I poured a very small amount of old oil into the coolant reservoir. I have a mechanic that's 15 minutes from my house. Should I drive it there to flush it out - or have it towed there? (I don't have the tools needed in my garage, as I'm not a car person.)

Car is a 2001 Nissan Altima that already has a small oil leak.

  • Did you pour it into the surge/overflow tank or directly into the radiator? If so, just drain what's in there and you'll be fine. It is very easy to take a hose off to drain it, even with the most rudimentary of hand tools. Have you ran the car since you poured the oil into there? If you haven't, all of the oil you have poured in (assuming it was in the overflow/surge) should still be in the same place. Commented Mar 20, 2017 at 0:09
  • @Pᴀᴜʟsᴛᴇʀ2 I didn't start the car at all -- and it's (to my knowledge) the coolant reservoir? Where you put antifreeze in Commented Mar 20, 2017 at 0:10
  • Is this what your underhood looks like? If so, did you take the silver cap off in the center front? Or did you put it in the plastic jug on the left side (as per the picture)? Commented Mar 20, 2017 at 0:33
  • @Pᴀᴜʟsᴛᴇʀ2 looks just like that! I didn't take the silver cap off. I poured a little bit into the plastic jug for about 3 to 4 seconds before I realized it was the wrong spot Commented Mar 20, 2017 at 0:35

2 Answers 2


If you only poured oil into the overflow, you should not have any issues. If you don't have the tools to drain the reservoir, then take and fold the hose which goes from the radiator to the reservoir, then take some string or something like which can be tied around the hose. This will keep any fluid from flowing into/out of the reservoir. Then drive directly to your mechanic. Do not pass go. Do not collect $200. When you start the car, leave immediately for the mechanic. You shouldn't have an issue.

Obviously, the best thing to do is just drain the reservoir yourself. It would be really easy for you to do with even the most rudimentary of hand tools.

  • I did it just like this and I was able to ride to the mechanic with no problem! Going to put some stuff in the engine to clean it out so I make sure no crud got on the inside! The mechanic just drained the tank, cleaned it out and put new coolant inside. Works like a charm! Commented Mar 20, 2017 at 16:51

Shove a garden hose into the plastic jug, and fill it with water such that it floats the oil up and out.

Disconnect the small rubber tube, and drain out the water. Replace to the proper level with a 50/50 ratio antifreeze water mix.

I wouldn't panic. Oil will neither help nor harm your cooling system. Get it cleaned out, but no panic necessary.

It's when somebody adds gallons of water into the 710 or euro "watering can" pipe, and now you have huge amounts of water mixed with engine oil. This is the time to panic. Your situation is simple and easily resolved.

  • Oil floats on water : nice answer!
    – Solar Mike
    Commented Mar 20, 2017 at 5:57
  • I was so tempted to try this but strapped for time! Commented Mar 20, 2017 at 18:35

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .