broken bolt...

[Joopin]

1071794

a couple weeks ago I changed my valve cover gasket and cleaned the whole top of the engine. I noticed today when I was changing the oil that the rear of the valve cover seemed to be leaking and going down the side of the block. I tested one of the bolts to see how tight it was and it didn't seem tight at all! So i tightend it and went onto the next one, then the next one... and then one broke! It didn't even seem tight! Anyway, I hope to drill out the bolt and tap the hole WITH the cover still on...
So do you think it will cause a problem if I drive around with a bolt broken? Does anyone have an idea why it's leaking in the back of the valve cover? I know that the bolts have to be equally tight, with a torque wrench, but I dont' have one... I guess I should buy one so crap like this doesn't happen.... This just makes me want to rebuild the engine! 195k and counting...[addsig]

 

[Utah_jeepster]

1071795

You have multible questions here....I can only answer a couple of them.
First as an Industrial machinist who does alot of R&R of broken bolts on large fan, and water pumps for the mining industry. I would first recomend that you DO NOT attempt to drill out thje bolt while the cover is on. If one stray metal sliver gets into the wrong spot it could damage a cylinder wall, a valve guild or excetra...
The best and safest way is to remove the cover and attempt to drill smaller for an EZ-Out. I do not like using these ex-outs while the broken bolt is still protruding from the valve head. Since the the EZ-OUT is swedged into the drilled out hole it flares the bolt allowing you to remove it. If it protruding from the valve body the ez-out flares the broken screw and while trying to turn it out it can flare a bit more and slip...all ez-outs are made from tool steel and tempered to 50 rockwell and above and being that hard they can snap. I would recomend that you pull the cover and cover the valves with cloth to catch all metal chips. cut or grind the bolt off to flush...use a sharp punch center punch a drill starting location, and use a smaller drill then recomended and work up so if your slightly off angle you dont drill into the exsisting threads. (cobolt drills work best on SEA harden type of bolts than high speed steel drills)
I prefer the ez-outs with a shoulder than to the 4 fluted tapered design.(less breakage)
Once out chase the threads with a tap and use a removable lock-tight type of thread locker for high heat type of aplications will keep them from untightening in a slightly worn thread.
Note you might want to also check with your local parts supplyer if there is a toque pattern you have to follow.

Good luck with your broken bolt[addsig]

 

[jps4jeep]

1071899

Did you use any ultra-blue or any other gasket sealer when re-install (not that it effects the broken bolt) also I have found that a little thread lock on valve covers go a long way! Replaced the gaskets three seperate times (different sides each time) cause the bolt were shaking loose (not that the lopey cam was helping hehe) on my 77 blazer.
Little threadlock (I used the liquid type) did the trick.[addsig]

 

[84_CJ7]

1071903

If you take the cover off there is a CHANCE that enough of the bolt is still protruding enough for you to grab it with some vice grips and back it out. If not, Utah Jeepster is right on target. I would recommend removing the valve cover no matter what you do. As far as driving around with a broken bolt, it wil just leak MORE. And about the locktite, make sure you use the BLUE and NOT the RED. Red is permanent.
When you repair and replace your cover you may want to silicone the gasket to the cover before you replace it. It will help seal and keep it in position while you replace the cover. Good luck.

Scott[addsig]

 

[Joopin]

1071925

No I didn't use the thread lock! That probably would have helped... I did use the gasket sealer though to stick it to the cover. I don't know if any of the bolt is sticking out of the head or not, I was too pissed off to look after I broke it. Don't you think shavings would get into the head if I take the cover off to use the EZ out? It looks like you guys are telling me to take it off! Anyway, I will go buy an EZ out, BLUE thread lock, and a new gasket... Someone told me to use a torque wrench when tightening valve cover bolts to get them all the same... I never heard of that in all my years of working on cars etc... well thanks for the help![addsig]

 

[84_CJ7]

1071928

Just make sure you lay something over the valve area to keep any debris out. And be careful when you remove it so the stuff you have collected doesn't get away from you and fall in what you were protecting. I don't remember what the torque for the valve cover bolts are but I assure you there is a recommended amount. Too loose and it leaks and too tight and it leaks. Way too many mechanical rules in this world!

Scott[addsig]

 

[Tug-n-pull]

1071943

Set a good strong magnet near the drilling poit to help catch most of the shaveings. EZ out is the best choice by all means. tug[addsig]

 

[84_CJ7]

1071944

Forgot about the magnet! They're great to have around for all sorts of things. Like that bolt you're sure you dropped right there . . . .

Scott[addsig]

 

[Bounty__Hunter]

1071945

Make sure your PCV system is working correctly. If it's clogged, you'll build pressure in the valve cover and blow the gasket.[addsig]

 

[Snitty]

1071965

yeah... anything being bolted into the head or block should be tightened to specified torque... for that matter... anything bolted anywhere should be tightened with a torque wrench[addsig]

 

[Utah_jeepster]

1071971

yeah... anything being bolted into the head or block should be tightened to specified torque... for that matter... anything bolted anywhere should be tightened with a torque wrench

I talked to a fellow jeepster at the shop today and he told me that if he remembers right the valve cover is torqued to 20 inch pounds...please note thats inch pounds not foot pounds. but when you buy your new gasket any parts supply shop can provide you that information and if there is a torque seqence.[addsig]