Extreme Oil overfill at dealership

Got my oil changed in my Honda S2000 at the dealership. After driving away I got several miles and notice lots of smoke behind me. It got so bad that I stopped in the middle of a busy street, it looked like my car was on fire, people were freaking out. I limped my way back to the dealer. They informed me they overfilled the crankcase, they said instead of 5 quarts they put in 5 gallons. Now 2 weeks later I got a check engine light, 2 days without the car only to be told the valves and head need replace and it had nothing to do with the oil overfill. The car is 4 years old with 38,000 miles and very well taken care of. Are they sticking it to me? Could the engine have been badly damage due to the oil overfill? What should I do?

darn new guys,hummmmmmm! 5 gals. i say no start,in any world. lets just say hydrolock.are you sure it wasnt midas,or autozone?


Yes, it is possible to sustain engine damage when the oil is overfilled.
A few questions are in order first.

After draining the excess oil out did the vehicle seem to run fine?
Did the vehicle run fine up to the time of this diagnosis of bad valves/head?
Exactly what reasons do they give you for the valves/head being bad?

If the valves/head is legitimately bad this means you should have a poorly running vehicle. Of course, I’m very skeptical of that diagnosis and especially with only 38k miles on it.
If they claim the valves/head is bad then the way this is determined is with a compression test. If they did not do this then you should take this claim with a large dose of salt.

Since the odds of a 38k miles Honda having a bad head/valves ranks right up there with the snowball in xxxx I would not do anything at this point. If it legitimately has damage then it was more than likely caused by overfilling the oil.
What happens is that oil can be forced into the combustion chambers and the engine may try to hydrolock, which can be damaging.

That’s about the best I can do without knowing the exact symptoms and why they claim you have a serious problem.

please 5 GALLONs do the math.

Where did I say or insinuate it was anything other than seriously overfilled with 5 gallons.
What I’m trying to do here is an attempt to discover IF the OP has engine damage, exactly why the OP is being told this, etc.

Being hydrolocked does not automatically mean engine damage. Obviously after most of the 5 gallons was drained the OP motored on down the road. I comprehend it just fine.

What math ?

Is it possible to get 5 gallons in an engine this size? Rocketman

I’m with rocketman…I seriously doubt you could fit anywhere near 5 gallons on there.

While the crankcase was undoubtedly overfilled, I don’t believe that it is possible to put 5 gallons of oil into the crankcase of that engine. That point aside–yes, I do believe that a gross overfilling of the crankcase could have caused your engine to hydrolock (or in this case, to “oleolock”).

I have to wonder whether you actually observed anything when you went back to the dealership or just got your info in the waiting room.

The reason I wonder is - as w/ rocketman Mike & VDC I doubt you can get 5 gallons in. And its more likely that the amount of oil they put in was zero. Lets assume for a minute that you do need a head/valve job - driving around with no oil is actually thing that could do this.

But how is the car running? As ok said - if its that bad it should be running pretty poorly. I would get it to an independent mechanic and ask them to test the condition of the engine. 5 minutes with a vacuum gauge would say a lot as well as compression test.

Maybe they had their trainee on the team that day…

…“No, no, no…I said fill the washer fluid to the top”

Good idea AA . . . a few tests by an independent will document the engine problems . . . document the code readings, the engines tests, anything that can be tested without taking the engine apart. Then you’ll have a good chance of getting this dealership to pay for your new engine. Good luck! Rocketman

“Lets assume for a minute that you do need a head/valve job - driving around with no oil is actually thing that could do this.”

Driving around “with no oil” would burn out the main bearings and rod bearings before the valves and the head would be damaged, IMHO. The engine would have seized up very quickly if there was no oil in the crankcase.

This is what the service advisor at my local Honda dealership told me was wrong with the car. I took some notes, because all this car talk is way over my head. Here is a list of some of the things he told me about the status of my car.

  1. Engine down on compression #1 cylinder

  2. Burning valves

  3. Loss of compression on #1 cylinder

  4. Faulty exhaust valve guide

  5. They are going to replace the following:

    a. Exhaust Head Valve

    b. Cylinder Head

    c. Intake Valve

  6. The car was misfiring only when the car was at idle.

He said the whole top end of the engine is going to be replaced. They are replacing this all for free, however they say it has nothing to do with the engine overfill. They are only doing this because corporate told them that they’ve had a couple of problems like this with this engine in this particular year model. And yes, the service advisor did admit that the technician did in fact put 5 gallons of oil in the car. I was there when they checked the oil, and oil was flowing from the hilt of the dipstick. The service advisor said that normally the only thing that will happen is that you’ll blow seals when you overfill a car with oil.


That shows how much service advisors are worth…which is practically zero.

The typical result of overfilling is that the crankshaft will be immersed in oil and whip it up into a froth, which the oil pump then tries to draw and lubricate the bearings with. Doesn’t work too well, so they get wrecked. You don’t “blow seals”.

Now, if you somehow manage to put five gallons of oil in (which I simply do not buy, unless half of it is on the shop floor…twenty quarts?), I suspect you’ll have a whole lot worse going on. What I might guess happened here is that the extreme overabundance of oil probably blew out the rings on the cylinder they’re talking about, and oil then found its way into there and hence into…well, everything. I’d seriously be on them for a new engine after this mess.

As a tech I can tell you that you should never, ever put much faith into anything a service manager or service advisor (writer if you prefer) tells you.

The vast majority of these guys have no mechanical aptitude and get through each day by blabbing a bunch of BS that may sound good to someone who is not mechanically inclined.

Now and then you’ll find some good ones with actual mechanical experience but they’re few and far between.

One cylinder that is low on compression can cause a rough idle and the engine may smooth out as you accelerate.

Here’s the problem given what you were told about a bad valve guide, burnt exhaust valve, etc., etc.
This has nothing to do with overfillng the oil.
What it does have something to do with is Honda’s idiotic recommendation about extended valve lash adjustments. I kind of harp about this on a regular basis because not only does Honda recommend this but Toyota and Subaru have done the same thing.

Valve lash (or the gap between the rocker arm/valve stem or cam lobe/cam follower dependent on the engine) must have a certain clearance on solid lifter engines. (Look in the owners manual or the underhood sticker for valve lash).
When neglected the gap narrows, especially on exhaust valves due to stem stretch, valve face dishing, etc. Once the gap disappears the exhaust valve, seat, and head may not last long.

In the interest of making their cars appear to be more maintenance free some car makers have extended the safe and sane time frame for checking this from 30k miles MAXIMUM to 90 - 120k miles.
This is not your fault because you only follow what the factory recommends - which in this case is dead wrong.

You’re not the only Honda owner to suffer problems from this; CRVs, etc. are also affected. Most won’t have a problem from this neglect but a certain percentage will due to inadequate valve lash; as you have found out.

This may help explain it a bit.

Is there not a powertrain warranty on Honda’s for 5yr/60k which would cover this? If not contact Honda higher up and explain situation.

Honda’s have a golden reputation not because the car’s are that great (significant power train issues in tranny’s) but they come through and cover things past warranty to hush and make customers happy like everyone should with defective products.

Personally, I think this service adviser and his shop are full of crap.

There’s no way in hell that a mechanic gets confused and puts 5 gallons of oil in a car instead of 5 quarts. Secondly, you couldn’t pour 5 gallons of oil in that car if you wanted to, there’s no where for it to go.

I would be demanding a brand new crate engine be installed by another dealer not the one that according to him doesn’t know the difference between 5 quarts and 5 gallons.

There’s nothing I hate worse than being lied to like that, and trust me, this is a complete lie. I don’t know what he did. I don’t know if they forgot to put oil in it, filled it 2 or 3 quarts too full or what. I know for darn certain they didn’t put 5 gallons of oil in your engine. I would demand to see the dealership’s general manager and have that idiot service adviser and mechanic explain to me in front of their boss exactly what they did to my vehicle and what was wrong with it. If that BS continues about putting 5 gallons of oil in that engine, I would let Honda Motor Co know what sort of a lie their dealership is trying to pull over on me. If Honda wanted to back up that stupid story then I’d be assured to next time buy something else, kind of like Me and Ford Motor Co.

I can’t stand being lied to and feel sorry for you having to put up with that.


You’re response makes the most sense to me. What should I be most concerned with for the oil overfill problem? The car will be ready this week for pickup after the valve head repairs. What about the cylinders and seals? Should they be replaced? A co-worker that knows a little about cars said that the bottom half of that engine needs to be looked at while they’re doing the top half. Do you agree? A lot of people are questioning the amount of oil that was put it. I only know that I was standing there when they checked the oil and oil was POURING off the dipstick from the highest point!!

I’m not going to argue over the amount of oil. Five quarts, five gallons, or whatver; it makes no difference. The car was overfilled pure and simple.
It can actually be pretty easy to overfill the engine if one is not careful due to the fact that many dealer shops use overhead oil lines. The person doing the oil change sticks the nozzle in the filler hole, clicks it on and locks the trigger, turns around momentarily to do something else, and loses track of the time. A minute later they return to the task at hand without realizing more time has gone by than they thought. It would be easy for even an experienced tech to do this if they were rushed and very busy.

I’ve seen a number of engines that were overfilled on oil and suffered no problems. Several of them were hydrolocked and one in particular (a VW diesel) actually was filled to overflowing at the valve cover cap.

Since your car was still running through all of this it never suffered hydrolock so that’s a big plus anyway.
I would adopt a wait and see at this point because my opinion is that the engine has not suffered any cylinder/piston or seal damage.

Since they mention corporate Honda is involved this means they’re performing this under a full factory warranty or what is called a “good will warranty”. This is exactly what they should be doing and obviously Honda knows full well what the cause of this is; and it’s not you or the oil overfill.

An example of how critical this valve lash thing is. Some years ago we had a guy come in with a near new Subaru, which also uses solid lifters with adjustable lash. This car was barely even moving with the pedal on the floor and it only had 7k miles on it.
A diagnosis showed that every single one of the valves were tight with no lash clearance at all. The damage was so bad that both cylinder heads on the vehicle had to be scrapped. They were too far gone to even be repaired.

The bad part in this case was that at the time Subaru recommended a valve lash check at 1k miles. This was performed free of charge to the car owner but the owner of this car ignored that recommendation. Since he chose to ignore it Subaru flat refused to pay for the entire repair and the owner had to foot a fairly large bill.
(Different deal in your case because you’ve done nothing wrong; just pointing out how quickly some bad things can happen). Hope some of that helps.