My 1987 Two Door Crown Victoria AKA THE BROWN BLOB

[gadget73]

You'd think so. The lower intake is something like 25 ft-lb, which isn't nearly enough to bust one. I've recycled my factory bolts a bunch of times now, and none of those have shown signs of stress. Hell, those bolts have been used to carry the entire weight of the engine at least twice.

[packman]

Carried engine and trans with my intake; and that was with my Dad wiggling the engine to find wires that I failed to disconnect. Though, newly manufactured bolts may be different. I only replaced my calipers 4 years ago; and yet the caliper bolt snapped; despite the grade 8 marking on the bolt head :-/

Dave, I hope that when you replace that bolt, your coolant issue is over. Even though it is late in the season.

[gadget73]

Grade 8 just means its hard and has a higher tensile strength than lower grade bolts. If you really look close at the break surface, you can analyze the failure mode, whether it was a tension failure, a torsion (twisting) failure, or a shear failure. Depending on the material, you may also be able to see if its a corrosion failure, though for recent intake bolts I'd say that is unlikely. On a caliper, they do see salt and water so corrosion is possible.

[His Royal Ghostliness]

Gadget, yeah I thought intake bolt at first as well, but I've dealt with a few cars with those rear intake bolts sheared off and none of them ever really pissed coolant, just wept some. Even more so the case if RTV was used on both sides of the gaskets around the coolant ports, once that grey shit sets properly you can later stretch it some and it still won't break the seal. Could still be an intake bolt of course, but in no way should it be a source for such massive and rapid coolant loss. Same would hold truth for a lower head bolt as well, there will be compression loss and coolant weeping out but certainly should not just gush out like garden hose.

[87gtVIC]

Lower head bolt is the culprit. Way in the back corner near cylinder number 4.

Plans are to pull that head and slap in new head bolts, headgasket as well as all the other gaskets sitting above it....lower intake etc. New coolant and an oil change.

Hooking up the coolant pressure tester got the coolant to push out of that location. Lots of witness marks were visible from inspecting the head to block mating area even before hooking up the tester.

I don't know what the hell happened but happy it aint the core/freeze plugs.

Dissassembly will take place......I don't know yet. Away for work next week and then things get busy for thanksgiving day parade.

Will order up all the bits I need in the meantime and go from there.

[His Royal Ghostliness]

Well that was anti-climactic Kidding, glad it ain't the freeze plugs. Does make one wonder tho, why did this thing let go? I mean it certainly isn't the first time that's happened, even with ARPs, but still. I'm sure you followed the torque spec, but for which head bolts - TTY or non-TTY? Or does ARP have their own numbers they want you to use?

[gadget73]

I have seen that bolt let go on stock engines. Original old bolt, and the engine was hot, then washed. Cold shock may have done it. Should not happen with new bolts though.

Dumb question but is the torque wrench reliable? I have halfass calibrated them myself before using a known weight and a measuring tape to figure it out. Its perhaps not dead nuts but its close enough to know if there is a serious issue.

[87gtVIC]

Well that was anti-climactic Kidding, glad it ain't the freeze plugs. Does make one wonder tho, why did this thing let go? I mean it certainly isn't the first time that's happened, even with ARPs, but still. I'm sure you followed the torque spec, but for which head bolts - TTY or non-TTY? Or does ARP have their own numbers they want you to use?

I followed whatever the specs were for the bolts and cylinder head. All was purchased as a part of a kit meaning to work together.

I have seen that bolt let go on stock engines. Original old bolt, and the engine was hot, then washed. Cold shock may have done it. Should not happen with new bolts though.

Dumb question but is the torque wrench reliable? I have halfass calibrated them myself before using a known weight and a measuring tape to figure it out. Its perhaps not dead nuts but its close enough to know if there is a serious issue.

No clue if the torque wrench is reliable. I have three! All stored with torque settings at zero.


I will admit to witnessing a very minor oil leak back at that location over a 1000 miles ago and snugging up on that bolt some. Could be the reason for what is going on now!? Was just a matter of time before it decided to let go?

Ill see whats going on once the head is removed.

[gadget73]

maybe, but not really sure. Were the threads oiled when you assembled it? Usually those torque values are assuming the threads have some oil on them. It can fetch up otherwise. Usually that won't hurt the bolt any, but you end up with less actual clamping force if the bolt gets tight before its pulled fully down. Could explain the leak. I've also had trouble with the bolts hitting torque before being actually tight when there was shite down in the holes in the block. I run a tap down there to make sure its all clean when I have to pull heads off. A block from the machine shop should already be good but you never know.

[87gtVIC]

I know the washers were oiled as per the directions. Also, as per directions, the bolts have thread sealer on them when installed. I have a nice tap set I intend to put to use once the whole magillah is removed.

[His Royal Ghostliness]

Correct on thread-sealing those bottom head bolts, no oil should be used on their threads (or the engine block's), just up at the washers. I'm guessing dirty engine block thread, down towards the bottom. I do wonder how you plan on going about removing the broken bolt part out of the block tho, drill and EZ-out it?

Also retorquing head bolts is something that is recommended to be done after the engine's been run for a while, obviously most of the time it never happens as once the bitch is put together there's no access to most if any of them, but still, you snugging that bolt down is unlikely to have cause it to shear, as long as you didn't go big diesel gorilla on it. But seeing how the oil passages there are not pressurized I'm gonna venture a guess that the head gasket had never sealed properly there to begin with, obviously it sealed around the cylinder cause of that compression ring but there must have been something preventing the head from clamping down onto the gasket properly outside the cylinder.

[87gtVIC]

I'll know how to attack the broken in bit once the head is removed.

[His Royal Ghostliness]

When you get there, if you do not have any part of the bolt sticking out past the block's deck, I would suggest you use left-hand (reverse-rotation) drill bits do make the hole for the EZ-out tool. With a bit of luck the pressure from that drill bit alone will walk the bolt out for you and you won't need to actually use the EZ-out. I would recommend against standard right-hand drill bits as those may actually thread the bolt in deeper, obviously don't want that to happen.

Just throwing ideas your way so you know what options are out there to explore.

[87gtVIC]

Much appreciated. I have a set of the lefty drill bits around to give her ago when the time presents itself.

[gadget73]

If it snapped, it'll probably back out very easily. Its not seized in from rust or anything.

thread sealer, yeah that sounds right. I think I used plumber's teflon pipe dope on mine. Either way, it doesn't go in dry.