Loud pop and now its missing BAD!!

[Broncoguy]

Ok, so I am talking about the 99 in my sig.
I was pulling an empty car trailer up the hill out of town, foot on the floor in fourth gear, and and all the sudden POP, then it is missing real bad. I pulled over to check intercooler boots, all fine. They shouldn't cause a miss anyway I wouldn't think.

Limped it home and started checking it out, Results;

Oil looks fine and is full.
Antifreeze looks and smells normal.
No smoke out the exhaust of any color.

Next step: AE shows

Cylinder contribution balance faults on cylinders 1+2

Buzz test passes
ICP pressure is 492 at Idle and 800 at 1500rpm

Rotational velocity test results:
1= 9.1
2= 2.8
3= .9
4= .4
5,6,7,+8 all show .0

Obviously the problem appears to be in cylinder 1, and I guess my next step should be to pull the valve cover and do a compression test.

Sorry about the long post. Tryin to give as much detail as possible.
Any other suggestions are greatly appreciated. Thanks in advance.

[Cory S]

man wish i could help. good luck! free bump

[Broncoguy]

Needin some help

[bigwhite7.3stroker]

Dang man that sucks Good Luck on the repair

[Broncoguy]

Well, pulled both valve covers to do a compression test and found 1 bent and 1 completely broken push rod, same cylinder.

Now my question is what broke the pushrods? Doesn't seem like something that should just happen.

I need to get a longer compression test fitting before I can do any compression testing.

Only other thing I have discovered so far is that the valve's seem to be hitting something when I try to compress them. Hopefully a piston didn't come apart or something.

Anyway, there's the update, anybody that can shed some light on the situation or share similar past experiences would be appreciated.

Doesn't look good at this point.

[Broncoguy]

So how common is it for a 7.3 to break a piston or valve? I am starting to think one or the other is the cause of my problem. I say this because I cannot move either of the valves that are sporting the broken pushrods. Anyway, just curious if anyone else has ecountered similar problems.

Guess I'll let you all know what I find once I get the heads off.

[Tyler]

Maybe the rod was bent and changed timing on that cylinder a bit and the piston hit the valve and bent the spring? Kind of weird but maybe it could happen, or I could be totally wrong.

[cowboyupamrka]

that sucks. no problems here, sorry i cant help. hopefully someone can shed some light.

[ford_trck]

Yikes heres a bump atleast

[Broncoguy]

So who knows a good place (Internet or not) to buy the specialty tools needed for the 7.3. I need an extension or something for my compression tester since the glow plug is too far down in the head to get my gauge on. I am also contemplating changing out the injector cups (since I am going to have the heads off anyway) and I here that takes a special tool too.

Any sources or cheap homemade solutions would be appreciated.