Broken bolt in a BAD place!

[Inf]

Well, I just learned a very important lesson, and I guess it will prove to be a very costly one too.

I was installing my new water pump, and decided that the original bolts looked ok. Wrong! I guess years of heating up and cooling down created some small cracks in one of them.

Just now one of the bolts (one of the LONG ones, the one at the 10 o'clock position looking from the front) had its tip break off in the front cover under about 5 ft-lbs of torque. Just about the last 1/4" of it I would estimate.

Anyone have any ideas as to how to get this out? It's not easily accessible since it is about 2-2.5" back in the hole where the threads start. I really want to avoid taking the front cover off to get at it if at all possible.

TIA

[Inf]

Could someone post a picture of the OEM water pump mounting hardware? I remember seeing Chloe post it on midwestZ a while back. I need it for a reference to know how long it was and if these are even the correct bolts (darn that PO!)

[2ManyZs]

If you can't see it with the front cover on to drill it out, the only way to do it right would be to remove the front cover. There's a possibility that it was cross threading since only a short piece snapped off and it might not need to be drilled out, but, you ought to chase the threads with a tap to be sure after you get it out. You might get lucky and only need a pair of thin jawed vice grips if the end of the bolt is sticking out of the block far enough.

Think of it as a good preventative maintenance exercise, you'll get to check out the timing chain tensioner and chain closely, replace the cover gasket which has a tendancy to leak a little at the bottom, and replace the front cover seal all in one shot....

Lot of work to do when a simple water pump change was all you needed........

[Ed]

Yup, you have to remove the front cover, what will give you even more room is to remove the radiator. After you get the cover off you can see how much of the bolt is sticking out. If your lucky a pair of vise grips will take it out. If it's in there and your going to do the "drill / easy out" thing then first drill the center of the broken bolt with a 1/8 bit important that you drill in the CENTER, next take the largest size bit that will drill out as much of the broken bolt as you can maybe 1/4 or larger. Be careful not to drill into the threads of the block. Use lots of lubricant (WD-40) then use the easy out. DON'T force it, no more than 5-10 lbs of torque. If it doesn't move heat it up with a torch and try again. The last thing you want is a broken easy out in the hole (Trust me on this). Then like 2manyzs said chase the threads to get it all nice and clean.

Good luck

Edit: try to replace as many of the bolts as you can and put some anti-sieze on the threads.:classic:

[dspillman]

INF,

The Bolt I have is approx..86mm long at base of bolt head

uses a 10mm wrench ,right?

david

[Inf]

Well, I guess i'll be taking the front cover off then

Thanks for the pic dspillman, from the length of the threads that are left it seems pretty likely that a decent amount of the bolt will be sticking out from the block. I looked in with a borescope and did not see where the front cover ended.

[Bambikiller240]

It may not be necessary to tell you this, but others may benefit. This is actually a very common area for considerable corrosion to occur. The bolts can, and do become very weak and soft in this environment of moisture, and dis-similar metals. It is wise to replace all of the the bolts (for a few cents in extra cost) when corrosion extends beyond minor surface rust in order to minimize the chances of something like this from occuring.

Another place to consider replacing bolts in order to minmize headaches, is where the thermostat housing bolts to the cylinder head.

[240Z4me]

A recent exhaust manifold gasket replacement yielded two broken studs for me. What a pain. One broken ez-out(makes you wonder about that name!) later, I had to drill out the head and tap a larger thread, which I hope will hold (lots of thread lock!) If the leak returns, I guess a new head is my only alternative, or maybe that V-8 conversion would finally be justified!