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Valve cover oil seal leak - 1996 Nissan Maxima

All: You may remember my thread about a month ago regarding oil in spark plug chamber for cyl #5. Well I tackled the job at the time, and found a cracked oil seal (as expected) under the rear valve cover. In fact, the oil seal had worked its way out of the valve cover and had slid down along the spark plug tube.

Well... I waited a month and this evening pulled each of the rear plugs to check if my handy-work had held up and.... bad news... the seal for cylinder 5 (the same seal that had previously failed) has slid out of the valve cover groove again. When I did the job I used genuine Nissan parts and seated each of the three seals in the valve cover in an identical fashion. The other two seals I replaced look fine (as viewed from above the engine bay through the spark plug chamber with the coilpack removed).

I would be happy to admit installation error - but frankly, I'm not sure what I did wrong, since two of the seals are holding up fine and the same seal has failed again (within 1500 miles).

Any and all advice/suggestions are appreciated.

Nisstech - any thoughts on what I might have done wrong?

Thanks in advance.

Nirav

96 Max GLE, 118k
Reply to
njmodi
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Nirav, I have given this some thought and I can for the life of me come up with a good explanation/diagnosis.

but I have a few possibilities.

1, defective tube seal
  1. dare I say it, improper installation ...(sorry had to say it)
  2. if I remember correctly the seals are different from the front bank versus the rear bank , maybe you got one mixed up?
  3. the spark plug tube may be deformed in some way not permitting a good seal.

Reply to
NissTech

NissTech,

Thank you for getting back to me on this. Sorry this reply is so long.

As mentioned in my post, I would love to be at fault :) because it would mean I could do the job again, correctly this time around, and know its going to hold up. I don't know what I could have done wrong - I took pictures of the valve cover as soon as I pulled it off the car and I made sure that when I replaced the seals, they were seated to the same depth and orientation. I was careful not to damage the seal while seating them and used light taps with a rubber mallet and a large socket to get the seals flush (once I had pressed them in as far as I could by hand). Once seated, I tugged on each seal and they were tight. I even compared the old seals and new and they were exactly the same dimensions.

I tend to think that that particular seal groove (for cyl #5) has become deformed - because when I opened up the valve cover for the first time to fix the problem (last month), the cracked seal had worked its way out and was sitting on the head - the only crack was in the rubber inside that grabs the spark plug tube - so I wouldn't have expected the entire seal to dislodge from the valve cover. I didn't think about this until the problem recurred.

My path forward is as follows: I have located a 99 VQ30DE engine with

16k miles on it. I am having the valve cover (with oil seals intact) shipped to me. I will swap that VC onto my car (with a new main VC gasket). I intend to leave the factory installed tube seals in place (assuming there are no cracks, damage, as I have been promised). I know I should probably replace them, but figured that my original seals lasted me ~100k, so I should get a few years out of these ones (plus this eliminates any user error that I might be introducing). I'll pull the coils and take a peek on a few weeks - if the problem has recurred (where the seal worked its way out out of the valve cover), then it might be time for a road trip to the Southeast :)

Let me know your thoughts on my plan - I would appreciate the feedback.

Cheers, Nirav

96 Max GLE, 119k

NissTech wrote:

Reply to
njmodi

sounds like a plan to me Nirav.

Reply to
NissTech

The part is on the way - should have it today. This weekend I'm tackling LCAs and tie-rod ends. Ride is getting sloppy and it is probably not a bad time (119k, 10 yrs old) to get new LCA bushings/ball-joints on the car. I'm going to replace the swaybar bushings and the end-links too.

The valve cover job is on my schedule for next weekend!

Cheers, Nirav

96 Max GLE, 119k
Reply to
njmodi

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