2000 Pathfinder, 3.3 valve cover gaskets

[JoBlack]

Hi, I am new to the forum and have decided to tackle the valve cover gaskets on my Pathfinder. I stopped driving it when it started leaking oil last year and have decided to tackle it while I have a little time off work. While I am doing the job I will also change the spark plugs. I started today and want to share some tips and ask for help along the way.

Day 1. Today I began taking things apart, my engine is fairly corroded so removing some simple bolts and clamps can turn challenging. One tip to share- I drop a small amount of penetrating oil on the end of a flat screwdriver and touch it to a bolt. The oil wicks around the bolt and frees things up without having to spray a mess of oil all over. I attached some flexible tubing to my air gun. I started with blowing as much dirt and debris off of the engine and soaking bolts with penetrating oil. I had difficulties pulling apart electrical connectors prior to googling it. If it is your first time, watch a video, they are tricky. You need to slide the green tabs with the arrow into the connector before pulling the connector off. Mine haven’t been apart in years, I had to rock the green slider back and forth repeatedly until it would lock in. I also had to fight with the connectors stuck on the metal mount tabs on the valve covers rocking them as well. I was able to disconnect and free up the passenger side valve cover electrical connectors and harness. The valve cover popped off easily showing me the split on the lower edge of the gasket causing the oil to leak onto the exhaust. I have some carbon deposits to clean tomorrow and I will re install the cover with a new gasket.

I soaked the upper intake plenum bolts for a few hours before removal. I used a metal pick to clean out the 5 Allen head bolts and seated my Allen socket with a hammer prior to loosening. The third bolt stripped. I changed from a 6mm to 1/4” and hammered it home, still stripped. I drilled out the Allen bolt head, will have to remove the rest of the bolt after the intake is off. The three screws for the throttle bracket above the EGR pipe were a bugger, very tight. I came close to stripping the screw head on one but got them out using a ratchet and no3 Phillips tip. I will buy a 30mm wrench for the EGR pipe tomorrow. I took off so many hoses and connectors.

Some questions.... Do you put any products on the new gaskets to help them seal? I bought a Felpro rubber set, the existing gasket doesn’t show any signs of silicone or adhesives.
Is loosening the 30mm EGR pipe fitting the way to go or is it better to remove the other EGR mount bolts? Everything looks rusty
I have read that some people lift the upper intake plenum without draining the coolant or disconnecting everything from the back of the plenum. Is that preferable to draining the coolant and removing the plenum free of the motor? If I can sneak out the drivers side valve cover maybe I can weld a nut to the stripped Allen bolt and wind it out...
Final question, the upper plenum to lower intake gasket.... I saw someone calling it a factory shim.... I purchased a new Felpro gasket and am planning on just using that. Is there an actual shim or is it a case of mistaken identity of a metal gasket breaking down over time. I know that I may have to remove the upper plenum to clean the gasket mating surfaces

Sorry for the long post, thank you for any tips,
Jody B
Canada, Eh?

[Slumpert]

You shouldn’t need anything else on the new gasket when installing. Like yours, mine were so brittle they were cracked and hardened. Hopefully your gasket also came with replacement screw gaskets. Those were annoying to remove as well.

The EGR valve itself unbolts very easy, but it uses a blind nut bracket on the intake that is very fiddly to try to reinsert. Loosening either the top or the bottom egr tube nut is the best solution.

First time I was taking the top manifold off I shredded my hands trying to work those back coolant tube off. Next time I simply bought replacement hoses prior and used a box cutter on the hoses for quick and easy removal.

I watched a mechanic use some bungee cords to hold the intake up without disconnecting the coolant lines, but if they are old and brittle, that bending strain could easily create a failure point.

[JoBlack]

Thank you for your advice.
Day 2....lots of rain, bought a big wrench, minimal time spent working, so......Day 3
I put the gaskets in dry as you suggested. I like how they clip securely into the cover, helps out. My kit included the screw grommets. I used a torque wrench to evenly torque them down. That takes quite a while as the gaskets and grommets compress. The grommet shape changed considerably and I torqued them down at least 3 times.
I Used my new 30mm wrench for the rusty EGR tube, it came apart easily after a good soaking of penetrating oil. I think that a 1 and 3/16” wrench would also work.
The upper plenum Allen bolt(socket head cap screw) that stripped and had to be drilled out spun out by hand this morning, the threads looked good and I was going to double nut it out. It seems to have been locked together by corrosion but below the surface the bolt was clean and spun out freely
I wasn’t able to disconnect the coolant hoses.....I could move the clamps free but couldn’t move the hoses... I decided to raise the upper plenum up and hold it in place with coat hanger wire, bungees, and channel locks. I removed some screws below the plenum that secure the coolant piping. With the plenum raised you finally get reasonable access to the 2 electrical connectors that you may have been cursing if you were trying to remove them from the top, they are located at the back underside of the plenum.
Judging by the bends, I am guessing that the coolant hoses are preformed specific hoses. Mine appear to be in good shape. I like the idea of cutting and replacing them. I left mine alone as it would be a very long drive or too many lost days to order them.
The passenger side valve cover was “off like a prom dress”. The drivers side was stuck like glue and required a 90 degree pry bar and a lot of effort to remove. There is also a wiring clip attached to the back end of the cover.
It was a PITA to scrape and clean the plenum/intake surfaces with the plenum connected by coolant hoses and raised up but they came clean. I used a vacuum while doing some of the scraping to keep the dirt out.
I changed 5 of the plugs today. The old ones no longer had a visible electrode but the truck still ran fine. Needless to say they had very wide gaps . With the upper plenum in place I decided to carry on with the job.... I will try number 6 on its own after seeing if the rest of the job goes well. I used the tube on my air gun to blow out a lot of sand and dirt from around the plugs, I would recommend blowing the area out, start loosening the plug, blow them out again, then remove the plug. Lots of sand down there
Most of it is back together now.....
For tomorrow, I want to replace a piece of breather hose off of the passenger valve cover, it needs it sooner than later
Have to put on my new ignition wire set
Have to figure out how to free up the electrical connector by the throttle. There are 2 connectors stacked on the left side of the throttle, the green slider wont spring back out on the lower connector
This is a nasty job. It will be 2 long days of work or slightly more for me first time through. Would be much nicer on an engine with less corrosion. My Pathfinder has approx 345,000 kms on it. I would like to get a couple more years of dump runs and trailer loads of landscaping supplies out of it.
Now I understand why some people say to just add oil rather than fix the leak.

[JoBlack]

Day 4
All done. Spark plug #6 was a pain but not as bad as I was expecting. I couldn’t get it with a long wobble extension and socket as I have seen in some Xterra videos but I got it out with the plug socket, universal, small extension, universal, small extension. Grabbed on the first time I dropped it in and made installation easy.
Fixing the tps connector took more time than plug #6. I sprayed it with wd40 and blew it out with air repeatedly while working the release pins inside the connector. Depressing the two pins simultaneously releases the connector clip. They took a lot of time to free up, amazing how much dirt they can hold.
Time to get it reinsured I miss driving my old Pathy, today it might get its first wash in 2 years