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2004 xterra oil burning due to leak from head cover gaskets

2K views 14 replies 4 participants last post by  03x 
#1 ·
The fumes were literally poisoning me. I'm not a particularly seasoned car guy, but the tutorials for the passenger side seemed relatively easy.. ive since covered the intake with duct tape to keep them from entering cabin to relatively good effect.....any particular tutorial or guides or advice for this sort of endeavor?
 
#3 ·
Yes. Passenger side is pretty easy to do. Driver side is a little tougher since there is more parts removed. There's a pretty good thread on here on how to change the driver side. I had the same leak first from passenger side, so I changed the gasket. But driver side started recently. I only tightened the bolts on the valve cover and it has stopped. Them bolts like to back themselves out over time. Just don't go too tight with them. It can make the leak worse
 
#4 · (Edited)
There should be a number of decent video tutorials on YouTube. Watch them and familiarize yourself with the procedures. If you still don't feel comfortable doing it, get a professional, but here are a few helpful tips.

Here is the link for the Factory Service Manual.


Download all of the files to a single folder. Open the idx file using Acrobat reader (not a web browser). Opening in Adobe Acrobat reader will allow you to click on the item you want to see and will automatically open the section and page you clicked. This makes life much easier.

Very few specialty tools will be needed if it's a straight removal and reinstall. If a specialty tool is needed you should check with your local Pepboys or Autozone etc. as most franchise stores will have a tool loan program. You pay a deposit (the price of the tool) and they refund it when you return the tool (Do not lose your receipt).

1) Don't re-use any of the gaskets. Buy new ones.
2) Don't use RTV on any of the gaskets. It just makes a mess and makes it way harder the next time you're in there because you will have to remove it. The gaskets are designed to go in dry.
3) DO use torque wrenches. You will need both a ft-lb and an inch-lb torque wrench. Pay close attention to whether it's supposed to be in ft-lb or inch-lb as using the wrong units may result in stripped bolt holes and/or broken parts.
4) Take your time. Research the process fully and watch the videos several times before you start taking things apart.
5) use a sharpie to number both sides of each wire connection. 1 and 1, 2 and 2 etc. This will make your life a million times easier when it comes time to button things back up.
6) Be very gently with your wire harness. It is 15 to 16 years old and has spent it's life in a very hot and harsh environment. Bending it harshly will often result in breaks in the wires and it is a major pain to find a short in the harness. (I actually went over my entire harness with a full double wrap of electrical tape to refresh the old crumbling tape. This also gives the harness case a little more support.
7) When you put things back together be sure to put a dab of dielectric grease on the pins of each connector. This will help prevent corrosion.
8) There are a few "while you're in there" items. While you are in there inspect all the coolant hoses under the manifold. Replace any that look questionable. Re-use the spring clamps if they are still there. The worm drive clamps WILL leak after a bunch of heating and cooling cycles and the only way to retighten them is to take everything apart again. The spring clamps are designed to expand and contract and always be tight. You may want to replace the knock sensor (they go bad frequently). You should take this opportunity to replace the bypass hose (It's an elbow) that goes to the thermostat housing. It's relatively inexpensive, but if it blows you'll just be taking everything apart again to get to it.

I'll add more as I think of stuff and I'm sure some of the other guys will chime in.
 
#6 ·
Yeah man. I'm not guaranteeing it. And I couldn't even get all the bolts. But I just used a rachet extension, a 1/4 socket, and taped a Philips bit in it so it wouldn't fall out. Got the ones I could get to good and tight, cleaned up the oil around the area so I could check a couple days later to see if there was still any kind of leak. No issues since and it's been a few weeks
 
#7 ·
Hey there! I did this procedure quite recently, as mine were also leaking. I am in no way a mechanic either, nor did I have much experience with it, but just taking your time and remembering the basics is really all you'll need. The only stinker are getting those coolant lines off of the back, that set me back a couple of hours. Eventually cut them and replaced them while I was in their because they were NOT coming off. Other than that, nothing was too complicated. The gaskets are very cheap, and although some of the guides may recommend the gasket for the EGR valve, I did not bother taking that part off, thus not needing that gasket. I would add to the "while you're in there" items; the fuel pressure regulator for some reason are known to go bad on these, or so it would seem. You'll eventually take a vacuum line off that connects it to the manifold, and if fuel comes out of that vacuum line, it'll need replacing. Another one I would add is spark plugs, specifically for that #6 spark plug, not too expensive either. The last item would be fuel injectors, since there are 3 of them that are hiding underneath the manifold, but generally they're okay, haven't heard too many people with problems with those and they are relatively expensive, but just bringing it up since they are also visible, but like I said, probably nothing to worry about on them, unless you're having some type of problems that may lead you to suspect they're bad.

Good luck. If you have any more questions, feel free to ask!
 
#8 · (Edited)
The FPR is a good idea, since if it does go bad you will have to take everything off again to get to it.
I've never had a problem getting to my #6 plug. I just use a variety of wobble extenders and a universal jointed extender. If you ever do the plugs with the intake on I do recommend removing the rubber grommet insid the spark plug socket when you put the new plugs in. A new plug socket will grip the plug too tight and when you go to pull your wrench off the socket will be left behind. It's a major pain to get it off of some of the plugs if that happens and you can't put the leads on until you get it out of there.

DO use NGK Platinum plugs. They cost a little more, but they are OEM and these beasties are known to take issue to other brands of plugs. Also make sure you go by YOUR year of X and not just any first gen when selecting the plulgs. Nissan changed plug models between years so there may be a difference in gap width and plug temperature from year to year.

If you're looking for reasonably priced parts, I'm a fan or Rock Auto. Their prices will be well below the Big Box stores even after shipping and they should get your parts to you within 3 to 4 days.They carry many off brand parts as well as parts from the OEM manufacturer. These include:

1) NGK for plugs
2) Hitachi for knock sensor, distributor, MAF sensor
3) Bosche for O2 sensors

Obviously this is not a full list, but the site will generally tell you if it's the actual OEM part.
It is also generally recommended to replace the little gromets go under the screw heads on your valve cover. They're rubber with a metal washer and get hard and brittle over time. This results in them not being able to provide proper or consistent pressure to the VC and VCG which may result in leaks (as does an old brittle VCG)
 
#9 ·
y'all bosses are amazing people thank you for your wealth of knowledge and sharing your experience. I haven't tackled it yet as I want to get the tortion wrench and a few other things.....would you suggest degreasing the cover insides before reinstallation?
 
#12 ·
Yes. You can usually get one as a loaner with a deposit at Autozone. If you decide you like it, keep it. At least that's the way it works here. The deposit is the purchase price and that's how I got my inch-lb torque wrench. The one they loan is OEM brand and the one they sell on the shelf is OEM branded, but the oen they loan comes with a nice case for the same price.
 
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