Oil in spark plug wells

[drewdat]

So I recently picked up a 2010 lc from out of town. I had a Toyota dealer do a pre purchase inspection and they recommend replacing the spark plugs. After driving it for a few days and noticing the MPG averaging 13ish I decided to try and tackle changing the spark plugs myself. Unfotunately I found the rear two spark plug wells on the passenger side were full of oil. I could see oil on the outside of the valve cover too. I also noticed a little bit of oil on one of the spark plugs on the driver's side. I'm guessing I need to replace the valve cover gasket and spark plug seals. The LC has 161,000 miles on it.

Anyone ever tackle this? The only write up I could find was on a Tundra forum.

Changing Valve Cover Gaskets

 

[TonyP]

Haven't done it on a LC but many other vehicles. It's a simple process; remove old, install new. Here are the torques and sequences.

 

[Taco2Cruiser]

It’s pretty simple. Just take your time. Word or the wise though, the spark plug seals are very robust and a different material than the valve cover gaskets. If you replace both those seals and still have oil in the wells. Then it’s the bottom of the well that’s giving you problems. The bottom of the well is hammered in with sealant. To replace that, you’ll have to remove the entire valve train to get to them. Not trying to scare you, just letting you know that there is more to oil in the wells than the oring at the top.

 

[UCrazyKid]

In the Lexus ISF world (my other car) it is common for the that V8 to get oil there as well on the back plugs by the fire wall. It seems to be a common issue and many find the seals are fine and that it is a oil fuel mix that works it’s way up the plug threads over time.

You might want to clean it up, place the new plugs and check them again in a month and see how much accumulation you get before pulling the covers.

 

[drewdat]

Any opinions on whether I should get an aftermarket vs OEM gaskets for this? The cost isn't huge (@ $95 OEM vs $35 Aftermarket) but if there isn't a difference, aftermarket is easier to get my hands on.

 

[afgman786]

Posting here hoping this is a more appropriate thread...

Upon startup today had a rough starting sound, as if fan was hitting something or a part wasn't turning. Checked under the engine, fan is spinning freely along with the belt. Noticed smoke from right wheel well, smoke smells like oil..
Checked my oil after getting back home. Oil level is good.

 

[ionyota]

So is there some expectation that there’s going to be oil on the plugs?

I recently came across an ‘08 with the 5.7 that had oil on one of the plugs. Pretty slight amount of oil. Engine has 150k+. Owner of the rig indicates that Toyota said it isn’t a big deal and nothing to worry about. That strikes me as odd, but maybe it isn’t a big deal?

 

[Taco2Cruiser]

So is there some expectation that there’s going to be oil on the plugs?

I recently came across an ‘08 with the 5.7 that had oil on one of the plugs. Pretty slight amount of oil. Engine has 150k+. Owner of the rig indicates that Toyota said it isn’t a big deal and nothing to worry about. That strikes me as odd, but maybe it isn’t a big deal?

Honestly, it really isn’t. But it bothers the living crap out of me.

Sometimes people get lucky, and it is the seal at the top of the spark plug tube that is in the valve cover, which is easy to replace. Sometime people don’t get lucky, and the issue is the FIPG at the bottom of the spark tube has failed.

I had the issue where my FPIG failed on 5 cylinders, so I found a way to remove the spark tubes from the block, then I could clean and re-seal the tube into the block. Either way, it can absolutely be fixed to how it was at the factory (maybe better seeing as how it’s a common issue in 5.7s). But like all things, it depends on how much you want to deal with it.

 

[ionyota]

Honestly, it really isn’t. But it bothers the living crap out of me.

Sometimes people get lucky, and it is the seal at the top of the spark plug tube that is in the valve cover, which is easy to replace. Sometime people don’t get lucky, and the issue is the FIPG at the bottom of the spark tube has failed.

I had the issue where my FPIG failed on 5 cylinders, so I found a way to remove the spark tubes from the block, then I could clean and re-seal the tube into the block. Either way, it can absolutely be fixed to how it was at the factory (maybe better seeing as how it’s a common issue in 5.7s). But like all things, it depends on how much you want to deal with it.

Thanks. What exactly is the seal at the top of the spark plug in the valve cover? Is something like a rubber o-ring that can be easily removed and replaced?

 

[Taco2Cruiser]

Thanks. What exactly is the seal at the top of the spark plug in the valve cover? Is something like a rubber o-ring that can be easily removed and replaced?

Pretty much. It’s round and needs to be hammered into the valve cover (that’s what it says in the FSM). So can easily be done in a garage. Seals are like $5-8 for one if I remember correctly. The seal just fits around the spark plug tube, and that’s what keeps oil from coming through the top, and dripping down to the plug. But again, I know plenty of people who change those seals, and still have oil in their tubes, and that means it’s from the sealant at the bottom.

 

[alta]

I had the issue where my FPIG failed on 5 cylinders, so I found a way to remove the spark tubes from the block, then I could clean and re-seal the tube into the block. Either way, it can absolutely be fixed to how it was at the factory (maybe better seeing as how it’s a common issue in 5.7s). But like all things, it depends on how much you want to deal with it.

@Taco2Cruiser My rig is currently in getting the spark plug tube seals done. I have oil in almost all of my tubes, so assuming the worst. Would you mind elaborating on what you did to fix the FPIG failure? Thanks in advance!

 

[2001LC]

In the Lexus ISF world (my other car) it is common for the that V8 to get oil there as well on the back plugs by the fire wall. It seems to be a common issue and many find the seals are fine and that it is a oil fuel mix that works it’s way up the plug threads over time.

You might want to clean it up, place the new plugs and check them again in a month and see how much accumulation you get before pulling the covers.

Honestly, it really isn’t. But it bothers the living crap out of me.

Sometimes people get lucky, and it is the seal at the top of the spark plug tube that is in the valve cover, which is easy to replace. Sometime people don’t get lucky, and the issue is the FIPG at the bottom of the spark tube has failed.

I had the issue where my FPIG failed on 5 cylinders, so I found a way to remove the spark tubes from the block, then I could clean and re-seal the tube into the block. Either way, it can absolutely be fixed to how it was at the factory (maybe better seeing as how it’s a common issue in 5.7s). But like all things, it depends on how much you want to deal with it.

Are you guys or anyone that cares to respond. Finding the spark plugs lose (walking out.)?

In these walk outs, oil will gets on lower end of spark plug. But typically looks like thick gunk and not dripping wet. This is the combustion gasses escape past threads. Early stage they sung when hot. Later stage they don't sung enough to stop gasses from escaping when hot. Final stage plug blows out the heads, taking out heads threads when they do.

This is a big deal in the 4.7L with Denso. Many have neglected or just don'y know to R&R spark plugs or re-torque. Seems to be issue more with Denso than NGK, but this I'm not sure of. As I don't see many with NGK.

I find this so often in the 100 series:

Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!

TICK TICK TICK POP POP POP is a ticking time bomb, often mistaken as exhaust manifold crack or gasket leak leak. ALERT, ALERT, ALERT: Spark plugs are working themselves loose. "Walking Out" Then blowing out of head, taking their female threads of head with them! Very damaging! You think TICK...

forum.ih8mud.com

 

[04UZJ100]

Are you guys or anyone that cares to respond. Finding the spark plugs lose (walking out.)?

In these walk outs, oil will gets on lower end of spark plug. But typically looks like thick gunk and not dripping wet. This is the combustion gasses escape past threads. Early stage they sung when hot. Later stage they don't sung enough to stop gasses from escaping when hot. Final stage plug blows out the heads, taking out heads threads when they do.

This is a big deal in the 4.7L with Denso. Many have neglected or just don'y know to R&R spark plugs or re-torque. Seems to be issue more with Denso than NGK, but this I'm not sure of. As I don't see many with NGK.

I find this so often in the 100 series:

Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!

TICK TICK TICK POP POP POP is a ticking time bomb, often mistaken as exhaust manifold crack or gasket leak leak. ALERT, ALERT, ALERT: Spark plugs are working themselves loose. "Walking Out" Then blowing out of head, taking their female threads of head with them! Very damaging! You think TICK...

forum.ih8mud.com

What do you re-torque to? 15ft-lb?

 

[2001LC]

18ft-lbf with digital torque wrench, for better accuracy.

With 4.7L (100 series, FSM is 13ft-lbf) I've been using Denso torque guidelines range, and picked 18ft.lbf for 14mm spark plug in aluminium heads.

But it's to soon to know, if this higher torque does much good, in stopping walk-out. I need to have some back in shop, to check at 30K, 60K, 90K, 120K, etc, To see if this stop the walk-out, slows or waste of time. But even miles is not a great guide. It's really based on warm-up and cool-down cycles (expansion & contraction) IMHO.

I notice with a Denso new plugs which has a fresh crush washer. As I reach ~17.5 ft-lbf with digital torque wrench. The plugs turns or slips just a tad, torque drops back a bit. I then continue to 18ft-lbf which feels very solid.

In 5.7L (200 series). I'd use 18ft-lbf also.

https://www.densoautoparts.com/spark-plug-installation

Here's a picture of set of replacement plugs (~50K on them) someone installed. Then ~5K ago, a well know Cruiser shop in CA, replaced head cover gaskets and tube seals. #1 tube seal apparently got hung up, cutting it and coming out top of cover leaking badly. #1 Tube was full of oil.

#1 (upper left corner) in picture. You can see how much oil after lightly wiping, still remained and soaking the paper sack. Coil is sitting to side (out of picture in pan) with oil dipping off.

Look at #5 (3rd down on left). That was a loose (walking out) plugs. The gunk on it's nut, is from combustion gasses blowing past the thread.

Coils likely switch around during head gasket job, by other shop. So likely #8 (lower right) coil was in different cylinder. Look how dark and burnt looking #8 coil is. That also is damage form hot combustion gasses passing threads. The brown coils boots, are also combustion gasses damage.

If engine running rich and plugs removed or after raising RPMs for 5 mins. Plugs removed that are wet, are sign of possible oil ring leakage/seepage.

When oil gets in spark plug tube, plug is dripping wet Note: if plugs loose, oil drips into combustion camber. S that oil will just collect there. The coil, if leak went bad or continued long enough, is also dipping wet. See how much oil dipped on brown sake from #1

Often times oil comes out the tube and covers head cover in that area. Combustion gasses will also, but typically not as wetting to head cover. Before remove plug, we see puddle of oil in tube, with tube seal leak.

Plug thread can be wet for other reason also. Like loose and running rich, oil ring, PCV clog, etc..

 

[Taco2Cruiser]

I’ve yet to find a loose spark plug from a tube filled with oil. From only what I’ve seen, this is simply factory assembled components FIPG failing. With is common with the 5.7.

Of the ones I’ve re sealed, all but two of the customers knew of the oil in there. And they have all told me the same story about how they checked plugs fro being tight and then paid someone/themselves replaced the tube seals in the valve cover gasket. PCV is always good to check, and I know of a couple guys who have had a stick Valve, but the overwhelming amount of them I see, the PCV is not the issue. It’s just super simple and common to say, “check the PCV.” I spend a lot of time over a Bob is the oil guy, and it like a script over there. Not complaining, kinda rambling, but I guess just assuring that other components where checked.

I don’t want to open a can of horms, but I don’t feel the 200 is as bullet proof as we like to imagine it is. These things are defiantly up there in durability, but they still have plenty of components that need replacement sooner than I think a truck of this caliper should.

 

[04UZJ100]

I’ve yet to find a loose spark plug from a tube filled with oil. From only what I’ve seen, this is simply factory assembled components FIPG failing. With is common with the 5.7.

Of the ones I’ve re sealed, all but two of the customers knew of the oil in there. And they have all told me the same story about how they checked plugs fro being tight and then paid someone/themselves replaced the tube seals in the valve cover gasket. PCV is always good to check, and I know of a couple guys who have had a stick Valve, but the overwhelming amount of them I see, the PCV is not the issue. It’s just super simple and common to say, “check the PCV.” I spend a lot of time over a Bob is the oil guy, and it like a script over there. Not complaining, kinda rambling, but I guess just assuring that other components where checked.

I don’t want to open a can of horms, but I don’t feel the 200 is as bullet proof as we like to imagine it is. These things are defiantly up there in durability, but they still have plenty of components that need replacement sooner than I think a truck of this caliper should.

Sounds like it’s a non issue though regardless of where the oil leak comes from? Just a matter of if you want to live with it or not.

I still believe the 2UZ has far less systemic issues than the 3UR does.

 

[2001LC]

I’ve yet to find a loose spark plug from a tube filled with oil. From only what I’ve seen, this is simply factory assembled components FIPG failing. With is common with the 5.7.

Of the ones I’ve re sealed, all but two of the customers knew of the oil in there. And they have all told me the same story about how they checked plugs fro being tight and then paid someone/themselves replaced the tube seals in the valve cover gasket. PCV is always good to check, and I know of a couple guys who have had a stick Valve, but the overwhelming amount of them I see, the PCV is not the issue. It’s just super simple and common to say, “check the PCV.” I spend a lot of time over a Bob is the oil guy, and it like a script over there. Not complaining, kinda rambling, but I guess just assuring that other components where checked.

I don’t want to open a can of horms, but I don’t feel the 200 is as bullet proof as we like to imagine it is. These things are defiantly up there in durability, but they still have plenty of components that need replacement sooner than I think a truck of this caliper should.

Thanks @Taco2Cruiser So you're say many if not most of these. Oil leak, is FIPG at bottom of the pressed in spark plug tube.

How are you repairing? Have you a thread on this?

I just spoke with a 20 year man at Toyota. He said pull head and press in. WTF. Got to be better way???

200 series I'm going to start on today. I've picture of spark plug still in socket. Socket has oil on it from bottom up about 1". That is from oil in the #7 tube.

Now we need to know, from where is oil coming. Is it the tube seal in the valve cover. Or did tube come loose and we've a leak from bottom up.

I did notice some dust sticking to oily surface around #5 #7 coil seals.

So I'll study the tube seal as I pull coils. Hope to see oil on the seal, as clue oil coming from top. If seal dry, it makes a case oil is bottom up.

Oil on spark plug socket from bottom up about 1". Indicate oil in tube #7

Head cover dust stuck to oil around #5 & #7 coils. All others dry.

I'll take some more pictures once coils out.

Just to be clear:
Spark plug walking-out is a big issue in all the 4.7L 2UZ. It has nothing to do with oil in the tubes.

As far as 4.7L 2UZ value cover gasket and their spark plug tubes seal. I've never replaced one. I've re-torque the bolts to the valve cover, which I always find need 1/4 to full turn, to hit spec of 53IN-lbf. I've stop the leak/weep in ever one to date, just by re-torquing.

 

[04UZJ100]

Thanks @Taco2Cruiser So you're say many if not most of these. Oil leak, is FIPG at bottom of the pressed in spark plug tube.

How are you repairing? Have you a thread on this?

I just spoke with a 20 year man at Toyota. He said pull head and press in. WTF. Got to be better way???

200 series I'm going to start on today. I've picture of spark plug still in socket. Socket has oil on it from bottom up about 1". That is from oil in the #7 tube.

Now we need to know, from where is oil coming. Is it the tube seal in the valve cover. Or did tube come loose and we've a leak from bottom up.

I did notice some dust sticking to oily surface around #5 #7 coil seals.

So I'll study the tube seal as I pull coils. Hope to see oil on the seal, as clue oil coming from top. If seal dry, it makes a case oil is bottom up.

Oil on spark plug socket from bottom up about 1". Indicate oil in tube #7
View attachment 2680320
Head cover dust stuck to oil around #5 & #7 coils. All others dry.
View attachment 2680334View attachment 2680333

I'll take some more pictures once coils out.

Just to be clear:
Spark plug walking-out is a big issue in all the 4.7L 2UZ. It has nothing to do with oil in the tubes.

As far as 4.7L 2UZ value cover gasket and their spark plug tubes seal. I've never replaced one. I've re-torque the bolts to the valve cover, which I always find need 1/4 to full turn, to hit spec of 53IN-lbf. I've stop the leak/weep in ever one to date, just by re-torquing.

Looking forward to more pictures and thoughts from your extensive experience.

So, based on that picture, is the entire tube filled with oil? Once the plug is removed - does this oil freely drain into the combustion chamber? I assume it can bring along any debris in there along with it? How is it ejected once in the combustion chamber - out an exhaust stroke?

 

[2001LC]

Looking forward to more pictures and thoughts from your extensive experience.

So, based on that picture, is the entire tube filled with oil? Once the plug is removed - does this oil freely drain into the combustion chamber? I assume it can bring along any debris in there along with it? How is it ejected once in the combustion chamber - out an exhaust stroke?

Based on picture given to me when plugs removed (see above). No tubes were not filled.

Any oil remaining in tube when plugs remove, will fill cylinder. Small amount of oil will not hurt the cylinders. But there is two concerns here:
1) If to much oil fills cylinder, it's possible to hydro-lock the cylinder. By just letting engine rest, oil will find its way through the piston rings into crank case, in a cold engine faster than hot. A tube fulled to top, may be to much oil. So soaking up before pulling plug, is one solution.

In the 4.7 I just did find tube filled with oil and pulled plug for compression test. I needed to crank while engine still hot for the test. So I use a paper shop towel, absorbed as much oil as I could, before pulling plug. Note: Compression test is done dry first, then wet (add oil to cylinder). Wet we add ~1oz oil.

2) Contaminants in oil (dust sand) getting into cylinder.
If coil has a good rubber seal on between it and head cover. The tubes remain clean of dust & sand. Provided care is take to clean top of engine beforehand. This is one of the reasons, I like power washing engine beforehand. I also use HP shop air, blow away dust/sand/etc. If I was to see concerning signs of contaminates under coil seal or in tube. A shop vac could be used to suck out oil & contaminates. I suppose one could spray even something like Sea-foam fogger into tube, puddling, then vac out again. Fluid will help carry away contaminates.

 

[2001LC]

I'm really like some help here @Taco2Cruiser or whomever can give advise, or just link me to a thread on re-seating (FIPG & press) the spark plug tube into head.

I'm R&R radiator, water pump, thermostat and more on this one now. Which iron bumper and Slee battery tray are slowing me down. So I only managed to pull the 2 coils, from #5 & #7 cylinders. Which are only ones I saw signs of oil on head covers (pictured above)

I'm see encouraging signs, in that it appears tube seals are leaking. I only see about a table spoon of oil in tubes. Coils seal are okay but not great. As I see one tiny drop of water. This is from power washing.

So on this 5.7L, I'm inclined to just R&R head cover gaskets & seals. But I would like to learn if there is indeed, a way to re seat tubes into head, without removing heads. But for 1 tablespoon of oil in tubes in between oil changes. I did live with it, rather than pulling a head. One could clean out oil each 5K or so, and replace coil boots as needed.

So here some pictures of #5 & #7.
#5 is easy to see it only has little oil in bottom of tube. likely less than tablespoon.

#7 picture not as clear, but I'd guess about 1 tablespoon. This is worst one so far, and seal was wettest.

Coil of #7 had oil top down on underside. Top side appeared dry.

I'll try and get some pictures while doing the job.