In a moment of stupidity I poured a bit of engine coolant additive in the engine oil thinking it was engine oil bottle without reading the label (stupid me)

I have a very Touareg.

What are the implications? Do I need to flush it all?


  • Welcome to Motor Vehicle Maintenance & Repair! How much went in? Commented May 14, 2019 at 16:07
  • If it was only a little bit (maybe a couple hundred milliliters) it'll probably evaporate away fairly quickly with almost no issue. If you put enough in that you can see it in the oil when you pull the dip stick, or if the oil looks creamy/frothy, then it would probably be good to drain the oil/coolant additive and replace it. Water isn't lubricative, and I'm assuming the additive is mostly water. Any other minerals in it will remain after the water evaporates, and without knowing what they are it's hard to know what they'll do, although they will probably be trace enough not to matter. Commented May 14, 2019 at 16:11
  • Probably less than 500ml
    – Ionel
    Commented May 14, 2019 at 16:11
  • 1
    @the_storyteller the water in the coolant may evaporate away fairly quickly, the glycol etc won't and it is this that will cause the problems. Creamy/frothy oil is indeed a Bad Thing(TM) but direct addition of coolant will be causing problems long before you see that symptom. Commented May 15, 2019 at 8:45
  • Don't drive it until you have changed your oil and filter.
    – 3dalliance
    Commented May 15, 2019 at 15:19

1 Answer 1


500ml isn't a lot - but it's enough to cause problems.

Assuming it's a glycol-based coolant it can rather seriously affect the oil's performance increasing viscosity and reducing lubrication - potentially even causing blockages in the oil filter.

What to do next depends on whether you've started the engine since you added the coolant, if you haven't you can get away with "just" dropping the oil and replacing it. If you have I'd do a full oil + filter change.

  • I have started the engine as I needed to get home. I think to be safe I will arrange for an oil change ASAP however I need to move around so I hope nothing serious happens .
    – Ionel
    Commented May 14, 2019 at 16:32

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