My 2004 disco with 70K mi has been leaking oil from the valve covers. Did a little searching and decided to just tighten the outside bolts. Everything was going fine, torqued the first three to 10 ft/lbs and the fourth (passenger side back) broke in half. My torque wrench never clicked. I think I need a new one.

Now I need to extract the bottom 1/2 of the bolt and put a new one in it.
1) Does anyone know the best tool / drill bit size and type to do this?
2) Is that a short or long bolt? It's the passenger side, outside, closest to the firewall.
3) Any tips from someone else that has done this job before?

TIA, - Ryan (who is not used to working on Land Rovers yet, long time BMW tinkerer )

 

Well the 1st three outside bolt you removed are the same size as the 4th that is broken. Take one of the the three to your local hardware store and i'm sure they will be able to give you the best tool to remove it.

This is the only thing i can think of doing unless anyone on here verifies the diameter and length for you then gives you the correct drill size/bit to use.

But be careful about the advice you get from these guys!....lol j/k

 

If you remove your valve cover, i'll bet it will come out with your fingers.

 

But on a 2004 it will be quicker and cheaper to extract it out. IMO... Otherwise you have to remove the upper intake manifold and a couple other things..... i just did that two weeks ago while replacing my valve cover gaskets and valley pan gasket and i wouldn't go through all that trouble "IF" i can extract the broken bolt a different way...

 

Funny thing is now with the three tightened and the 4th broken, it is leaking less maybe not at all. General question about LR gaskets - these things seem to be very think and made of rubber. Why is that? Does it make the tolerances higher for keeping a good seal? from what I can tell by what is visible w/o removing the cover, these are the thickest gaskets I have ever seen, I'm used to working with paper-thin ones. Is it even a big deal that one bolt is missing?

 

Yes, a missing bolt is a big deal. I am assuming you were retorquing the bolts like everyone here suggests because your valve covers were leaking. If they leaked with all the bolts there, why would the same gaskets not leak with a bolt missing?

 

Because they were all very loose. Not even finger tight. So now all but one of the 4 "easy access" ones are tight. So one side is good and the other is 1/2 better (in my mind). Good to know it is a big deal, I won't put it off. Once I get the trouble bolt r&r I can degrease it and check for leaks.

 

The problem lies in the fact that the bolts loosen up over time. And with 3 bolts doing the job of 4 that process will be accelerated.

 

The stock valve cover bolts are aluminum. Depending upon where it broke will determine how easy or hard this will be. I feel your pain I got a broken valve cover bolt one out of my D1 as follows:

1 - Remove valve cover and valve cover gasket.

2 - If the break was near the head or above the bottom of the valve cover gasket, removal of the valve cover gasket may provide you with enough of a stub to use a vice-grip and slowly back the shaft of the bolt out.

3 - If the break is below the valve cover gasket and into the block (like mine was)...

3a - Obtain a small hardened cement flooring nail. These are flat steel nails with a triangular shape. The point of the nail and the nail shaft need to be smaller than the diameter of the valve cover bolt. Home Depot has them.

3b - Drill a small hole or dimple dead center into the broken valve cover bolt. Perhaps just 1/16 of an inch. Place shop towels around the drill area to catch any shavings that fly away… no sense adding metal shavings into the engine.

3c - Tap the hardened nail into the broken valve cover bolt. Hit it hard enough so that the steel nail gets well enough into the broken bolt so that the nail shaft can be used to turn and back the broken bolt out. Back it out enough to get a vice grip on the stub for the rest of the trip out. The broken bolt is aluminum and the steel nail should drive nicely into the bolt shaft. If you hit it too hard the nail will bend. Slowly with more taps is better than fast with too much force.

4 - Other option would be to drill the broken bolt out, but then you may will have to use a tap & die kit to re-thread the receiver a little wider to accept another sized bolt, which also may require you to widen the hole on the valve cover gasket.
I have seen special bits that can be hammered into a broken bolt and then used to turn the bolt out… but nothing for a small diameter bolt.

While at Home Depot... purchase Stainless Steel replacement bolts. I believe they are 3/16 for a D1. Two different lengths... just match up what you have. The stainless will tighten better, and won’t break. Do not worry about stainless to aluminum mis-matched metal corrosion... there is no air in there, and if it does corrode you will long have left this world when and if it makes any difference.

One last thing… the Rave manual specs all to torques in nm … NOT Foot Pounds. To convert the nm spec to foot pounds divide the nm number by 1.365. So 10nm equals 7.32 foot pounds. I doubt the extra 3 lbs broke the bolt… unless you maybe were using a deep socket or extension? Torque wrenches assume you use a low height or normal socket. Deeper sockets and socket extensions (aka breaker bars) of any length add torque at the bolt head, but measure less torque at the torque wrench. If you are **** about this… most torque wrenches will provide you with some simple mathematical formulas for torque settings if you must employ either deep sockets or socket extensions (aka breaker bars). Aluminum bolts have a very low tolerance for over tightening.

Anyway... it worked for me.

Joe

 

You can try an extractor tool. I have used them before with success. I too have worked on many BMW's. My wife drives #5, a 95 525I with 169k on the clock. Click on the link for the tool options.

http://www.sears.com/shc/s/search_10...bolts&sLevel=0