Dolphinride

My 2003 Maxima has right at 100k miles on it. I have owned it for maybe 4 years, and since it had 42k miles. I change the oil religiously. Castrol conventional, and Molbil1 filter. I thought I had noticed a slight misfire lately. However, today the misfire became VERY pronounced. One of the cylinders is obviously not firing at all. The check engine light came on pretty quickly and the OBD scanner recalled a P0303 code. I stopped at an Advance Discount Auto Parts and bought a new coil, and installed it in the middle front slot. That is cylinder 3, correct? That did not fix the problem, so I switched the coil packs around, putting the new one in another slot, and the one I thought was bad in yet another slot. Same symptoms. I then bought a new spark plug and put it in the middle front slot. No change.

Any insight on where to look next, please? How do I figure out what is wrong and fix it?

Could it be the fuel injector? Would the car exhibit these symptoms if that was the problem?

Praying it is not my rings or motor...

nestorlugo

iTrader: (11)

Yes look on the right side of the engine which is middle rear(firewall side) uim must come off....spark plug proly swimming in oil,you gonna need a few gaskets too!

acw

I would not panic....its probably a sensor issue or wires/electrical. Someone here will come along with better answers. Did you change all the plugs ? I would at least change the front 3....that's easy enough.

Unclejunebug

Coil #3 is in the middle rear slot by the firewall. Sounds like you changed the wrong coil. UIM needs to be removed to do the swap. As nestorlugo mentioned you most likely have oil in the plug tube due to a bad valve cover. Common problem.

Dolphinride

My mechanic looked at my maxima. He confirmed that the rear cylinder bank seems to be the problem. The spark plug tube on cylinder #5 was filled with oil. So, here is what he suggests;

1. New valve covers as they are made of plastic and gaskets alone may not work.
I am weighing replacing only the rear valve cover, since the problem seems to be the rear, and I can always do the front later.

2. New o-rings for the rear plugs.

3. New spark plugs in back, since he is back there.

4. (3) new coils in back, since #3 is the likely culprit which is causing my misfire on cylinder 3 & my P0303 error code. Also #5 is soaked in oil.

They are telling me that the labor will be 4 hours @ $75 per hour.

I have been comparing coil prices. It looks like a generic coil on Ebay is $12.49. An OEM coil on Ebay is $75. Hitachi coils are around $50. Someone told me that the only difference between Hitachi coils and OEM Nissan coils is the packaging. Can anyone speak to this, or make a definitive recommendation as to the best coil for the money?

Any other suggestions regarding a course of action on the above?

george__

iTrader: (1)

^
Buy the gen 6 valve covers (2005+)

ignition coils - only get OEM or Hitachi (RockAuto)

slag

When it comes to spark plugs, do we stick with NGK or is there a better alternative? What's the best place to get a good price on plugs? I was checking out NGK the other day at advance auto and they were about $6.00 per plug which I thought were kind of high.

Heel Til I Die

Only replace coils with OEM and the most recent model. Ask me how I know...

Plenty of threads on here about upgrading to the newer valve cover also. Seems to be the majority opinion.

I have always stayed with NGK iridium plugs and have had zero problems. I think their price is reasonable (and justified).

Dolphinride

Yes, sir. I will. Here goes 'how do you know'?

Dolphinride

Would someone please be kind enough to provide a part number for the updated valve cover?

Are both the front & back updated, or just the back?

Dolphinride

And just to be clear, please. Your opinion... NOT Hitachi... OEM Straight Nissan branded dealership coils only. Correct?

george__

iTrader: (1)

You're going to get a huge bill buying ignition coils from the dealership

Unclejunebug

I'll do you one better, here's a link. Unfortunately Nissan doubled the price of these somewhat recently, but they're still cheaper than the 5th gen covers that are flawed.

EDIT: Strange, the first link I pasted went to the 2002 version for some reason. Fixed.

EDIT2: ARGH! It keeps going to the 2002 cover for some reason. Just search that site and you'll find it.

Dolphinride

I am thinking I am going to call Poway Nissan tomorrow, or just go to my local stealership to ask them which valve cover part #'s will fit on my maxima, and which ones are the best to use.

I will also check on the gaskets and O-rings.

I am thinking I am going to go with the Hitachi coils. I guess I dont really feel safe going with the $13 generics, and I dont want to spend $75 per for the Nissan branded ones.

LWilspeed

I bought a number of different coils for my last Maxima and even though it cured the misfire (and codes for misfire) it cause other check engine lights related to funny resistance readings. Only OEM coils cured it - in hind sight I would have been better off buying OEM the first go around. I would recommend going with the OEM coils...If you are strapped for money maybe you can find an updated used set online somewhere or at a junkyard.

Heel Til I Die

LOL. Here's some light reading for you...

Similar to a lot of people on here, sometimes I tried to cheap out and get the generic/off-brand coils. They would either prematurely fail or I would have to replace the same coil again since it would throw a code or the SES light would come on.

First it was the original coils from the factory that failed back in 2003, I think. The ones with no dot on them. Mechanics and shops were stumped. Maybe the gas cap isn't on tight enough, they told me... durp.

Before, it was a commonly known problem, I replaced them with new coils (more with no dots). When those failed and the problem became more prevalent, the magical coils with the grey dot came out. One by one, I ended up replacing the original coils with the grey dot models.

Then I started having the same issues again. Tried to get cheapo ones which would crap out quickly. Then came the newer models with a pink dot. I now have all ignition coils with the newest pink dot version (at least newest in 2013) and have had zero problems since then.

I guess the moral of the story is: don't get off-brand unless you're just looking for a temporary fix and want to become skilled at changing coils

IIRC, last time I changed the coils, I think the OEM from the dealership were Hitachi brand. Just make sure you get the newest version!

Also, try courtesyparts. Their price may be better than your local stealership.

Good luck!

george__

iTrader: (1)

hitachi IS/WAS OEM supplier for Nissan I think?

Unclejunebug

Chances are the dealership will not tell you that you can use a 6th gen valve cover as a replacement. Reason being...

1. The 5th gen valve covers are quite a bit more expensive than the 6th gens
2. The may not know the 6th gen covers can be used as a direct fit replacement

Also, in your post above (#5) you mention your mechanic suggested "New o-rings for the rear plugs." The only seal for the spark plug tubes is built into the valve cover itself. If you replace the valve cover you replace the tube seals. There's no extra O-ring whatsoever so don't be suckered by that if he's trying to pull one over on you.

NmexMAX

iTrader: (22)

The best VC’s for your car are the 04-08 VC’s. Reason being, the coil tubes are updated and do not fail as the 02/3 tubes have. Recently they have more than doubled the price. They were around 30$ or so, now they’re 90+ I believe. Still, a viable option given the updated design.
I’ve always gone with OEM coils, but recently I went with an off/non Nissan distributor (still Hitatchi) and only paid 52$ and it’s been fine.

Also, it’s the # 5 cyl that most often fails due to the coil tube getting beat up and cracking, not the #3. So, if and when you get the chance to remove that UIM(upper intake manifold), check the #5 cyl. Mine was full of oil @ 155k. I changed the plugs @ 100k, and all looked fine. For future reference, remember the odd numbered cylinders are near the firewall, and the even numbered are up front. One thing about the 02-08 coils is that they are all the same configuration, vs the 95-01, where the rears are a little longer due to them being able to be removed without removing the UIM.


Here’s a good background link regarding the valve covers: https://maxima.org/forums/5th-genera...overs-pic.html

About the spark plugs, I go with the Iridium IX, cheaper than OEM Pt, about 8$ per plug. On my second set now.

Dolphinride

I am looking at the different plugs on RockAuto. Are these the ones that you are advising that I get?;

NGK Part # 5018 {#LFR5AGP} G-Power $5.71 each

Heel Til I Die

I think I used these guys:

NGK Part # 5464 {#7964, BKR5EIX11} Iridium IX .044 $6.27