Hey guys, so I've got a bit of a concern. I have been doing some work on my 02 Z06 (replacing the known bad valve springs) and it's been quite a nightmare of a job...not to go into too much detail, but I thought I had to pull the head on the drivers side. I accidentally dropped something in there while trying to find TDC on cylinder 3, and began the process of taking the head off. Half-way thru, we came up with the idea to take a telescoping magnet pen, cut off the magnet head, and solder it to a thick wire. This actually allowed us to get the small tool we were using to gauge weather or not the cylinder was at TDC.

At the point we got this, we were relieved to not have to finish pulling the head off, and then started to throw everything back together. I purchased new OEM GM head bolts, and torqued them down to spec using an angle meter and all seems good. The car is now back together, with the exception of the plugs and coils back on..and I ran compression on each cylinder, which checked out at between 185-190psi.

Here's what I didn't realize I needed to do tho. After reading a bunch of DIY head removals, I realized that we did not clean out the head bolt holes in the block. Since we didn't remove the head, and never even separated it from the block, it didn't even occur to us that this was something that had to be done. It sounds like some coolant can "splash" into the holes when you actually pull the head off and break the gasket seal. My concern is, even tho I didn't pull the head, I took all the bolts out (except for the furthest small bolts up by the intake manifold), and it allowed for a VERY small amount of coolant to leak out, leaving a very small puddle on the garage floor. It was nothing like the amount that falls out when you actually pull the head. Very tiny puddle, enough to be soaked up by one piece of paper towel. So i'm not sure what the odds are of some coolant even making it into the head bolt holes, especially with the gasket still being in place and all.

So here's my question..do I need to disassemble everything and pull the head to make sure those bolt holes are clean? The new bolts are already torqued down and the head gasket is sealed with no leaks..so I'm not sure if this is a concern. If i pulled the head, this is a no-brainer, but I don't want to go through all that work if people who know more than me, don't think it's necessary.

I heard that if there's any liquid in the holes, the heat from the engine can cause the bolts to expand and lead to cracks in the block. I just really don't think anything got in there...but I'm not a pro and am just taking a guess.

Let me know what you experienced guys think about this.

Thanks!!

 

I definitely would, it sucks to pull the head back off but a cracked block would suck a ton more! When I did my heads/cam swap I spent probably too much time making sure all the holes are dry and free of dirt & crap.

 

I would wait till you get more input before I pull it. I think the cleaning process is to insure that when you install the new bolts it doesn't crack the block. If the bolts are already installed there might not be a reason to remove it.

 

I would sleep better after pulling my head and checking things out. Don't like to lay my head on the pillow. And all I can hear is that ticking time bomb. Tick! Tick! Tick! Tick! Boooom!

And yes I can see how hydraulic pressure from perched water could cause cracks when you tighten the head bolts. But still I would want to check things out thoroughly.

Wow. It's nice not being the one told to get his head examined.

 

I would have to agree change the gaskets and bolts. I like to sleep not worrying about the car. There is better things to do in bed

 

PAUL hit the nail on the head!! If liquid gets into the blind hole and you force the bolt into the hole,,, THE DMAGE IS ALREADY DONE and theres NOTHING you can do about it.

So,, if it were me, I would let sleeping dogs lay or lie (how ever you want to say it)

IF you decide you cant live without pulling the heads,, ( I really don't recommend it) I would reinstall ARP HEAD STUDS instead if using the OEM bolts.

Bill

 

If you were able to easily thread the bolts into the hole until they were almost all the way in, I dont believe that you have anything to worry about. IF,,,,,,,,,,,,,,,,,,,,,,,, you had to force the bolt into the hole, then you may have an issue.

 

Nope, it went in easily, just that last 90' turn on the bolts required some definite muscle...but everything I have been reading says that's to be expected.

I'd think the damage would already be done..thanks for the input so far guys.

 

If the bolts went in EASY,,,,,, I believe you dodged a BIG BULLET! You would have had a hell of a time getting it to seat to get to that last 90!

Bill

 

Man I sure hope you're right!

i just jacked the car back up and spent about an hour looking at the block with as many angles as I could - zero cracks that I can see anywhere. Of course, this only counts for the lower 5 bolts. The block looks just fine from what the eye could see.

Also - a helpful trick to see in those difficult angles. Use your cellphone, go into video-mode, and turn the flash on. This'll let you use it almost as a "scope". Sure helped me a lot tonight!

 

I think you are fine.
When guys bust blocks due to coolant in the holes, they report a loud "pop" sound while torquing.

Ron