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Running engine with no oil

My future son-in-law took his 2007 Nissan 350Z to the dealer for an oil change. When he got home (after driving about 50 miles) it was making a strange noise. He checked the oil and there was none on the dipstick. I had him start it in the driveway and the oil pressure came up to normal, then right away went to zero. He had it towed to the dealer and watched as they drained about one quart out of the crankcase. The dealer checked the oil for metal shavings and said there were none. They filled it with oil, test drove it and said the engine was OK. They said the noise was the "timing chain sensor losing pressure". I think this must have caused some engine damage. I don't understand how the engine didn't seize (unless the oil pump was able to intermittantly suck up some residual oil). What do you think? He needs to decide whether to accept what the dealer says, or play hardball and demand a new engine. Thanks.
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  • edited January 2010
    With only one quart in the crankcase there is engine damage no doubt about it and you're correct about the residual oil.
    I would certainly not buy into that hokey no shavings in the oil diagnosis so everything is fine.

    A compression test could be done which could possibly verify any top end damage to the rings and an oil pressure test could be done to possibly determine any lower end damage to the crankshaft journals and bearings.
    In my opinion, the oil pan should be dropped and several bearings caps located the fartherest away from the oil pump should be removed and inspected. There's about a 99% chance the overlay has been wiped away at a minimum and they're scored at worst.

    They screwed up and it's in their financial interest to whitewash the problem. If the engine is hammering 6 months from now or scatters itself they will have the out by claiming if there was a problem it would have occurred at that time.
  • edited January 2010
    Agree with ok4450. Is the car dealership acknowledging they screwed this up? This is why they have insurance, and I believe you have a legitimate claim. Ask for the name of the dealership's insurance carrier. If they refuse to give you the info then get a lawyer. I'm sure the service dept. mgr would rather the dealership owners never hear about this, which is why you need to make sure the dealership owner and business manager are informed.

    Towing the car back to the dealer was a good move. It makes is harder for the dealer to put the blame on you. Document the mileage at the oil change as per the invoice and the number of miles driven since leaving the dealership. Make and keep careful notes about everything, who the service writer was, who said what and when. Has it been determined that no oil was put back in the motor, or did the oil leak out from a defective filter, or unsecured plug in the oil pan?

    The only action you could have taken to avoid engine damage was to check the oil level at the dealership before driving the car home. This is a good practice but the assumption is the car is ready to drive when the bill is paid and you get your keys back.
  • edited January 2010
    Not every drop of oil inside of an engine drains out when the drain plug is removed.

    There is about a quart of oil tied up filling the oil passages, priming the oil pump, coating the interior of the block, etc.

    If 1 quart drained out, there was enough oil in the pan to wet the sump at least intermittently, and quite likely enough to maintain oil pressure.

    The sump is extremely close to the bottom of the pan, and given the fact that you cannot drain the circulating volume of oil (you can only drain the reservoir, about 4/5ths of the total volume of oil) you can assume that there was just enough oil in the pan to keep the sump wet and maintain oil pressure.

    Yes this oil has probably been cooked.
    No, it wasn't good for your engine by a long shot.

    But did it toast your engine? Not likely. If the low oil pressure warning never activated, you're fine. The noises were probably caused by the oil foaming. I'd say your son caught their mistake just in time.

    There's no need for any compression test. Unless you have documented a previous compression test, you have no baseline to determine if there is a loss of compression, unless it has such an obviously low set of readings that you would have felt power loss anyway. Without instruments telling you so.

    If significant engine damage occurred, you'd experience a remarkable, immediate loss in power, accompanied by a distinctly different exhaust note.

    Indeed, if you actually experienced a continuous loss of oil pressure, the engine would have lost a significant amount of power in a minute or so, and seized completely by 5 minutes or so.

    The dealership [i]should[/i] have to eat the cost of replacing an engine just for being stupid. But I'm very confident that your engine handled the abuse with minimal wear.

    If you want to examine anything, examine the cylinder walls with a bore scope. If they aren't absolutely trashed, then nothing, and I mean nothing in that engine is damaged. Also, compare documented fuel economy before and after the affair. Damage will manifest itself in the form of significant loss in fuel economy (ie greater than 10%). But time will tell for sure. If it makes it 5k more miles, it will make it 100k more miles. Just be sure to change the oil more frequently the next few oil changes to help flush out the foamed up overheated oil from this botched oil change. And steer clear of that dealership.

    If you want something done right, you have to do it yourself.

    -Fleet manager and primary mechanic for a construction company with 10+ vehicles, for 10 years.
  • edited January 2010
    Do you have something in writing from them stating that there was only one quart left? If not, get that immediately.

    Out of curiosity, what happened? Did they forget to fill it? Did they leave the filter or the drain plug loose?
  • edited January 2010
    On the subject of getting things in writing, I'd ask for them to put it in writing that there's no damage to the engine, just to see if they'll stand behind it.
  • edited January 2010
    They forgot to fill it. Thanks everyone who posted replies. This is helpful.
  • edited January 2010
    Any metal shavings would probably be in the oil filter. If they didn't replace that, then hold onto it when the oil is changed next. Might have someone else change the oil and have them cut open the filter.

    I don't think they will find any metal shavings though. Any excess wear will probably be in the form of fines, not shavings.

    I tend to agree with OK4450 and uncle turbo. You may not have lost oil pressure so its not likely that you had metal to metal contact, but with so little oil, the oil would have had to circulate so much more often than normal that it would have gotten very hot, thereby loosing more viscosity than it normally would, and that would lead to some increased wear.

    The fact that it was new oil and he only went 50 miles is good. It probably means that the engine will last as long as he owns the car, but down the road, some future owner will experience a premature engine failure, but then, they may attribute it to hard driving.
  • edited January 2010
    My only comment to an otherwise "C" level piece of writing is that if our "coustomers" (the people that ask us for advice here) used your 10% reduction in fuel mileage to indicate a mechanicaly damaged engine we would be flooded with posts asking what type of engine damage we think they have.

    Your mileage can change by 10% for so many other more likely reasons than engine damage.

    Dont for one second believe that an entire quart of oil is left in your engine after an, at temperature drain plug removal.6oz at most.
  • edited January 2010
    Something does NOT add up here.. If they forgot to install ANY oil, then any "residual" oil, oil left in the engine after it was drained would be pumped into the new filter and there it would have stayed. There would not be a DROP in the crankcase and the engine would have seized up long before 50 miles was driven. Not only does the car have a pressure gauge but it also has a warning light which would have been glowing unless there was oil pressure.

    You can demand a new engine all you want, but until you can PROVE engine damage, you will not get one. Get a letter from the dealer admitting their negligence and then wait and see. Any serious engine damage will manifest itself rather quickly..
  • edited January 2010
    OK here's how it works. They put only one quart of oil into it. That quart got pumped into the oil galleries and the upper part of the engine. Then the pump ran dry. Then the quart of oil drained itself back down into the pan to be sucked up by the pump again. In my experience this up and down happens about three times before damage begins.

    Note, they do not necessarily owe you a new engine. The do owe you one of similar mileage to the one they have probably ruined. Since the car is fairly new, there should be good ones available from salvage yards. See http://www.car-part.com
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