Too much oil

How much extra did it take for the CEL to come on !? morel of the story check oil level (also check for leaks) b4 driving away.

 

Hmm, I am wondering why an oil overfill would cause cyl 2 to misfire, if this did not foul the cyl 2 spark plug. Anyway, if the CEL is out, you don't notice any driveability issues, and you don't see any oil leaks (coming from your crankshaft seals) then "no-harm, no-foul".

My guess is that your crankcase was at least 1 quart overfilled to cause this problem (i.e., 5 qts were added).

 

Whoa! Who overfilled the vehicle's oil? The dealer? Did you get this all well documented as to who is was responsible for this mistake (assuming it wasn't you)? ANY future problems with the engine internals, fouled plugs, valves, cleaning of the throttle body, MAF, EGR, cat failure, O2 sensor issues, etc. could very well be the result of this.

Thanks for reporting it. How much extra oil was showing on the dipstick, in inches, (realizing that considerable excess had already been pulled through the intake and into the cylinders.)

 

It cannot be overstated: Always, Always, Always, check the oil level yourself before driving away from an oil change, no matter who does the changing. Nobody is perfect. Checking can save you from many annoying or expensive mistakes.

 

That is the primary reason I'm doing my own maintenance - I know it will be done correctly. I always fear when something breaks that is more than I can do - how do I know that it will be done right?

Let's take break service and bleeding the breaks. On the Prius this requires special tools and knowledge to do. If they screw up a simple oil change, how much worse for a break job on the Prius? <shudder>. OTOH, the Prius breaks last so long that this particular scenario may never have to be put in play!

Rumple

 

It's a funny thing. Working in engineering design and manufacturing has shown me that the simplest things are more likely to get screwed up because people assume that the simple things *can't* go wrong, and so they become complacent. With complicated things they're more anxious and therefore vigilant.

Concerning oil changes specifically it's often the lowest paid people who get assigned to them.

 

Hard to say. If things appear to be normal and the car does well over a few tanks of gas, then it is probably okay. If you've been able to get 57 mpg before, then obviously you have the vehicle pretty well dialed in and the car you have seems to be a good performer. So I would be hesitant to sell it (for one that might not perform as well) unless the ICE starts having substantial problems. If it does have major problems, the dealer gets to pay for a new ICE.

I would check/measure the oil level periodically right up to the next oil change, just to see if you are getting any consumption as a result of the overfill. If the oil was frothing (during the overfill) you may have gotten some bubbles in the lubrication loop that would lead to excess wear during the period when it was overfull (not now.) If you don't see any significant oil consumption then it probably didn't cause significant wear. I'm not sure that you would know there was trouble in the bottom end (crank) until something actually started to break down as it wouldn't show oil consumption since the oil wouldn't escape into the combustion chamber.

On the top end my first concerns would be with spark plug fouling, MAF fouling, EGR fouling, and throttle body deposits. Plugs are no big deal of course, and as long as there is no additional oil ingestion the others should be straightforward to address if problems arise--just remind the dealer why and let them pay for it if they come up. Valve issues would seem unlikely in a short span, and if they did might show up as oil consumption due to leakage past the valve guide seals.

It probably wasn't enough oil to foul the catalytic converter or O2 sensors. (I'm not sure how much of an oil leak or how long it would take to degrade them.)

It might take awhile for all of the oil to work its way out of the intake and I wouldn't be surprised if the air filter dirties rapidly for awhile.

I guess what I'm saying is, keep a close eye on it for awhile and make sure everything is back to normal before making a decision. If it is normal then you are likely best off hanging onto it.

 

I really think that your car will be fine. For fun, you may want to remove the top of the air cleaner housing and look into the throttle body when the car is IG-OFF. Rotate the spring-loaded shaft to open up the throttle plate and see what the bottom of the intake mainfold looks like (might need a flashlight or trouble light to get a better view). Do you see a pool of engine oil?

 

I, too, had my oil overfilled by a little over one quart by a NTB (National Tire and Battery) when I had my tires replaced. I noticed a drop in my MPG from 55 average to 49.

Once the extra was removed (note: there was no frothing) I drove for 1K hoping that the MPG would increase - but no. Looking in to the throttle-body I saw a pool of oil. I cleaned that up and then took the car in to the dealer for them to look over all parts that could have been screwed up. They cleaned a component (can't remember which) but that didn't help either.

It's been 20K and my MPG just now began to creap back up. I'm now averaging 53mpg per tank.

Yes... I did learn my lesson!

 

Wife has 2001 G1 with 165K on it. Says it started "bucking" when she got off the freeway coming home. When I hop in it's fine.
OK she starts driving my 2007 G2 so I can see for myself. Runs great for two days locally. By now I'm convinced she just wants the new car
Ran an errand on the freeway today and sure enough I take the exit and it starts bucking as if missing a cylinder or two. In fact smells strange like an engine that has huge timing issues. Drive straight to Toyota so they can see and get codes.
Tech drives 50 feet and says "did this start after you changed the oil"? I'm dumbfounded but yes. He says happens all the time. Crank splashing in the oil causes the engine to slowdown which the computer picks up on as a misfire.
Drive home still bucking, drain about 1/3 quart which brings it to 2-3 mm under the line (this is not seriously overfilled). Start up same thing.
Sits for a few hours , OK.
I'll drive to see if behavior changes and after reading this thread will look for evidence of oil through the throttle body etc.
Thanks

 

I'm also wondering if your MAF and/or TB was dirty? As far as a puddle of "something" in the intake, I have that too and I've never overfilled my Prius

One thing I did notice is that this summer my FJ began to act - strangely. Didn't seem to have the pep it used to, sometimes the auto shifted a bit weird, rotten egg smell when I backed into the garage, and slightly lower fuel economy

Some FJ owners have commented on the MAF having deposits from running an aftermarket K&N or other oiled aircleaner. I only use the dealer paper air cleaner element. Since the FJ MAF is super easy to remove and inspect, I did so when I changed the spark plugs this week

I was pretty surprised to notice a grayish residue on my MAF. I posted photos in another thread here, but the MAF temp sensor bulb was covered with the residue. My camera wasn't capable of zooming into the guts of the MAF where the two hot wire sensors live, but the wires also had what looked like ash coating them

You can safely clean hot wire MAF with an approved cleaner. One such cleaner is CRC Mass Air Flow Sensor Cleaner

CRC Industries Global Home

There was a huge difference in how my FJ ran after I cleaned the MAF sensor. Given the age of your Prius, it may be time to do so. CRC and 3M also market special throttle body cleaners, which I used last year on my Prius. I may clean the FJ throttle body next year.

My only explanation for the ash-like deposit on my MAF is that oil vapor from the PCV will, over time, create deposits in the MAF and TB, depending on where they are located.

An overfill *might* have introduced more oil vapor, possibly that was enough to cause problems

I used to have a 2000 GMC Sierra with Vortec 5.3 V8. The MAF was located next to the aircleaner box, and I never cleaned the MAF on that vehicle. However, I did have to clean the TB and IAC at least once a year, towards the end I routinely cleaned the TB and IAC every spring and fall

My IAC (Idle AIr Control) pintle valve and IAC passages in the TB would become clogged with oil residue. That year truck had a known issue with an overly-aggressive PCV drawing too much oil vapor, resulting in deposits inside the intake manifold, especially if operated in a very cold climate. A TSB had a different PCV valve, which then resulted in a very nasty whistling sound at idle

Of course, once I had the IAC motor off, and everything properly cleaned, I then had to go through the Idle Learn Procedure, or the truck would idle weird. A day in the life of a GM!

 

I just had my first oil change. I took in 4 quarts of Mobil 1 and said I wanted that put in.

They gave my the car back with no extra oil. I assumed they tossed the extra that should have been left over. No big deal.

When I got home, I checked the oil, and it's 1/4 to 3/8 inch above the upper dimple in the dipstick. I think they put in all 4 quarts. Should I be concerned?

Based on what some have said in this thread, I am a little worried now.

Mike

 

It's possible to use one of those extraction pumps to suck the excess out the dipstick tube. You can usually pick those cheap pumps up at Autozone or similar places for $20 or so.

There really isn't a concensus on overfill. Most of the dispensing equipment at dealerships is grossly out of calibration anyway, and always appear to overfill.

If it was half an inch or more above the full dot, then I would worry about it