# Nissan Spark Plug Tube Seals Failure



## Nealtw (Jun 22, 2017)

I like it, back yard hackers will be the first to come up with a good answer. 



But how exactly does an oil leak there foul the plugs and damage the cat. 

Or is that just some one pulling the plug and letting in the hole?


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## BigJim (Sep 2, 2008)

Nealtw said:


> I like it, back yard hackers will be the first to come up with a good answer.
> 
> 
> 
> ...


Neal, when the oil fouls the plug, raw gas gets in the converters and will ruin them quickly.


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## Nealtw (Jun 22, 2017)

BigJim said:


> Neal, when the oil fouls the plug, raw gas gets in the converters and will ruin them quickly.


Understood, but how does oil get into the cylinder, the plug is sealed to the head.


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## Brainbucket (Mar 30, 2015)

Found these at rockauto. NAPA has the gasket and tube seal separate. :vs_cool:


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## BigJim (Sep 2, 2008)

Nealtw said:


> Understood, but how does oil get into the cylinder, the plug is sealed to the head.


When the seal goes bad it allows oil to fill the tube the spark plugs are in. The oil floods the plug and the coil won't fire under oil so no fire, raw gas into the converters. 

BB I don't understand that. I have seen the Nissan replacement seals but they aren't replaceable. I may ask to look at those seals when I go to the parts place in a little while. I don't see how they could work.

Here is another video which I think is really the wrong way to do the seals. I don't know what these seals he is using goes to. The number is Fel Pro ES 72481. 

In this video you can see how the orignal seals are in the valve cover. There is a metal lip that goes under the valve cover material, they are made into the cover.

I did see some but they are for valve covers that have the removable oil baffle in them, mine don't have the baffle.


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## Nealtw (Jun 22, 2017)

BigJim said:


> When the seal goes bad it allows oil to fill the tube the spark plugs are in. The oil floods the plug and the coil won't fire under oil so no fire, raw gas into the converters.
> 
> BB I don't understand that. I have seen the Nissan replacement seals but they aren't replaceable. I may ask to look at those seals when I go to the parts place in a little while. I don't see how they could work.
> 
> ...


So that isn't the same a fouled spark plug, the oil is insulation between the coil and the spark plug. That should have a rubber boot around that connection.


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## Brainbucket (Mar 30, 2015)

Some valve covers have 'tabs' that hold the seal in. Just bend them back, r&r seal and bend the tabs back.:vs_cool:


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## BigJim (Sep 2, 2008)

Nealtw said:


> So that isn't the same a fouled spark plug, the oil is insulation between the coil and the spark plug. That should have a rubber boot around that connection.


The coil tube goes around the plug top and around the ceramic, and it is pretty tight. It needs a lubricant so the tube doesn't stick to the plug and get torn when trying to take it off. Even then, the oil seeps into the coil tube and shorts the plug out and it miss fires.

BB I wish this one was like that but it isn't. I think I have come up with a way to replace those non-replaceable seals. If it works I will post some photos of how I did it. The concept I am thinking about is like this: think of a car head light bulb. It has tabs and it is inserted into the socket and turned to tighten it up. That is what I hope to accomplish by modifying the socket and seal. I will post how it turns out.


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## Nealtw (Jun 22, 2017)

BigJim said:


> The coil tube goes around the plug top and around the ceramic, and it is pretty tight. It needs a lubricant so the tube doesn't stick to the plug and get torn when trying to take it off. Even then, the oil seeps into the coil tube and shorts the plug out and it miss fires.
> 
> BB I wish this one was like that but it isn't. I think I have come up with a way to replace those non-replaceable seals. If it works I will post some photos of how I did it. The concept I am thinking about is like this: think of a car head light bulb. It has tabs and it is inserted into the socket and turned to tighten it up. That is what I hope to accomplish by modifying the socket and seal. I will post how it turns out.


They could have used bearing seals


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## BigJim (Sep 2, 2008)

Nealtw said:


> They could have used bearing seals


Neal, I am not surprised at Nissan anymore. I just found out that Nissan merged with Renault back in 1999, that would explain so many Nissans failing way to early by faulty design. Especially the Altima for several years. They had serious issues with the 2.5 engine failing because of the pre-catalytic converter failing because it was made out of cheap junk. 

It would over heat and disintegrate into sand like materials and get sucked back into the engine. This would cause the rings and such to fail way too soon.

Check out how cheap some of the Altimas are right now, that is the reason. Also the Altimas had a power valve that had screws in the butterflys that came loose because they were too cheap to put loctite on the screws. The screws would fall into the cylinders and there goes the engine. This was all in the same years as the pre-cat issue. The really bad part is Nissan would not stand behind their cars. If the engine went down, oh well, you were just on your own. 

The good part is, you could and can buy a good looking Altima and buy one of the Japanese engines. Japan is really strict on their cars. At a certain milage, or age, the engine has to be changed out. Some as low as 35,000 miles. These engines are easy to find and are cheap here in the USA. Japan engines are better than USA made Nissan engines. I could go on and on but you get the picture. Don't buy an Altima with the aluminum intake, get one with the composite intakes, they are good engines. 

The heck of it is, Nissan engines are really good long lasting engines, once the pre-cat and butterfly issue is resolved, if you get one before it is trashed. Altimas after 2007-2010, I think, the best I remember, are really good cars except for their transmissions. Their CVTs are junk IMHO, that is the reason I bought one with a six speed stick. OK I am through now.


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## huesmann (Aug 18, 2011)

Nealtw said:


> So that isn't the same a fouled spark plug, the oil is insulation between the coil and the spark plug. That should have a rubber boot around that connection.


No, a fouled spark plug gets fouled on the _inside_ of the combustion chamber. This is basically fouling on the outside. Think of what would happen if you dumped water on top of the valve cover. Most plug boots don't provide a 100% watertight seal through the valve cover.


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## Nealtw (Jun 22, 2017)

huesmann said:


> No, a fouled spark plug gets fouled on the _inside_ of the combustion chamber. This is basically fouling on the outside. Think of what would happen if you dumped water on top of the valve cover. Most plug boots don't provide a 100% watertight seal through the valve cover.


Engines work out in the rain all the time?


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## huesmann (Aug 18, 2011)

Not all the time. The work out in the rain _some_ of the time.


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## BigJim (Sep 2, 2008)

Well so much for my idea to install the seals like I wanted too. The orignal ones I bought today are nothing like the ones I took out of the valve covers. The ones I took out had a metal lip that looked like a man's hat bream, these don't have that lip. Oh well, back to square one.


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## BigJim (Sep 2, 2008)

Got er back together and it runs great except, I must have a couple vacuum hoes crossed somewhere. Just driving normal it runs perfect, but when trying to accelerate the truck will balk like flipping a switch of. Once I let off and drive normal it is ok again. I replaced all the vacuum hoses as the old ones were crumbling away. There have to be at least 20 different vacuum hoses, if not, sure seems like it. lol

My guess is the hoses that go to the power valve are crossed. The balk is like the power valve is totally dead when accelerating. And now for the search.

I am really overly happy to say that the Spec V is running as good as it gets. It says we are getting 32.4 mpg, that is a pretty good jump from 14-16 mpg. Just checked and the average mpg is supposed to be 21 city / 29 highway. Love it


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## BigJim (Sep 2, 2008)

I found the problem, the power valve butterflies were stuck open. I had to use a screw driver to pry them open. I took the top part of the intake back off and sprayed each pivot point with Deep Creep penetrating oil. I worked them back and forth a bunch of times but they still felt too stiff for the actuator valve to open them. 

I planned to go out there today and take the intake back off and see what was the problem. I gave the butterfly valve a try by hand, just for the heck of it and so help me Hannah, it was freed up and worked like it was supposed too.

We went for a drive for about 30 or so miles, I tried to accelerate quickly several times, worked like a charm. The power valve is working like it is supposed to. I guess the Deep Creep must have soaked in and freed it up. Just hope it keeps working.


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