Oil in anti-freeze

1987 MAZDA B2000 ,SMALL AMOUNT OF OIL IN ANTI-FREEZE TRUCK RUNES GREAT 240,000 MILES . WHY DO YOU THINK I HAVE OIL IN ANTI- FREEZE BUT NO ANTI-FREEZE IN OIL??? could use any help on this one…thanks

A couple of clarifying questions. Does the truck have an automatic transmission? Does the engine have an oil cooler? Can you determine if the oil in the anti-freeze is engine oil (brown) or transmission fluid (red)? The answer to these questions will help narrow the diagnosis.

Hope to help.

The leak is obviously where the coolant passages seal to the engine or block near a pressurized oil passage or even the combustion chamber, if you have a lot of oil burning. This is possible with head gasket leaks.The cooling system is under pressure when hot, typically 13-16 psi. Coolant will spew from any leak, internal of external. Only when the pressure on the other side of the leak is higher will stuff get into the coolant. Like oil pressure at 40 psi, or combustion chamber by-products at even higher pressures.

STANDARD TRANS NO OIL COOLER ENGINE OIL FOR SURE TODAY I LOOKED AGAIN AND SAW A LITTLE ANTI-FREEZE THAT LOOKED LIKE IT HAD DRIPPED FROM THE LOACTION OF THE WATER PUMP??? PLUS NO OIL BURNING AND RUNS VERY SMOOTH?? THANK YOU

NO OIL BURNING AND TODAY I LOOKED AGAIN AND SAW A LITTLE ANTI-FREEZE THAT LOOKED LIKE IT HAD DRIPPED FROM THE LOCATION OF THE WATER PUMP AREA THE PUMP IS BELT DRIVEN INTERNALLY THANK YOU

So you have the 2.2L with the timing belt? There was a 2.6L option with a timing chain, but the water pump is driven externally. It appears the oil pump and the water pump are very close together. Maybe there is some sort of transfer of fluids between the two causing this. But, I’m leaning more to a possible leak of the head gasket. You can rent a cooling system pressure tester at Autozone and some other parts stores. You only need to pump it up to the limit of the radiator cap, like 13 psi or 16 psi, and see if it holds. If it drifts down, you have a leak. If it holds steady for 10-15 minutes, it may be OK.