Water leaking through hole in oil filter

I just found a big pin hole in my oil filter. It is leaking coolant. what does this mean?

It means that you have coolant in your oil passages and a leak in your oil filter.

It could also mean your head gasket is history. We’d need to know a lot more about the truck to speculate. How many miles are on it? What engine? Has it been running rough? Have you been losing coolant? How well has it been maintained?

If, in fact, you do have coolant in your oil, you’d better get it out of there and figure out how it got there (a compression leakdown test is in order here) or your engine will quickly become a boat anchor. Coolant makes a lousy lubricant. It hasn’t got the properties to keep the necessary pressurized barrier between the crank’s wear surfaces and their respective bearings, or to stick on the cylinder walls and help the piston rings slide smoothly down the cylinder walls…

The Filter Probably Should Be Changed. When They Rust Out They’re Just Not Much Good Any More.

Left in place for several years, an oil filter will rust from the inside, especially if the engine is full of a water/coolant type of “lubricant”.

While the mechanic is fixing to change the oil and filter, inquire as to why coolant runs out of the oil filter. Do this before spending any money on the oil change.

What model-year was this F-150 ?


it is a 1990 f150

It would be impossible for anti freeze, bright green or pink in color, to leak from the oil filter of an engine that has been running. If anti freeze is in the oil the mixture would look like a day old milk shake.

What engine? If this truck uses a filter that mounts to a removeable oil filter flange it could be that the gasket between the flange and engine block is leaking.

If the engine is a small block V-8 it could be that the gasket between the timing cover and engine block is rotted out and/or the timing cover has been eroded in that area. This will allow coolant from the water pump to mingle with engine oil.

No matter, coolant in the oil is bad news for an engine. This must be fixed immediately and it could be that coolant is leaking because oil will have a tendency to float and coolant sink to a lower point in the system, as in the oil filter.

BS alert…Any “pin-hole” in an oil filter will be spraying so much oil it would be impossible to detect any coolant in the oil…Within a few minutes, the crankcase would be emptied… If the engine lubricant was 100% coolant, the entire problem will resolve itself in very short order…

maybe it has a faulty oil cooler