Crown Nut Snapped

So here I am cleaning my engine yesterday (D15B2) and I come to the valve cover. Test the crown nuts to make sure they are on nice and tight and the right hand front one is loose to the point I have play with it in my hand. So I give it a quick spin with the wrench and it snaps off, taking the top of the bolt. Now here is the question(s):

1) Is the engine in any mortal danger? The bolt still seems to be jammed in place so the valve cover hasn't moved.

2) How would I go about replacing the bolt? Is it simple or am I going to be digging around there like a strip mine?

3) Can I replace the bolt by myself or if I take it to a shop how long should it take to fix?

you might have to take it to a machine shop and have them drill out the old bolt, re-tap the hole and install a new one. it could begin to start a problem of not sealing correctly and you can have oil leaking all over the place.

Remove the valve cover & replace the broken stud & crown nut. Should only be a couple bucks from the dealer. The fix is pretty simple. Since it is a closed nut, it can only be tighten so much. If the valve cover gasket is old, it may be wise to replace that also.

like jackasssi said, just change the stud. hopefully the stud didnt break in the head, but rather the stud broke on your crown nut.

Ok, the good news is that it broke right up at the top, and it is flush with the valve cover. Does that make a difference in the issue? And the valve gasket is new, just put in about 3 weeks ago.

If it's flush with the cover you should be good to do it yourself. Pull the cover and get a visegrip on the broken stud then turn it out. Just make sure you use care and dont scar up the head with the visegrips.

As people are saying, it's not as bad as it looks. When you pull the valve cover off, you'll realize that the stud is actually fairly long, and there should be plenty of room to grab the stud and unscrew it from the head

it's not nearly as painful as if you broke a bolt off in the head or something like that. just be glad it broke at the top end and not the bottom!

If it's flush with the cover you should be good to do it yourself. Pull the cover and get a visegrip on the broken stud then turn it out. Just make sure you use care and dont scar up the head with the visegrips
Dont Use Vice Grips :grinno:

Simply remove the remaing valve cover nuts
Remove the v/cover
Use a 10mm wrench or 10mm deep socket for removing the stud. An impact would be the safest for removing the stud.
DO NOT over tighten the new stud or crown nuts.

If you can't get a new stud, I have some at the shop & will sell for cost of shipping. Just let me know the length since there are various sizes - usually 2 long & 2 short on Honda's.

O/T Nissan v/covers are held on the same except with 10 or more crown nuts. I had a car recently in shop with 6 of the 11 broken :disappoin.

Damn, if that was my car.... I get nervous for one.....but 6? I would be crying all around town. Ok, I am guessing since you want me to use a 10mm socket to extract it that this is just a standard bolt in, bolt out procedure, am I correct?

Yes it's a standard bolt-in procedure. The stud is basically a 2 ended bolt with a nut in the middle, 1 part goes in the head & other part goes through the v/cover for the crown nut. Once the v/cover is removed it should be pretty easy to figure out. Now if your having trouble removing the old stud, STOP & take it some where with an impact gun to reduce the chance of it breaking in the head.

Sorry, didnt know they had a head in the middle you could get on :uhoh: Learn more everyday :icon16: Most I have had to deal with are just blank in the middle.

I've searched the manaul a few times & can not find any info on the studs, no torque spec/picture. I could always take a pic of one @ the shop if your that curious.

This is the best illustration I can find in the manual -- you can see the threaded rod at the top then a thicker post with a nut below that/mating to the cylinder head surface. Below the nut is another threaded rod, just like the top part.
http://www.imagestation.com/picture/sraid95/p75f4fff5fbccb1c859669f29075bfa70/fa29b270.jpg

Thanks jackasssi, all the info is gonna help. The earliest I can tackle this is on tueday -- im stuck at work tomorrow. Who would have thought people would be in a water park three days after christmas. So in conclusion, just go off to the dealership and pick up a new stud and etc? Sorry if I sound like a lost case, but busted studs (wheel and etc) arent covered in the standard manuals.

I'm pretty sure the tq. specs are for 7ft lbs.

I'm pretty sure the tq. specs are for 7ft lbs.

Thats the first thing I checked after the nut went kaput. :banghead: Now I will read all that information before tightening random odds and ends.

Good thinking. Always check tq. specs first.