Dipstick oil leak

[maineSS]

Well, it seems my oil leaks weren't entirely solved by replacing the oil filter lines (I did both, just to be sure). The oil doesn't come out at idle or at 2000 rpm when the truck is stationary, but going down the road seems to cause a leak around the dipstick. I originally suspected the distributor, but both the inside and outside stayed dry after I cleaned the block for my latest test. There is some crankcase pressure due to worn rings, but not enough to pop the dipstick up either during stationary or road operation.

Did these dipsticks ever have a seal for the slotted cap? Mine slides up & down freely on the dual "spring" at the top with light hand pressure. I'm thinking about cleaning the dipstick at the top and siliconing the slot shut on the cap....

[Gordon Maney]

What engine are you working on?

[maineSS]

Here's what the B1 230 dipstick looks like at the top (pic #1). The slotted disk rides on the double "spring" part of the dipstick, and sits atop a hole in the side of the engine block. Not very much resistance to oil splash, especially if it's aided by crankcase pressure. I think the added surge of road movement allows oil to slop up into the block hole, where it gets blown out thru the slot.

I cleaned off the top area of the dipstick with paper towl and Brake Cleaner, and then carefully packed Silicone gasket maker into the slot, top, and bottom of the disk (pics #2 & 3). My next test trip showed some leakage around the disk where it contacts the block, but no upward movement of the dipstick. The best fix would be rebuilding the 230, and replacing the slotted cap on the dipstick with one that seals both the stick and around the hole with an O-ring. Did Dodge ever make a better dipstick for the 230?

[Gordon Maney]

My concern is that you have sufficient crankcase pressure to cause oil mist to be forced out. This should not occur under normal circumstances.

I am interested in some other opinions.

[MoparFreak69]

My concern is that you have sufficient crankcase pressure to cause oil mist to be forced out. This should not occur under normal circumstances.

I am interested in some other opinions.

I agree with Gordon's point here. There really should be no reason that oil is being forced up the dipstick tube if everything is in proper working order. Sure there will be splashing that occurs, but nothing that would force fluid very far up the tube. Is your breather/draft tube clean and clear? Do you feel any air blowing out of the dipstick tube with the engine running? You would probably have to disable the fan to check on it, but it may be worth the half hour or so of time to remove the fan and check to see. Air should not be blowing out of the tube under any circumstance. Air blowing out indicates either a plugged breather/draft tube or so much blowby (caused by worn rings/scratched cylinders) that the breather cant expell the air fast enough and you are creating pressure in the crankcase.

The 4 cylinder in my Jeep when I got it was a leaker no matter what I did to it. It did the same as you described, wouldnt leak at idle or revving, would only puke oil when driven. Turned out that the fan was forcing the oil that leaked out of the front main back and splashing it all over the dipstick tube and the oil filter adapter making it look like that is where the leak was coming from.
Basically my point is; are you absolutely sure this is where your oil leak is coming from? Do you see any signs of oil splashing off of anything else making it look like the leak was coming from the tube? Just trying to give some more ideas, points of views, places to look.

[Cheyenne Dave]

If we are talking about the 230 engine in the B-1 Power Wagon, I have two observations...

The dipstick pictured seems not to be correct, or at least is missing the umbrella cap that slips over the top of the dipstick tube.


You could find that the dipstick tube is either cracked or ill-fitting where it swedges into the block. An oil leak at the base of that tube could happen without high crankcase preasure.

C.D.

[maineSS]

There is no dipstick tube on this engine- the dipstick cap sits flush on the block. There is pressure when the engine is revved up- oil vapor comes out the PCV tube on the oil fill pipe if you disconnect it during revving, the engine does need a rebuild. The PW doesn't have a road draft tube, crankcase vapors are routed into the intake manifold from a fitting on the passenger side of the engine, while air is taken from the carb mouth to the oil fill by a tube- this was to accomodate the hours of stationary operation as a power plant for sawmills, silage choppers, generators, etc Dodge expected the "Farm Utility Truck" to see.

The front main and rear main seals appear to be tight, but there's another leak on the other side, either valve covers or fuel/oil pump seals. I did the valve covers and fuel pump awhile back, but may not have totally fixed the problem.

[maineSS]

I went to a friend's house to look over two of his older PW's, and found another dipstick setup like mine on a '47. It seems later engines did have a tube of varying lengths. A picture of an M37 engine showed one that appears to be ~10" long, VPW carries a replacement stick & tube which would probably solve the splash problem as it has a rubber seal. If I go that route, I now have to determine if my oil sump is the same depth as the one they used as a model for proper dipstick length- nothing is ever easy!