I own Suzuki Swift diesel, the engine is 1248cc Fiat sourced diesel engine with a small FGT turbocharger. I overfilled the engine with about 1/2 litre too much engine oil and drove at high speeds on highway for about 80 kms. Could this cause damage to the turbo or engine. I have drained the excess oil. The oil capacity is 3.1 L and I poured in 3.6 L.

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    Likely not. The turbo bearing oil supply line should not be affected if the oil sump is overfilled. Are you seeing performance issues?
    – Zaid
    Commented Oct 8, 2016 at 15:17
  • @Zaid No performance issue that I can notice but I was concerened that could it cause the oil seals in turbo to leak or this 1/2litre too much oil could cause the crank to froth the engine oil ? Commented Oct 8, 2016 at 15:35
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    If you don't have any performance issues, I'd say even if there was a bit of damage, you couldn't assess it without more trouble than it's worth. You may possibly notice some performance issues because of it a few years down the road, but even at that, you're probably fine, as @Zaid said.
    – anonymous2
    Commented Oct 8, 2016 at 16:35
  • @anonymous2, and a few years down the road it will be very hard to pin the damage on this overfilling. What concerns me more is that the oil level appears to be rising – see the comment on my answer below.
    – dlu
    Commented Oct 10, 2016 at 23:58

1 Answer 1


It would be hard to give you a definitive answer without access to the engineering data for the engine (unless there are folks out there with real-life experience), but it seems quite unlikely.

Half of a litre isn't much oil and it is well within the range of "reasonable" mistakes: accidental overfilling, filling to spec without changing the oil filter, adding quarts instead of litre, etc. So, I would expect the design of the engine to allow for this.

Consider also that, 1/2 of a litre spread over the area of your oil pan won't result in much of an increase in the oil level. I'd guess that it would be less than the amount of sloshing from side-to-side during heavy braking or cornering.

All-in-all I think it is highly unlikely that you've done any damage – especially since you're not seeing any change in the engine's behavior.

  • I today just checked the dipstick right after I stopped the engine and found around 5-6 air bubbles(not froth) on the end of the dipstick. Is this normal as the level of oil is just 4-5 mm above full mark. Commented Oct 10, 2016 at 17:03
  • I've never seen bubbles when checking the dipstick, that's puzzling. The oil being above the full mark just after stopping leads me to think that the level will go even higher as it drains down. What concerns me is that you'd already drained the excess, no? The engine shouldn't be "making" oil – that suggests either a fuel or a water leak. Fuel would probably mix in, but water could end up looking like bubbles. Are you sure it was air?
    – dlu
    Commented Oct 10, 2016 at 23:56
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    I don't know if this is the case in diesel engines, but in small engines, frequently the position of the engine makes a slight difference in the apparent level of the oil. If you run the engine again and stop it, do you get the exact same reading? @user3855004
    – anonymous2
    Commented Oct 11, 2016 at 0:02
  • No they were just air bubbles and coolant level is not dropping so I dont think there is any water leak in the engine, Couldn't they just be the air bubbles due to the sloshing of engine oil in the sump over the uneven surface of the road ? For experimenting I took same engine oil which was left from last oil fill and shaked the bottle and found same air bubbles like the ones on the dipstick. Could this be the case ? Commented Oct 11, 2016 at 3:10
  • And I had drained the excess oil the very next day it was overfilled and the level seemed just at the max level. If I run the engine again and check the level it is between the min and the max level with very very small air bubbles. Commented Oct 11, 2016 at 3:16

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