oil consumption stopped due to overfill, safe?

[440Magnum]

Originally Posted By: 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.


No, oil on the hex and insulator part of the spark plugs can't possibly have ANYTHING to do with the valve gaskets (Gokhan is wrong). That's spark-plug tube seals.

 

[Gokhan]

Originally Posted By: 440Magnum
Originally Posted By: 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.

No, oil on the hex and insulator part of the spark plugs can't possibly have ANYTHING to do with the valve gaskets (Gokhan is wrong). That's spark-plug tube seals.

I am not talking about the oil on the outside of the plugs. I am talking about the oil on the threads of the plugs. That oil is seeping through the valve guides because of bad valve-stem oil seals. Oil from the valve cover can't get on the plug threads unless it's seeping through the valve guides. I had exactly the same problem with my Corolla. In my case, the plugs are on the outside of the valve cover; so, there was never oil on the outside of the plugs. However, just like the OP pictured, the plug threads would be wet with oil seeping through the valve guides because of bad valve-stem oil seals when the vehicle was parked or in operation. That was the source of my oil consumption and that's the source of the OP's oil consumption.

 

[440Magnum]

Originally Posted By: Gokhan

I am not talking about the oil on the outside of the plugs. I am talking about the oil on the threads of the plugs. That oil is seeping through the valve guides because of bad valve-stem oil seals. Oil from the valve cover can't get on the plug threads unless it's seeping through the valve guides.


That makes no sense. How can oil get to the spark plug threads EVEN IF IT LEAKS PAST THE GUIDES? That puts oil in the intake or exhaust ports, and eventually into combustion chamber, not on the plug threads unless it just about fills the combustion chamber!

On the other hand, If there's standing oil in the spark plug tube (even just a few drops), it will run down onto the threads as soon as you start backing the plug out of the head and the plug comes out wet with oil. Oil on the threads in this case means nothing. If enough oil were getting into the combustion chambers to push up into the thread space, the tips would be wet with oil and badly fouled with carbon. Actually if that ever happened, I doubt the engine would run because it would be practically hydrolocked with oil.

The plug tips are relatively clean, light, and carbon-free. Its probably a light oil burner ( and that could be either rings or valve stem seals), but not super heavy. I'm not saying that your engine didn't have bad valve stem seals, or that the OP's engine couldn't use a set of valve stem seals... but I am saying that oil on the plug threads does NOT indicate bad valve stem seals. It indicates an external leak onto the back shell of the spark plug (in this case, the plug tube O-rings).

 

[OVERKILL]

Originally Posted By: 440Magnum
Originally Posted By: Gokhan

I am not talking about the oil on the outside of the plugs. I am talking about the oil on the threads of the plugs. That oil is seeping through the valve guides because of bad valve-stem oil seals. Oil from the valve cover can't get on the plug threads unless it's seeping through the valve guides.


That makes no sense. How can oil get to the spark plug threads EVEN IF IT LEAKS PAST THE GUIDES? That puts oil in the intake or exhaust ports, and eventually into combustion chamber, not on the plug threads unless it just about fills the combustion chamber!

On the other hand, If there's standing oil in the spark plug tube (even just a few drops), it will run down onto the threads as soon as you start backing the plug out of the head and the plug comes out wet with oil. Oil on the threads in this case means nothing. If enough oil were getting into the combustion chambers to push up into the thread space, the tips would be wet with oil and badly fouled with carbon. Actually if that ever happened, I doubt the engine would run because it would be practically hydrolocked with oil.

The plug tips are relatively clean, light, and carbon-free. Its probably a light oil burner ( and that could be either rings or valve stem seals), but not super heavy. I'm not saying that your engine didn't have bad valve stem seals, or that the OP's engine couldn't use a set of valve stem seals... but I am saying that oil on the plug threads does NOT indicate bad valve stem seals. It indicates an external leak onto the back shell of the spark plug (in this case, the plug tube O-rings).


This +1. Oil on the plug threads is oil that has either wicked its way down between the plug/head interface or, if it is fresh, from oil standing in the plug tubes. Both are indicative of a plug tube seal leak/VCG issue.

Oil getting by the valve guides will be burned. This usually results in a puff of blue in the AM and, depending on the severity of the issue, white ash deposits on the plugs.

 

[Gokhan]

440Magnum and OVERKILL: You are talking based on pure speculation, and I am talking based on actual experience on a Corolla engine!

If what you were saying was true, why would my plug threads would be covered in oil despite the plugs being located outside the engine and there being no oil on outside the plugs? I saw this every year when I replaced the plugs. After I replaced the valve-stem oil seals, I've never seen it.

Google about this. It's a very common symptom of leaking valve-stem oil seals in some engines. Seals leak even when the engine is parked and cold, and the oil doesn't get a chance to burn.

 

[OVERKILL]

Originally Posted By: Gokhan
440Magnum and OVERKILL: You are talking based on pure speculation, and I am talking based on actual experience on a Corolla engine!


Actually, no I'm not. This topic was covered in pretty solid detail when I took automotive mechanics. I also used to be quite active in the Mustang/Hot Rod scene and have torn down and been involved in the tearing down of quite a few engines.

Originally Posted By: Gokhan
If what you were saying was true, why would my plug threads would be covered in oil despite the plugs being located outside the engine and there being no oil on outside the plugs? I saw this every year when I replaced the plugs. After I replaced the valve-stem oil seals, I've never seen it.


Because your valve cover gasket was seeping/leaking. This is the same reason I had oil traces down the plug wells and on the threads of one of my 302's (which had healthy valve seals) and why it stopped when I replaced the valve cover gaskets. You removed the valve cover and gasket to replace the seals.

Originally Posted By: Gokhan
Google about this. It's a very common symptom of leaking valve-stem oil seals in some engines. Seals leak even when the engine is parked and cold and the oil doesn't get a chance to burn.


What leaks is only the little amount of oil left in the head. Which then gets down and sits on the valve if it is closed or sits on the piston crown. It is blown out the exhaust/burned as soon as you fire the engine up. Unless you have a horizontally opposed engine, the oil isn't magically going to go down the valve seal, across the valve, and then work its way UP to the plug.

If your theory was sound, every two stroke, which burns oil, would have oily plug threads. But they don't. The only time you get oil on the plug threads of a 2-stroke is when the plug or coil dies and nothing is combusting. You then end up with a wet plug with wet threads, that look like this:

Normal, oil burning 2-stroke plug on the left. Fouled plug with gas/oil wet threads on the right. The same will happen with a 4-stroke engine if the oil leak is bad enough that the plug gets fouled. THEN the threads and plug face will be wet with oil, because it can't be burned off and it just gets flung all over the cylinder and the compression forces it to creep up the plug threads. They look like this:

I've torn down engines with baffed valve seals (SBC) that had visible white deposits all over the plugs (burned oil). Yet they had no oil on the threads. We've had numerous antique boats that also burned on start-up that had dry plug threads.

The plugs from a serious oil burner generally look like this:

The plugs from an engine with a valve cover leak look like this (this is an SBC):

You can see the electrode area is clean because the oil is not being burned, it is instead coming down the threads.

For a dual overhead cam engine or engine with centrally placed plugs the cause of wet threads is almost always a leaking o-ring or valve cover gasket. The only exception is that if the plug is oil fouled to the point of failure in which case fuel and oil can be pushed up the threads. But this accompanies a fouled plug. If you have a normal looking plug and wet threads, the oil is not coming from guides or rings.

 

[Gokhan]

OVERKILL, you seem to be a great theoretician but I have done the actual experiment with an actual Corolla engine -- many times.

No, my valve-cover gasket has never leaked! I always keep it well-maintained.

No, I've never had oil on the outside of spark plugs.

However, I still had oil on the threads of the plugs everytime I replaced them, and I used to do it every year. And once I replaced the valve-stem oil seals, I've never had any oil on the threads. I don't know why you still have doubts about this.

 

[Garak]

Well, you should be able to conduct a very cheap, easy experiment then, particularly if you intend to do something about the stem seals. Replace the valve cover gasket itself first, since that should be about a $5 part and a few minutes of labour, assuming the Corolla isn't a disaster to work on, and given the vintage, it shouldn't be. Clean up all your plugs and plug wells at the same time. Drive a few weeks, and update us, before you deal with the stem seals. See if things are still clean down there before you do the stem seals.

 

[Luis_G]

Sounds smart Garak. I will do that and post back.

 

[Garak]

I just hope I didn't open a can of worms.

With my old Audi 200, it was, literally a job that took less than 30 minutes, and the valve cover gasket was $17, including shipping from the States. Of course, it didn't help the leaks that the valve cover nuts were only finger tight, but it did help the repair time.

 

[OVERKILL]

Originally Posted By: Gokhan
OVERKILL, you seem to be a great theoretician but I have done the actual experiment with an actual Corolla engine -- many times.


You have fantastic selective reading skills as apparently you missed the part of my post where I noted actual experience with all of the scenarios on multiple engines which caries significantly more weight than your single example with one car.

And a valve cover gasket leaking has nothing to do with how well you maintain it. Seeps/leaks happen. This is the usual cause for wet threads, either through the plug well for a centrally located plug or down the head surface for externally located plugs.

Did you or did you not replace the valve cover gasket when you replaced the valve stem oil seals? Did you or did you not have to remove the valve cover? Of course you did. Had you, at any point prior, replaced the valve cover gasket or removed the valve cover?

The reason that your position on this is being questioned not only by me, but by other people is that in order for oil to get on those threads, it would need to be in a quantity high enough to foul the plug, otherwise it would just burn. The only alternative method I can think of would involve the location of the plug relative to the intake or exhaust valve being placed in such a way that the oil seeping down the valve stem and across the open valve is dripping directly on the threads of the plug that protrude in the chamber allowing it to wick up the plug threads while the engine was OFF. Because running, it is going to be burned.

Oil is heavy. it is going to go to the lowest point, which is either on the top of the valve if it is closed or onto the piston top if it is open (unless the engine is horizontally opposed). The spark plug is never the lowest point. So the oil has no way to get on the threads unless it is being tossed there by the piston, which won't happen if combustion events are happening. This then requires a fouled plug. Which is the ONLY time I've seen oil on the threads of a plug that wasn't due to a valve cover or o-ring leak.

Your theory as to the seals being the cause doesn't make sense unless your engine is specifically setup in such a way that the oil is able to get on the plug threads when the engine is OFF. I'm not saying this is impossible, it most certainly isn't. But it would be unusual and very far from typical.

 

[OVERKILL]

Originally Posted By: 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.

Those plugs are wet right up the bodies, so you definitely have a VCG/O-ring leak.

 

[440Magnum]

Originally Posted By: Gokhan
OVERKILL, you seem to be a great theoretician but I have done the actual experiment with an actual Corolla engine -- many times.

No, my valve-cover gasket has never leaked! I always keep it well-maintained.

No, I've never had oil on the outside of spark plugs.

However, I still had oil on the threads of the plugs everytime I replaced them, and I used to do it every year. And once I replaced the valve-stem oil seals, I've never had any oil on the threads. I don't know why you still have doubts about this.


Because whatever the problem was that was getting your plug threads wet, it was NOT the valve stem seals, because That. Is. Impossible! End of story.

"Theory" doesn't enter into it, there simply exists NO path from the valve stems to the plug threads which would wet the plug threads without massively fouling the plug.

To replace your valve stem seals, you HAD to remove the valve cover and spark plug tubes. The logical explanation is that when you re-installed those, it fixed the leak that was getting your plugs wet while the new valve stem seals fixed the oil consumption.

Correlation <> Causation applies here.

 

[OVERKILL]

Gokhan:

I just looked up what I believe to be the engine from your car. I see that the valves cant toward the back (intake/exhaust) of the engine. The plug comes in directly between the valves from the front. Does this engine also happen to lean forward by chance in the vehicle or is it straight up and down?

If it leans forward, I could see how oil running down the stem could come off the valve into the port and/or chamber and then run onto the plug threads while the engine is off. But this would require two things:

A: Really baffed seals (which you said you had)
B: The engine angled in such a way to make this possible.

Here are a couple of pics I found showing what I mean:

Now, compare the plug/valve location to something like an SBC:

On a 2-valve cross-flow head, like the SBC above, the exhaust is usually "downhill" so a leak on the exhaust stem seal either goes out the exhaust port or down the valve into the cylinder. However this Toyota head head is not a cross-flow design; in the case of this particular head, the exhaust is uphill. So if the exhaust stem seals were leaking (and this could probably go for the intake seals too) it could drip onto the back of the exhaust runner and migrate through an open valve onto the chamber surface and travel that very short distance downhill (if the engine is angled forward) onto the plug threads and then wick its way up. This is the only way I can see the oil getting there that doesn't involve the usual culprit of an external leak

On the other hand, the OP's 1ZZ-FE has a cross-flow head design with a pent-roof chamber and centrally located spark plug. Any oil going by the valve stem seals in this design would end up either in the runners (and if enough of it, down the wall) or down the valve stem, across the back of the valve and into the cylinder. It would never end up on the combustion chamber surface of the head anywhere near the plug threads.

A pic of his head in comparison:

 

[Gokhan]

440Magnum, I don't have plug tubes. Plugs are located on the outside. There was never any oil leak from the valve-cover gasket and the outsides of the plugs were always completely dry. This was also no one-time observation. So, your speculation is wrong.

OVERKILL, yes, that looks like my engine. Yes, the engine angle changes when you put the car into gear. It rocks back and forth when you put into forward and reverse. Yes, the valve-stem oil seals were entirely worn, like having no seals at all.

Regardless of what the cause of wet plug threads on OP's car, his valve-stem oil seals are more than likely the source of his oil consumption. If it was the rings, he would see loss in engine power and fuel economy as well. Toyota engines are well-built and rings don't go bad easily. He can do a simple compression test to find out whether it's the valve-stem oil seals or rings.

 

[OVERKILL]

Originally Posted By: Gokhan

OVERKILL, yes, that looks like my engine. Yes, the engine angle changes when you put the car into gear. It rocks back and forth when you put into forward and reverse. Yes, the valve-stem oil seals were entirely worn, like having no seals at all.


Does the engine, when sitting, have a forward lean to it by chance?

Originally Posted By: Gokhan
Regardless of what the cause of wet plug threads on OP's car, his valve-stem oil seals are more than likely the source of his oil consumption. If it was the rings, he would see loss in engine power and fuel economy as well. Toyota engines are well-built and rings don't go bad easily. He can do a simple compression test to find out whether it's the valve-stem oil seals or rings.


The wet plugs are from his leaking gaskets, that's pretty much a guarantee based on the pictures he's posted.

Regarding oil consumption, there's an issue with the 1ZZ-FE due to ring sticking that results in this from what I recall. Here's a thread on it covering the fix:

http://www.toyotanation.com/forum/131-8th-generation-1998-2002/402362-diy-oil-consumption-fix.html

 

[Gokhan]

Originally Posted By: OVERKILL
Originally Posted By: Gokhan

OVERKILL, yes, that looks like my engine. Yes, the engine angle changes when you put the car into gear. It rocks back and forth when you put into forward and reverse. Yes, the valve-stem oil seals were entirely worn, like having no seals at all.

Does the engine, when sitting, have a forward lean to it by chance?

I would have to look and try to estimate the angle. It's possible according to this timing-belt-cover drawing, which is on the passenger side (right side):

Originally Posted By: OVERKILL
Originally Posted By: Gokhan
Regardless of what the cause of wet plug threads on OP's car, his valve-stem oil seals are more than likely the source of his oil consumption. If it was the rings, he would see loss in engine power and fuel economy as well. Toyota engines are well-built and rings don't go bad easily. He can do a simple compression test to find out whether it's the valve-stem oil seals or rings.

The wet plugs are from his leaking gaskets, that's pretty much a guarantee based on the pictures he's posted.

Regarding oil consumption, there's an issue with the 1ZZ-FE due to ring sticking that results in this from what I recall. Here's a thread on it covering the fix:

http://www.toyotanation.com/forum/131-8th-generation-1998-2002/402362-diy-oil-consumption-fix.html

They call a complete engine overhaul a "fix"?!!!

I doubt the OP wants to do a complete engine overhaul. I would recommend him to switch to Mobil 1 0W-40 SN first and see how much it helps with his consumption. If this doesn't reduce his consumption to a satisfactory level, he can later do some compression test and decide if it would help to replace the valve-stem oil seals and if he is willing to undertake the task.

And, yes, Toyota doesn't build these engines as well as it did in the 1980s.

 

[Luis_G]

Originally Posted By: Garak
I just hope I didn't open a can of worms.

With my old Audi 200, it was, literally a job that took less than 30 minutes, and the valve cover gasket was $17, including shipping from the States. Of course, it didn't help the leaks that the valve cover nuts were only finger tight, but it did help the repair time.


It's very easy to do the valve gasket. Going to replace that first because it is cheap, and it's a possibility.
In fact it makes sense. About 1 year ago when I took my car to a shop because of some oil stains on the motor. They told me it looked like oil was leaking from the valve cover area. They recommended replacing the seal. When I took it apart myself the seal had been pinched, and it had a oil streak that lead to the bigger oil stain on the motor. I fixed it. No oil stains since however it may be possible I didn't do a good job seating the seal near the spark plugs!

Once inside I can see if oil made it inside the spark plugs. This time I will just replace the gasket seal, and test again.
The valve stems however are a different thing and takes a while longer. Never done it but looks like I can do it just need a weekend for it.

 

[Gokhan]

Fel-Pro valve-cover-gasket sets are great and they are about $10 or less, depending on what is included with them.

 

[Garak]

Originally Posted By: Luis_G
It's very easy to do the valve gasket. Going to replace that first because it is cheap, and it's a possibility.

Exactly. It certainly won't hurt to try!