Milky substance in our oil

Does that mean that antifreeze is leaking into our oil?

It indicates the presence of water or coolant contamination of the oil.

If you are in the habit of doing a lot of short-trip driving, or if your cooling system thermostat is stuck in the open position, and if you do not change the oil every 3,000 miles, this could simply represent the moisture that is a byproduct of combustion that is not being burned off. That is not a good situation, but is is better than a bad head gasket or a bad intake manifold gasket leaking coolant into the oil supply.

In any event, you need to have this situation evaluated a.s.a.p. because water is not a lubricant, and your engine could suffer severe damage–if that has not already taken place. Take it to a competent mechanic at your earliest opportunity.

If your car is old, it could also be combustion blowby escaping past the piston rings, or antifreeze leaking into the crankcase. For every gallon of gas burned, you get a gallon of water. As per other post, short trips and cold weather operation with the egine not realy getting hot will eventually have 1/3 of the content of your crankcase filled with water, which is a really bad lubricant.

Suggest you take the car on a long highway trip, 40 miles or so at normal speed. Watch the temperature gage; it should reach operating operating temperature. If not, you need a new thermostat. Check the oil level after the trip; it will likely go down as the milky stuff (water)evaporates.

If the thermostat is OK and the milky stuff returns, you likely have a worn engine or a coolant leak somewhere. In either case, you are in for some serious engine work if you want to correct the problem. Please tell us the make and mileage on your car and how often you change oil.

Oh dear… Yesterday our car died and wouldn’t start out of the blue, and the battery seems to be holding a charge just fine. We had the alternator tested (which my husband and his dad just rebuilt almost exactly a year ago), and that seems to be just fine. The folks at NAPA suggested we look into the head gasket idea (gasp!). We just moved to the area, and are afraid of the mechanics here. My husband is back in school, so we’re living off of school loans and scholarships for the next year. SO - all that to say, we were just going to wait to have my husband’s dad take a look at the car first when he comes to visit in about 3 weeks. Is it reasonable to wait that long if we only do light driving (grocery store, driving my son to school two mornings a week, driving me to the hospital sometime in the next 3 weeks to have a baby (!) - everything else we can walk to) in the meantime?

Hmmm, I thought I hit submit, but it doesn’t look like my answer was sent out. If it was, I apologize for the duplicate response!

We have a 1985 Saab 900-S. The oil is changed at the very LEAST every 3,000 mi - normally before. My husband and father-in-law do the change.

Mileage is currently 213,606

If the car is used only for short-trip driving, it needs to have the oil changed every 3 months–regardless of how few miles were accumulated in that time period. How many miles do you drive per year with that car??

Good to know. I’m sure my husband and his dad know this, though - all I know is that THEY’RE fanatical about it! :expressionless: I do know that my husband has already changed the oil twice since we’ve moved here, and is going to do it when he gets home this evening.

Let’s see here, let me do the math… We moved from Seattle to eastern Washington last September, and from about September to…February…we were driving back to Seattle about every two weeks for my doctor appointments. So that was quite a bit of mileage - almost 600 miles every two weeks for 6 months. Here, we really only use the car 2-3 times per week (hardly ever driving more than 5 miles away), and in Seattle we probably didn’t ever go over 4,000 mi per year (and since we used the bus system often, the mileage would only be that high due to ski trips during the winters, so even that calculation would vary).

You have one of the rock solid Saabs of old, 25 years old. Over those years the car is used less than 10K miles per year and it sounds like even less per year lately. After the oil change put some miles on the car and keep checking the oil. You may just have some oil with moisture from condensation rather than coolant leaking into the oil. Hopefully that is the case. Since your husband is doing the changes you might consider a full synthetic oil which will handle the water better if it is just condensation.