oil consumption stopped due to overfill, safe?

[Luis_G]

Hey guys in my previous thread I reported oil consumption on my 99 corolla with a 1ffze engine with a rate of 1 quart per 500 miles. This rate is not exactly and it can go higher or lower. Usually after an oil change, it stays stable for about 1-2 days then it starts to drop.

I had done my very first OCI using Quaker State Ultimate Durability oil back towards the beginnings of October, and I over filled it a bit over when I miscalculated how much oil would go into the filter. I poured what was left of teh 5qt jug into a 1 quart and it's reading about .75 quarts (250ml ish missing, which is roughly .26 qurts).

So I added about 4.26 quarts of oil into a 3.9 quart engine.

I've been checking the oil regularly, and it stays at the same level. So far it seems oil consumption has been reduced greatly, or it has stopped.

So I have 2 questions:
1. Would keeping it overfilled about .35 quarts~ (3.9 quarts vs 4.25 quarts put in) cause issues with the engine?
2. Why would oil consumption stop?

So far engine has been running good, only issue I've had was a few days ago where I heard some weird sounds when I revved my engine in idle, sounded like air thumps coming from the engine. I tried to replicate the issue later but nothing. I know revving is bad for the motor so I am not too concerned, but just thought I'd mention it.

 

[UNC017]

I doubt that over-filling had any effect on actual consumption. Remember that the dipstick isn't linear because the oil sump isn't an exact rectangular cross section. Removing xx ounces when its above the full mark may only drop the indicated level by 1/2 millimeter, whereas removing the same xx ounces when its down below the full mark may drop it several millimeters.

 

[Luis_G]

I see what you are saying. Makes sense. I couldn't really think of a reason why extra oil would prevent consumption.
Man I have been learning a lot of oil and engines recently. It's a lot of fun.

Regarding the overfill. Would it be recommended to remove the extra .35 quarts? Or should I leave it?

 

[nwjones18]

I would just leave it in there.. anything under 1/2qt overfill is no big deal IMO.

 

[Gokhan]

(1) Overfill is never safe. Get a suction pump and suck the excess oil from the dipstick.

http://www.blackstone-labs.com/vacuum-pump.php

(2) Oil consumption hasn't stopped. You just can't see it because the level is at a nonlinear area of the dipstick.

 

[MONKEYMAN]

Dealership overfilled my 93 Sentra for 75,000 miles of free 3,000 mile oil changes. Sump was 3.5. They put 4 quarts every time.

I intentionally overfill 1/2 quart on my Saturn SL2. I have been advised by those with technical knowledge this is OK.

If it is never safe, I would like to know how you determine that.

 

[Luis_G]

I am going to ahead and remove the excess oil.

 

[Gokhan]

Originally Posted By: MONKEYMAN
I intentionally overfill 1/2 quart on my Saturn SL2. I have been advised by those with technical knowledge this is OK.

There is a tolerance of course. If it specifies 5.0 qt, it won't get damaged if you put 5.1 qt. When do you start seeing excess wear or damage? At 5.5 qt? 5.6 qt? 5.7 qt? I don't know. The problem is that once the oil level reaches the moving parts, you get foams and lose lubrication, which could result in quick engine wear or damage.

Therefore, I would always fill with the specified capacity or fill it to no more than a few millimeters over the Full-mark line.

 

[Gokhan]

Originally Posted By: Luis_G
I am going to ahead and remove the excess oil.

Reading your post completely, I probably wouldn't worry about only 0.35 qt of overfill. You can keep it as it is. Don't overfill it next time for peace of mind.

Regarding the oil consumption being slower first, again, it's only because the dipstick is nonlinear if you are not within the Low and Full marks. That's because of the volume geometry inside. The oil is still being consumed with the same rate or even higher.

To reduce consumption, simply switch to an xW-40 grade. You can use 0W-40, 5W-40, or even 15w40 without any issues. 15w40 will cut the oil consumption by about a factor of two and a half in comparison to 5w30. Therefore, you will see it dropping to 1 qt per 1,250 miles if you use 15w40.

I would recommend Mobil Delvac 1300 Super 15w40 in particular, which has a relatively low NOACK of 11.3%:

http://www.pqiamerica.com/June 2014/consolidated HDEO 2015.html

 

[Luisraul924]

Originally Posted By: Gokhan
You can use 0W-40, 5W-40, or even 15w40 without any issues. 15w40 will cut the oil consumption by about a factor of two and a half in comparison to 5w30. Therefore, you will see it dropping to 1 qt per 1,250 miles if you use 15w40.


This isn't accurate. There is no definite number or "factor" in which consumption drops. There are differences based on what's causing the consumption. Say the problem is worn rings, that amount of consumption would be different from an engine that is shearing the oil and evaporating it. A worn valvetrain would also cause some consumption as well and you can definitely bet that it would be at a different rate than the previous two I mentioned. Does that mean that a 40 weight oil wouldn't work? No, it may actually be the "cure" to his consumption issues. However, it is important to note that just because it's an Xw-40 doesn't mean that it would cut the consumption down by a definite factor.

Edit: to the OP, I wouldn't worry about 1/3qt overfill. I overfilled my sump by half a quart and it's doing just fine now.

 

[901Memphis]

I would not stress out about this slight overfill. Don't waste your time removing it, especially since it's consuming it will be on full in no time

 

[Gokhan]

Originally Posted By: Luisraul924
Originally Posted By: Gokhan
You can use 0W-40, 5W-40, or even 15w40 without any issues. 15w40 will cut the oil consumption by about a factor of two and a half in comparison to 5w30. Therefore, you will see it dropping to 1 qt per 1,250 miles if you use 15w40.

This isn't accurate. There is no definite number or "factor" in which consumption drops. There are differences based on what's causing the consumption. Say the problem is worn rings, that amount of consumption would be different from an engine that is shearing the oil and evaporating it. A worn valvetrain would also cause some consumption as well and you can definitely bet that it would be at a different rate than the previous two I mentioned. Does that mean that a 40 weight oil wouldn't work? No, it may actually be the "cure" to his consumption issues. However, it is important to note that just because it's an Xw-40 doesn't mean that it would cut the consumption down by a definite factor.

Edit: to the OP, I wouldn't worry about 1/3qt overfill. I overfilled my sump by half a quart and it's doing just fine now.

In my Corolla, which is very similar to his, the source of consumption was valve-stem oil seals. It would consume 2.5 qt per 1,000 mi with Pennzoil Platinum 5w30 and 1 qt per 1,000 mi with Mobil Delvac 1300 Super 15w40. Once I replaced my valve-stem oil seals several years ago, my oil consumption has stopped entirely. Now, I don't see much consumption even with 0W-20.

Since he has a very similar engine that is 16-year-old, his consumption source and possible treatment and cure are more than likely exactly the same.

 

[Luisraul924]

Originally Posted By: Gokhan
Since he has a very similar engine that is 16-year-old, his consumption source and possible treatment and cure are more than likely exactly the same.

The 4A-LC and 1ZZ-FE engines are two completely different engines. They're from entirely different generaions and just about the only thing they have in common is the fact that they are both four cylinder engines. The 4A was a 1.6 sohc 8 valve engine whereas the 1ZZ is a 1.8 dohc 16 valve engine. If he had the same issue you did he would be burning quite the amount more oil since he has twice the valves. Even still however it would depend on the amount of wear on the valve stem seals. His is a much newer engine and they may not be as worn as yours were. Both engines may be from Toyota but the 1ZZ is quite a bit more modern than the 4AL.

 

[Gokhan]

Originally Posted By: Luisraul924
Originally Posted By: Gokhan
Since he has a very similar engine that is 16-year-old, his consumption source and possible treatment and cure are more than likely exactly the same.

The 4A-LC and 1ZZ-FE engines are two completely different engines. They're from entirely different generaions and just about the only thing they have in common is the fact that they are both four cylinder engines. The 4A was a 1.6 sohc 8 valve engine whereas the 1ZZ is a 1.8 dohc 16 valve engine. If he had the same issue you did he would be burning quite the amount more oil since he has twice the valves. Even still however it would depend on the amount of wear on the valve stem seals. His is a much newer engine and they may not be as worn as yours were. Both engines may be from Toyota but the 1ZZ is quite a bit more modern than the 4AL.

Toyota hasn't changed the basic engine design and parts in three decades. Number of valves is not relevant to this topic. Main difference between his and mine is the fuel system. The seals used in both engines are very similar, made from same materials.

 

[Luisraul924]

Originally Posted By: Gokhan
Toyota hasn't changed the basic engine design and parts in three decades. Number of valves is not relevant to this topic. Main difference between his and mine is the fuel system. The seals used in both engines are very similar, made from same materials.


I beg to differ I've torn apart a few Toyota engines at school and while you can definitely see Toyota's "signature" engineering, they have made various small improvements to their engine lines throughout the years to improve efficiency. As for the number of valves... That's directly related to this issue, some Toyotas do have valve stem issues and the fact that his engine has twice the number of valves than yours that means he has twice the number of problems that can go wrong if anything were to go wrong, in this case it would be oil consumption.

 

[TFB1]

I doubt there is any engine that will be adversely effected by being a half quart over full... I'd surely not be one to worry about it...

 

[Luis_G]

Well I got a manual pump and pumped out .5 quarts. Added some oil back in so it's at about 3.9 quarts or "full" in the dipstick. Should be good now. I will just keep checking oil. Better safe then sorry and it only took few minutes!

Also while doing that I checked my spark plugs. They're about 7000 miles so not very old. I was told to check them every 5000 miles for oil.
2 spark plugs had oil on them. One had lots of fresh oil, the 2nd had old burnt oil, but didn't have any fresh oil. The first picture is one of teh dry spark plugs. The 2nd picture is of the spark plug with old oil.
The last picture is of all 4 spark plugs in order. The 2nd spark plug from bottom is the one that was covered in fresh oil that looked clean dark caramel color.

 

[UNC017]

Originally Posted By: Luis_G

The last picture is of all 4 spark plugs in order. The 2nd spark plug from bottom is the one that was covered in fresh oil that looked clean dark caramel color.


I assume this engine has the spark plugs at the bottom of "tubes" that extend through the valve cover to the cylinder head. The oil you found on the outside of the plugs is due to slight leakage around those tubes- its completely external to the spark plug, won't get in the combustion chambers (until you remove the plug and it drips in), and is completely harmless. Messy and irritating, but harmless.

 

[Luis_G]

Yeah that's how it is.
Guess it's a valve gasket leak?
Oh well as long as it isn't a problem I will run it as it is.

 

[Gokhan]

Originally Posted By: Gokhan
In my Corolla, which is very similar to his, the source of consumption was valve-stem oil seals. It would consume 2.5 qt per 1,000 mi with Pennzoil Platinum 5w30 and 1 qt per 1,000 mi with Mobil Delvac 1300 Super 15w40. Once I replaced my valve-stem oil seals several years ago, my oil consumption has stopped entirely. Now, I don't see much consumption even with 0W-20.

Since he has a very similar engine that is 16-year-old, his consumption source and possible treatment and cure are more than likely exactly the same.

That's exactly how the threads of my spark plugs looked like in my Corolla before I changed my valve-stem oil seals! So, your valve-stem oil seals have gone bad just like mine. It will keep getting worse as all seals eventually go bad. In your case the oil on the outside is because of the oil coming from the valve cover but the oil on the threads is coming from the valve-stem oil seals. (Oil from the valve cover can't get into the engine through spark plugs and cause oil consumption because the metallic crush gaskets on the plugs are airtight.) Another symptom is that if you stop and idle at a red light with a hot engine for two minutes or more, you will notice oil smoke once you hit the gas and take off. Here are the repair instructions:

Wonders of valve-stem oil seal replacement (link)

For now, use Mobil Delvac 1300 Super 15w40 CJ-4/SM. If you like synthetic, use Mobil 1 0W-40 SN, which has a $12 rebate until the end of October; so, you can get two five-quart jugs and use a $24 rebate. Start topping off with one of these oils and you will see a huge difference in consumption. Since 15w40 is quite a bit thicker than 0W-40, you will see less consumption with it. If you prefer synthetic, go with 0W-40.

The only real cure is the valve-stem oil seal replacement I linked above.