2017 Ford Mustang botched oil change

So I took my car to the dealership for an oil change and they never drained it and then added another 8 quarts to it. I have put about 300 miles on it since. How bad is this? I contacted them they want me to tow it to them and they are going to fix it. What concerns should I have over this? P.S. It only smokes on start up that I can tell

If you haven’t catastrophically destroyed the engine - and by your post, you haven’t - the dealership will drain the extra oil, check for any issues and give you your car back. The car should be OK.

But… KEEP ALL YOUR RECORDS on this! I can’t stress that enough! If any future engine issues arise you want all the evidence that this happened, the dealer admitted fault and you have proof.


That’s not good on a new vehicle.

When the crank case is overfilled with oil, the crankshaft lobes can whip air into the oil. The oil pump isn’t designed to pump aerated oil, so the engine gets starved of oil.

When you bring it to the dealer, ask that they perform an oil pressure test to determine if any damage was done to the engine.


Lesson learned: Always check oil level immediately after any oil change.

There has been a trend over the past so many years in which new car dealers are trying to compete with the Jiffy Lubes and chain operations. This means quite often 30 or 40 dollar oil changes which include a tire rotation and a 1000 point inspection.

This in turn means they need someone working on the cheap. A competent mechanics is not going to work for peanut shells so they turn to young guys who have little or no experience to perform those jobs.

And they give them a whole five minutes to change the oil & filter and do a 1000 point inspection. :persevere:

It’s sad to read of an OP that did everything right, including using the dealership for the oil change, having something like this happen.

I’ll take the liberty of suggesting this as a learning experience; always check any work performed to the extent practicable before starting the engine and driving away. In this case, it would have meant checking the oil level and looking under the vehicle for any signs of leaks. I always do. This life’s lesson could save you from a major disaster in the future.


How can they add 8 quarts to an engine from which they didn’t drain any oil beforehand?

Because 8 quarts will fill the engine clean up to the valve covers. That can be the reason for the oil smoke on startup. The oil pooling around the valve guide bosses will seep down the stems into the intake and exhaust.

We had a guy once add 10 quarts to a 4 quart VW diesel. He disappeared at lunch and never came back. I discovered the engine was hydro locked and managed to salvage it. Thankfully (and through sheer luck) there were no busted pistons or bent rods. Pretty amazing considering the diesel compression ratio.

When the oil cap was removed the entire valve cover was full of motor oil and there was simply no place for it to drain back down.

Ask them to drain ALL the oil out and sieve it for metal debris. If no metal debris, pieces of snap rings, pieces of gasket material etc is found, then they should replace the filter again, and refill w/oil of the correct spec for the engine. You have some responsibility as the owner of the car too w/this process, to check that the oil level is correct and there are no obvious leaks under the car before you drive away from the shop, then again when you arrive at your next destination (or 5 miles, whichever is nearer), and once more, the next morning before starting the engine. Meanwhile keep an eye on the oil pressure warning light until you’ve driven the car a few days and verified the oil change was done correctly this time.

Make sure you maintain a complete record of all this in writing, in case an engine problem comes up for which this might be the cause. Suggest to write what happened down, days and times, the names of everyone at the dealership who is involved, and mail that letter to the dealership owner via registered mail w/return receipt, keeping a copy of the letter for yourself. Ask that the owner carefully review your letter, and write back if they disagree about any of the facts.

Note: If this engine uses a pcv valve, that should probably be replaced. At least the entire pcv system tested.