Pampered-Z

Sorry if this is the wrong section.

I have a 99 GMC PU W/5.3. Dead stock, 165K and running strong. Last week it started with a slight exhaust leak, what I found is that the back two bolts of the exhaust manifold on the DS are sheared off.

The bolt in the middle might be sticking out enough to get a visegrip or something on it, back one feels even with the head.

With all the miles on the engine I REALLY don't want to pull the head off.

Is this at all common for the bolts to do this? On my 93 LT1 it is common, but the LT1 heads have two bolt holes on the outter ports and after market headers use them. Does the 5.3 head have the same set up, or am I screwed? There isn't enough room to get a drill/easyout in there to remove the broken bolts with the heads on the engine.

Thanks,

veee8

iTrader: (40)

I have seen this on at least a dozen or so trucks. Check the manifolds over real good. I have seen several with cracks. My old local dealership had them in stock! I have seen where the manifold had a buildup of rust, and it finally sheared the bolts from the pressure and thermal expansion. The factory bolts have some sort of threadlocker on them, and are pretty expensive. I use a right angle drill, with left hand drill bits. Starting with a small drill bit, and working your way up. A lot of times they will back right out with just the drill bit. If not an EZ out, or drilling most of it out, then using a punch to break out the last little bit. Proper tools and patience will pay off on this one.

veee8

iTrader: (40)

Pull the front tires, and peek through the wheel wells.

eallanboggs

iTrader: (1)

You'll probably need to pull that head to do this properly. What is it about 165K miles that makes it a problem to pull the heads. You should examine the other side closely too. I use Stage 8 exclusively to keep the headers at home.

GMCtrk

iTrader: (23)

that happened on my swap engine as well. 2 broke off outside and 1 broke off in the head. the 2 on the outside came off with vice grips. The one inside was drilled out.

NemeSS

iTrader: (127)

me too
i have a set of truck heads stting in my garage with 2 bolts broke flush to the head
one is actually in about a 1/8in. in
sux

Pampered-Z

Only because me being me, once I start pulling parts off I won't be able to leave well-enough alone and I'll start replacing stuff like the timing chain, oil pump, and then port the heads, add a cam....

Then I'll end up blowing the trans and such!


So I really need to leave the head on!

Thank you all for your help.

John

stricker76

We do dozens of these a month on 5.3L's and mostly 6.0L's in 1-ton landscape trucks. Normally end up welding nuts onto them to get them out. Replace the manifold while your there. Usually snap because the manifolds start to warp and put excess strain on the rear port bolts. Aftermarket manifolds are cheap anyhow.

eallanboggs

iTrader: (1)

If warpage is a problem and these bolts are being sheared off due to expansion and contraction of the header flange(as opposed to breaking off due to vibration from loose header bolts) you might consider clear drilling the flange bolt holes a little to prevent this from happening again in the futrure. Apparently this is more of a problem in northern climates.