because my flame trap and oil trap was really clogged. Finally got a bright lite under there and found out where the oil is coming from. On the engine block, behind the exhaust manifold I found a " plug " type attachment sticking out from the block. It is all the way to the rear of the block ( under # 4 cylinder ) halfway down the side of the block. It is a screw in type fitting with a hollow end on it. It appears a hose, or some sort of fitting should fit over the end of this. This is where all the grunge is coming from, and from what I can see, has been coming from for quite some time now. Oil just seeps out and drips down the block and around the area where the auto trans bolts into the engine, giving the appearance that the rear main seal is leaking.

What is this fitting for ? I can't find anything that goes to it, there are no " extra " parts hanging around or disconnected hose's. To give anyone a better idea what it looks like. First off it definately screws into the block and the end sticking out looks almost like the end of the fitting on a compressed air fitting. My Hayes manual has no mention of this and not picture of it. This car is fuel injected non turbo.

Richie

I'm making an assumption that this fitting is actually on the rear right hand side or Pass. side? If that is correct then it is the coolant drain fitting and is not likely to drip oil. You can check this easily by looking in the coolant reservoir, oil is lighter than water. For oil to leak from the drain fitting you would have to have a cooling system that is totally full of oil. I suspect the oil leak emanates from the rear mounted distributor as I believe all B230's have cam driven distributors. The orings are simple to replace but the internal seal is a real bear that requires disassembly of the dist. I would degrease the engine completely (you may have jack it up to really thoroughly clean it)and recheck the valve cover, head gasket is also a remote possibilty.

Tom Kaylor

Senior Service Engineer / Clevite Engine Parts

Tom

Thanks for the info. Can you please tell me how to seal the coolant drain plug up ? Pleas let me know

Richie 87 740 gle

Richie,

It sounds like you are describing the drain plug on the block. Drain plug for the cooling system that is. Does it have a hex fitting on it that is 13 mm? You should not be leaking oil out of there, perhaps it is antifreeze? It does look somewhat like an air fitting in that it is made to have a hose pushed onto it to drain the coolant.

Randy

Randy great !!! now what attaches to the drain plug and where does it go to when I attach it

Richie 87 740 gle

Under operating conditions NOTHING attaches to it. It is used to drain the coolant. A hose of about 1/2" diameter will direct the draining coolant into a container under the car. If it is dripping COOLANT than simply use a 13mm wrench to tighten it to make it stop. Most likely it isn't leaking oil or coolant as you would experience an overheating condition before long. It may appear that your oil leak is coming from there but more than likely the oil is leaking from the distributor at the back of the head/cam cover.

Randy