Leaking Oil Seals - Spark Plug Tubes

[lomita]

Went to look at the plugs today and change them out in hopes of addressing the low fuel mileage of 12.5 mpg around town.

The MAF sensor was clean as a whistle; the butterfly and throat of the throttle body had some black oily film inside. Cleaned it out. Look ma, no cables! It's an all electric throttle!

Spark plug tubes all had oil residue within them.

Plug #6 was wet on the outside at the base of it.

Anyone seen this before and had to change the spark plug tube oil seals?

Looks like the intake manifold, throttle body, and valve covers will have to come off!

[rn79870]

I'm bumping this, can anyone help?

[Q451990]

I don't know if it's true or not, but I have heard that the G's spark plug tube gaskets (not sure if that's the technical name) are built in to the cover - and that this can get a little costly.... not sure though.

Heath

[telcoman]

Went to look at the plugs today and change them out in hopes of addressing the low fuel mileage of 12.5 mpg around town.

The MAF sensor was clean as a whistle; the butterfly and throat of the throttle body had some black oily film inside. Cleaned it out. Look ma, no cables! It's an all electric throttle!

Spark plug tubes all had oil residue within them.

Plug #6 was wet on the outside at the base of it.

Anyone seen this before and had to change the spark plug tube oil seals?

Looks like the intake manifold, throttle body, and valve covers will have to come off!

lomita:

Welcome to NICO

The year of your vehicle is not in your signature, however, INMHO if you are doing your own work on your vehicle yourself, it may pay for you to obtain the shop manual? You can do a search on this site to find your year and section. You may want to read up on changing spark plugs?

Telcoman

[g35sedanlover]

same problem, need help!

[lomita]

Follow up confirmation, no seals available for purchase and installation from the dealer, must replace entire valve cover! $221 each from dealer retail.

Alternate fix has been suggested by another member, pull the valve cover, clean, and RTV around the seal.

You know the story about the farmer and his mule? He's in the field plowing and the mule tries to swat him with his tail. The farmer says, that's one. A while later the mule turns and tries to bite him. The farmer says, that's two. Then the mule tries to kick the farmer. The farmer says, that's three, pulls out his gun and shoots the mule. He comes home late and walks in the door. His wife barks, you're late. The farmer replies, that's one!

For our G35, low gas mileage, that's one.

For the spark plug tubes leaking oil on the plugs at 21,000 miles, that's two.

[Sentientbydesign]

Did you think you were buying a Toyota?

You've got a sports coupe/sedan. I'm thinking that your poor fuel economy and the oil leak are very related. Get that fixed and the other should improve.

[lomita]

Thinking is cheap, especially if you never get your hands dirty doing the job.

The plugs aren't fouling because of the oil leaks from the poor design of the valve cover spark plug tube oil seals.

Just came back from the dealer for a hands on view of the valve covers. The valve covers are composite material, you know, like some junk plastic toy. The $2 rubber oil seals are sandwiched between the outer valve cover and an oil splash plate bonded to the inside of the valve cover. This is a very cheap design at best. Infiniti just lost me as a consumer. This engine part is a tinker toy.

[BigWill]

Did you think you were buying a Toyota?

Sounds to me like he's thinking of buying a gun!

(That's three.... BANG!!)

[Sentientbydesign]

But I do all of my own mechanical work!!! lol

Which year coupe do you have?

[lomita]

We have a shop manual.

We got the plugs changed.

The oil seals are scheduled to be dealt with in a couple more weeks (warranty covered, the valve covers have to be replaced).

Took about a week before the check engine light finally turned itself off just from changing the plugs! There were no codes thrown during the entire period, the CEL just remained on. Must have been the old gas cap issue.

Also tried clearing the CEL with the OBD code reader.

The manual was very vague about how long it would take for the CEL to reset itself.

The plug change was very straight forward, no rocket science involved here.

The valve covers are designed to reduce noise emissions and vibrations, hence, not metal design.

It appears the OEM plugs were a little tired at 21,000 miles! The vehicle has improved in fuel mileage, at least on the highway and we are monitoring the city fuel mileage now.

Thanks for the heads up about not posting the 05 year of the vehicle, and thanks for the interest overall.

[impulsive84]

I just changed my plugs/oil yesterday, the two plug tubes closest to the firewall are leaking, which was kind of lame to find. Anyways, short of removing the valve covers I came up with a quick fix. I matched a couple of O-rings and managed to snugly fit them between the valve cover hole and the plug tube diameter. My hopes are that the coil packs will seal nicely against the O-rings, if not.. rtv it is.

[lomita]

Let us know how the fix works. How soon will you be back in there to check it?

[impulsive84]

Probably my next oil change, likely sooner though, I want to throw a Kinetix intake mani on there sometime soon, failing that I will be scrubbing down the block with some metal cleaner (it's covered in salt).

[YangG35]

i have the same damn problem with my G, and its pissing me off, especially when i am told i have to buy the whole valve cover in order for me to replace my grommet seal leakage...for 2bill$ this is rediculus...anyone know where i can buy just the seal or know a performance shop that sell a nice valve cover set...maybe then if i buy a new valve cover set with some kind of performance name on it will make me feel better for paying 2Bill$...

[tollboothwilley]

#1) Infinity != (not equal) Infiniti - change the signature

#2) There is a sticky on this, I fixed mine.

These valve covers must be replaced as a whole. There isn't a "seal" that you can just replace. Plus, if you are going to go through the trouble to take off the intake, the upper and lower plenums and the valve covers off, you might at well just replace them.

sorry, but there isn't an easy fix like just a gasket, but you should also replace the gasket that seals the valve cover to the head.

[nuctech99m]

I don't know if anyone has told you, but I had the same problem, I was able to take it to my Infiniti dealer and they covered it under the warranty, you may want to go to your dealership and find out if it is covered under your warranty.

It saved me quite a bit of money.

[tollboothwilley]

Falls under the powertrain warranty.

6 year/ 70,000 miles