How bad is it to have oil on your spark plug threads?

[vavavroom]

Weird how it looks like the washer hasn't even been crushed.

Scott

Calibrated elbow failure. Torque wrenches are for amateurs.

 

[Newhart111]

To me there's 0 evidence of that being a valve cover leak. I'd say that cylinder is burning oil, but not to the level where it's fouling the business end of the plug. Does the Toyota 2GR-FE have any history of oil usage? Does yours use oil between changes? Do you have a scope to look into the cylinders and maybe up at the valves?

I’m in the process of changing all the coil packs now and regapping my plugs and re-torquing them.

I do have a scope but I’m a newbie. Can you give me instruction on how I can take a picture of the valves?

I’m pretty sure I’m not burning oil. Would the problem you describe make my threads that wet?

Here is a picture of the new plug that’s been in there only a month -

There is also no oil on the sides of the spark plug tube or at the bottom of the tube indicating a spark plug gasket leak at present.

However on this cylinder (cylinder 2) and cylinder 5 and another (forgot which) I have a little evidence of oil leaking from the spark plug gasket (I posted picture of above).

 

[Newhart111]

Not sure but I think I see a leak from the valve cover gasket because it looks wet around one section with debris stuck to it:

You can see its darker around the gasket area.

 

[Newhart111]

You probably have a valve cover gasket leaking. Keep in mind this will ruin the new plugs and even the coils so your misfires will return if you don't address it.

How does that ruin the coils?

 

[Gus_Mahn]

I’m in the process of changing all the coil packs now and regapping my plugs and re-torquing them.

I do have a scope but I’m a newbie. Can you give me instruction on how I can take a picture of the valves?

I’m pretty sure I’m not burning oil. Would the problem you describe make my threads that wet?

Here is a picture of the new plug that’s been in there only a month -
View attachment 238512

There is also no oil on the sides of the spark plug tube or at the bottom of the tube indicating a spark plug gasket leak at present.

However on this cylinder (cylinder 2) and cylinder 5 and another (forgot which) I have a little evidence of oil leaking from the spark plug gasket (I posted picture of above).

You would need a scope that’s adjustable or has a mirror accessory for the camera to see the valves. Sometimes after a cold soak a valve guide leak will show with a scope that can look up.

Any oil making it into the cylinders would come from the valve guides or piston rings. If you don’t see the level on the dipstick change, I doubt you’d see anything with the scope. Lots of modern cars do seem to be having issues with the piston’s oil rings plugging up the drains and leading to high oil consumption. A lot of people have reduced oil consumption by doing a piston ring flush, and there’s a lot of threads on doing it. I’m not familiar with your engine type, but if it’s a V6, a flush might be challenging. Some also claim to have improved consumption using Valvoline Restore a Protect oil. I’d spend some time searching online about your specific engine and oil usage, but keep in mind you may not really have much of a problem or it may be a slowly progressing problem that might not need to be dealt with.

 

[SC Maintenance]

There was no oil inside the boot. For #5 there was no oil anywhere which seemed like a mystery. So how would the oil get on the threads?

Maybe #2 answers the questions because there was a little evidence of oil:
View attachment 238462
View attachment 238465
View attachment 238466
View attachment 238468
View attachment 238463
It’s surprisingly clean down inside the tube.

So I guess what’s happening is it leaks from the spark plug tube seal, drips down to the plug and then down through the threads and whatever makes it to the electrodes gets burned up. I guess good thing it can make it down the threads, otherwise I would have oil pool up by the boot.

I feel like Toyota owes me and everyone else with this problem because like I mentioned, I believe it was there from when the car was brand new. I know because I’ve seen pictures of people who pulled the plugs on an almost new car and had the same problem on the same cylinders.

Oil isn't coming up from the combustion chamber. I have never seen that, however if it was somehow it would also be covered in carbon from the combustion process.

You likely have a small leak from your spark plug tube seals - its pretty common. Possibly a very small leak dripping down and whicking into the threads, or the plug and tube are getting hot enough for the rest of it to evaporate off. My best guess.

 

[Newhart111]

You would need a scope that’s adjustable or has a mirror accessory for the camera to see the valves. Sometimes after a cold soak a valve guide leak will show with a scope that can look up.

Any oil making it into the cylinders would come from the valve guides or piston rings. If you don’t see the level on the dipstick change, I doubt you’d see anything with the scope. Lots of modern cars do seem to be having issues with the piston’s oil rings plugging up the drains and leading to high oil consumption. A lot of people have reduced oil consumption by doing a piston ring flush, and there’s a lot of threads on doing it. I’m not familiar with your engine type, but if it’s a V6, a flush might be challenging. Some also claim to have improved consumption using Valvoline Restore a Protect oil. I’d spend some time searching online about your specific engine and oil usage, but keep in mind you may not really have much of a problem or it may be a slowly progressing problem that might not need to be dealt with.

Thanks for the reply.

My scope is adjustable but I don’t think I have a mirror attachment to look behind. I’ll have to see what adapters came with it. I can bend it but then it won’t go through the spark plug hole.

 

[Newhart111]

Oil isn't coming up from the combustion chamber. I have never seen that, however if it was somehow it would also be covered in carbon from the combustion process.

You likely have a small leak from your spark plug tube seals - its pretty common. Possibly a very small leak dripping down and whicking into the threads, or the plug and tube are getting hot enough for the rest of it to evaporate off. My best guess.

I think I read another thread once that determined it to be the spark plug seals. Maybe when the engine is cool, there is negative pressure than can suck it onto the threads?

Thanks for your reply.

 

[Astro14]

I think I read another thread once that determined it to be the spark plug seals. Maybe when the engine is cool, there is negative pressure than can suck it onto the threads?

Thanks for your reply.

How would that "sucking" work? If you torqued your plugs properly, then they are sealed against the thousands of PSI of the combustion event. So, why would anything get past them at a few PSI of your "negative pressure", which, I have to say, doesn't exist.

 

[Gus_Mahn]

These 100,000 mile plugs are out of an oil chugging 2017 Audi (1qt in 250miles). The one on the right it very similar to the OP’s picture. There is no evidence of oil dripping down the spark plug well on the plug or gasket. There is more wear and carbon on the plug in the right, but it’s not fouled, and the car ran fine and didn’t smoke. A B-12 ring flush brought the oil burning down to 1500miles per quart. It’s currently running on Valvoline Restore and Protect, but the owner hasn’t brought it back for me to see if there was further improvement.

 

[SC Maintenance]

View attachment 238559
These 100,000 mile plugs are out of an oil chugging 2017 Audi (1qt in 250miles). The one on the right it very similar to the OP’s picture. There is no evidence of oil dripping down the spark plug well on the plug or gasket. There is more wear and carbon on the plug in the right, but it’s not fouled, and the car ran fine and didn’t smoke. A B-12 ring flush brought the oil burning down to 1500miles per quart. It’s currently running on Valvoline Restore and Protect, but the owner hasn’t brought it back for me to see if there was further improvement.

Your one on the right has a heavily fowled electrode and is carboned half way up the threads. I would expect this from an oil burner.

The OP's plug is not fowled, and has wet threads all the way up. My guess is still an oil leak, and the threads got mostly coated on removal.

Of course without knowing how long the plugs were in - its really hard to do anything other than speculate.

 

[Gus_Mahn]

Another thought. Does this car have a PCV valve, and is it near this cylinder on the intake. When was the last time the PCV valve changed? I might have missed how many miles on the engine, and on those spark plugs?

 

[Newhart111]

Your one on the right has a heavily fowled electrode and is carboned half way up the threads. I would expect this from an oil burner.

The OP's plug is not fowled, and has wet threads all the way up. My guess is still an oil leak, and the threads got mostly coated on removal.

Of course without knowing how long the plugs were in - its really hard to do anything other than speculate.

The most recent pic I posted on the plug from cyl 2 is a new spark plug that was in only a month. Also I took time off from work so didn’t drive much. There was no oil in the spark plug tube/well prior to removing it not even a little and none on the sides.

 

[Newhart111]

Another thought. Does this car have a PCV valve, and is it near this cylinder on the intake. When was the last time the PCV valve changed? I might have missed how many miles on the engine, and on those spark plugs?

You just reminded me. I ordered the PCV valve months ago and never picked it up.

Thanks for reminding me.

Cylinders 5 and 6 that have oil on the threads are next to the valve (on the driver side front), but cylinder 2 which also has oil is on the passenger side but also in the front.

PCV valve is next to cyl 6

 

[Astro14]

Its possible. I used a torque wrench (Precision Instruments split beam - supposedly same as Snap-on.)

A Toyota tech on a video said 13 ft-lb. I believe I did more. For now on I think I’ll use the technique to turn additional half turn after it stops.

Not everything you see on YouTube is accurate, or even close to correct.

It’s closer to 18ftlbs.

Under-Torqued Spark Plugs - ClubLexus - Lexus Forum Discussion

GS - 4th Gen (2013-2020) - Under-Torqued Spark Plugs - Going over my car this morning for a basic tune up. I decided to inspect the the spark plugs. Which in turn were replaced at a local Lexus dealer in my area. Apparently within about 500 miles ago according service history online. To my...

www.clublexus.com

The 1/2 turn after it stops applies to new gaskets. Yours have been crushed.

Use torque, not turns, in this case.

 

[LongTime_Lurker]

Also, keep in mind that they may loosen after heat cycling many times (like exhaust manifold bolts sometimes do).

 

[Newhart111]

Not everything you see on YouTube is accurate, or even close to correct.

It’s closer to 18ftlbs.

Under-Torqued Spark Plugs - ClubLexus - Lexus Forum Discussion

GS - 4th Gen (2013-2020) - Under-Torqued Spark Plugs - Going over my car this morning for a basic tune up. I decided to inspect the the spark plugs. Which in turn were replaced at a local Lexus dealer in my area. Apparently within about 500 miles ago according service history online. To my...

www.clublexus.com

The 1/2 turn after it stops applies to new gaskets. Yours have been crushed.

Use torque, not turns, in this case.

First what I did was between 1/8 to 1/4 turn after it stopped with a short ratchet, but then decided to use the torque wrench at 18ft lbs and usually it went a little further.

 

[Newhart111]

Not everything you see on YouTube is accurate, or even close to correct.

It’s closer to 18ftlbs.

I saw the actual Toyota service documentation for my engine and it said 13 ft/lbs. Also the guy in the video is an actual Toyota tech that worked there for many years.



I still used 18 ft/lbs.

I’ve read comments from Toyota/Lexus owners saying they found spark plugs really loose that were previously installed by Toyota/Lexus.

 

[Newhart111]

Btw car is purring now with smooth quiet idle. It even seems perkier now with a better response when hitting the gas.

However now, which is the same as when I changed only one ignition coil at first, I get knocking/rattling sounds when going uphill or hitting the gas enough. If I’m light on the peddle, I don’t get the knocking.

I didn’t have it prior to changing the ignition coil. I also cleaned my throttle body; that shouldn’t cause it. I’m hoping I got some bad gasoline because this would happen if I use regular (which I am not at the moment).

 

[Nesterenko]

Not everything you see on YouTube is accurate, or even close to correct.

It’s closer to 18ftlbs.

Under-Torqued Spark Plugs - ClubLexus - Lexus Forum Discussion

GS - 4th Gen (2013-2020) - Under-Torqued Spark Plugs - Going over my car this morning for a basic tune up. I decided to inspect the the spark plugs. Which in turn were replaced at a local Lexus dealer in my area. Apparently within about 500 miles ago according service history online. To my...

www.clublexus.com

The 1/2 turn after it stops applies to new gaskets. Yours have been crushed.

Use torque, not turns, in this case.

18 ft.lbs would seem to be the ideal torque.