At 104,000 miles I finally decided to change my sparkplugs. I was tempted to have my local mechanic do it for $100 labor, but ended up doing it today in my driveway. The threads here really helped with the process, it was fairly straightforward as long as you have a 10mm, 12mm and 14mm sockets and a sparkplug socket. A torque wrench it nice too, but I swear the plugs could have been removed without a ratchet, they were in pretty loose.

Anyway, I don't think the original owner did any maintenance except replace the struts once and the clutch at 30,000 miles.

Is it possible these plugs have 104,000 miles on them? If they do, they look like they could go another 100,000 miles. Every one of them had perfect color, no oil, no burned tips, very little ash.

BTW, when I put the IM back on, I did not put the two rear bolts back on it, the ones next to the firewall. Are those a real necessity, or do most of you guys leave them off?

I also re-used the original IM gasket. Nothing seemed wrong with it, and since it was already self-positioned...

Also, there was just a bit of wet oil on the rear, driver-side coil body. Nothing in the spark plug well itself, so I guess I have escaped having to replace the rear valve cover with an '04.

 

I did mine when I bought this @ 95k and they looked to be in comparable shape. Don't know that they had been done on mine. Nonetheless i replaced them as part of a tuneup so I know where I was starting in terms of maintenance.

What happened with the clutch? That is really low mileage for replacement.

 

It was replaced again at 85,000 miles when I bought the car.
Original driver lived in a stop-and-go town that always has very heavy traffic.

 

Those are probably the original plugs.

With the intake manifold, you did 2 bad things.
1 - you did not use a new gasket. Maybe it is OK for right now, but it will be drying up and will lose its sealing ability.

2 - You did not put all the bolts back in. By not doing this and not being able to torque the bolts properly, you have greatly increased the probability that the upper intake manifold (the part you took off) will warp and pull away from the lower intake maniford. When coupled with an older drying out gasket, you will develop a vacuum leak and the car won't run very well. When the upper intake manifold warps, you'll be buying a new one.

But it's your car.

 

I changed mine and I swear they were the originals, (mind you I changed them out at 196,000km) one should never reuse an old gasket (rule #1) as for not replacing all the bolts that is like only putting back only three lug nuts to hold the wheel on, always put back everything nut and bolt (rule #2) escaping having to change the rear value cover to the upgraded 04 version ... well, now you will have to remove everything once again to do that job, so ... do everything right the first time so you don't have to redo things shortly after (rule #3)

It was a good thing that you attempted to do the work yourself, always a good learning experience with just a little bit more planning and making sure you have everything you need to do a complete job and doing it right the first time you will learn that it pays for itself extremely well and peace of mind.

 

A little bit harsh but well and enough said !

 

This is how the original plugs on my 06 Jetta 2.5 looked and it only has 57k










Not to thread jack but if anyone knows what appears to be on them or why pm me...

 

Probably what that german version of that gel you are supposed to put on the plugs looks like after it's been cooked

 

LOL, you guys are tough. Let me clarify a couple of thing. The two bolts I did not put back on are the two at the very back of the engine next to the firewall. They are in no way related to the 5 bolts that hold the UpperIM to the Lower IM, and should not affedt warpage or placement of the manafold.

In several years of being on Maxima and Altima forums, I have encountered numerous posts where people (especially those who removed their IM on a regular basis) left those bolts off. In fact, I believe that if you do the phenolic spacers mod, you MUST leave those bolts off, so I bet everyone here who has spacers has not replaced those bolts either.

Many of those people also did not replace the Upper intake manifold gasket. I think it is a metal gasket, so whoever said something about it drying out may not have done this before. If it leaks, I can replace it fairly easily.

If the two rear bolts are really a big deal, I can pop them back on; nothing has to be removed to put them back in place as they sit back there by themselves.

I just took the car for a 40 mile trip and it runs great, and no codes. The entire operation went exactly as I wanted it to. I don't like to throw money at 10 year old cars unless they really need it for reliable operation.

Reason I did not replace the rear valve cover is because it did not need replacing. There was no puddle in the spark plug well, just a light glaze on part of the side of the coil pack. If it looks the same at 200,000 miles, I won't replace it then either.

Now I admit, the Nissan FSM recommends replacing the UIM gasket whenever it is removed.
Screw Nissan. That money would be better spent replacing the alternator or starter when they don't need it instead, as they have a much higher probability of failure.


A note of interest; My car still burns about 1/2 qt per 1000 miles. But looking at the plugs, that oil is not going into the combustion chamber (i.e. it's not getting past the rings) or the plugs would look sooty.

It's not leaking on the ground, its not leaking into the spark plug wells, it's not leaking from valve covers.
Where the hell is that 1/2 qt going?

 

from the Intake Manifold. oil g ets in there from the vacuum and gets burned off. did you clean out the inside of the manifold? if you didnt, take off the VIAS thingy and look inside.

 

Really? Do you understand lever arms? And moments caused by suspended masses?
It isn't just about how it works right after after you put it together.
^^This, for example...
Yeah, stick it to the man!
Couldn't have said it better. In short, I agree with the points that others brought up, and would not do this on my car.
btw, the previous owner of my car needed the clutch replaced at 30k miles, too.

 

I would think that after ten years of operation, it's as "dry" as it going to get.

 

wrong on both parts

 

Nice plugs mine look like 2 times as bad but guess it depends on the driving also...

 

I changed my original at 115k

 

So I guess all those folks who run NWP spacers are going to have the IM warp on them?

 

I have done about 10 spark plug changes and phenolic spacer installs on various 02+ Maximas. About 75% of the time the gasket between the upper and lower plenum is still ok. 25% of the time it is shot.
When you take a look at the gasket, it is pretty obvious if it needs to be replaced or not. If it comes off clean you should be ok. If the black "plastic" part is stuck to the mating surfaces, and flaking all over the place, you should get a new one.
As for the extra support on the back of the upper IM, it probably serves a purpose, I'm sure the nissan engineers thought it was a good idea, but there are hundreds of people out there not using it and they have not had any problems. IE phenolic spacer installs

 

Yes knight, that is exactly how mine came off; one piece, nothing stuck to the mating surfaces, it looks like it is new.

I was pretty aware that everyone with spacers has those back two bolts removed, and I've never heard of any issues that it caused. These guys think I'm a noob or something I guess. Been around cars all my life, it is my business as well. I just don't spend unnecessary money these days if I can avoid it with no ill consequences, on all three of the Maximas that I own. For you guys who have the time and money to spend on things that ain't broke, hey, its your life, do what you like.