hgoodwiniii

HI everyone, I'm changing the intake manifold gaskets on my 91. Wouldn't you know it, I'm having trouble with 1 seized up manifold bolt. It's the 1st bolt at the front of the manifold on the driver side. I had to drill/grind the head off to get the intake off. I was hoping I could grab the remaining stem (shown in the picture below) by soaking it with PB Blaster and grip plyers to get it out but it's not moving. Any suggestions on how to get it out without damaging the head? They are the original aluminum heads. Is it ok to try heat? Thanks.

89C4L98

Weld a nut on and carefully use some heat

383vett

Lot of heat and vice grip the thing.

hgoodwiniii

Ok, I'm not a welder so heat and grip pliers it is.

yakmastermax

Torch and vise grips
torch and bolt extractor

Gale Banks 80'

Keep drilling the hole till it breaks all the way threw. Then Heat the Bolt as hot as You can get it. Then walk away and let it cool down. When it cools the Metal will shrink and because you drilled a hole it has somewhere to shrink to. You might need to do this a couple of times. If its still being stubborn start heating the Aluminum around the bolt and turn it will the Aluminum is hot. Aluminum expands quickly.

hgoodwiniii

Ok, thanks Gale Banks 80'; I will try you suggestion. I just hope I don't screw up the head trying to drill all the way through . I tried the heat/vise grips yesterday. The vise grips just keep slipping and spinning the tighter I clamp them down on the part of the bolt sticking up and that part of the bolt sticking up is just pretty much collapsing now.

Gale Banks 80'

Go slow. Heat Cool Heat Cool.

ajp01

Surprising as it sounds, you may also get it moving by trying to tighten it first. Just get it moving to break the corrosion seizing it there, and it may loosen after that.

hgoodwiniii

That's a thought; I'm going over and try it later today; Thanks.

hgoodwiniii

HI everyone, so I'm still working on getting the intake manifold bolt out. I think I'm getting close.

It dawned on me that maybe I should change the head gaskets while I pretty much have the top of my engine torn apart and am changing exhaust gaskets. My car has ~220,000 miles. I've owned it since new and it's never been driven really hard except me just getting in it every now and then. It was running great before I am starting the gasket work to get rid of oil and radiator leaks.

The head that I'm working to get the seized bolt out has a few scuffs and indentions I caused trying to get the seized bolt out. Should I pull the heads? I've heard these C4 (L98) engines lasting up to 300,000 miles. It'll probably take me 15 years to get to that. Any thoughts? Thanks.

ajp01

If it was running well and you're just trying to fix oil / coolant leaks I would leave the heads alone. Unless you have problems with uneven compression, steam in exhaust, etc., and there's no indication of issues related to problems, if it were me I'd leave it.

If the scuffs/dents you caused are not in a critical sealing area near the water jackets (i.e. where the actual gasket sealing beads seat onto the heads) there's no reason to expect they would cause a problem. The FelPro blue gaskets that come in the upper engine gasket kit (manifold, TPI plenum, O-rings, etc) are designed to seal even on "imperfect surfaces" using their lingo, and they do work very well based on my experience with them. Use some GaskaCinch to help the seal (or RTV as some people prefer) and that water jacket area should be fine using the right torque sequence and torque setting.

If you've got a concern over a particular set of scuffs in the head, post a photo and let the forum advise.

IF the valve guide seals have never been replaced on that motor, you will have oil leaking into the combustion chamber and even possibly to the spark plug hole area, plus blue smoke on first startup after sitting. IF that's the case, then I would recommend replacing those valve guide seals and O-rings at the top of the valve stems. 32 years and those valve guide seals will certainly be dunzo. I did mine when I had the top of the motor apart (same way you're doing now) and I'm glad I did them.

hgoodwiniii

Thanks - that's good feedback ajp01. The car has simply been amazing to own over the years so no smoke/steam type issues at all so far. I will post pictures of the head when I'm done getting that bolt out. I will more than likely take your advice and change the valve seats.orings. Thanks.

hgoodwiniii

Hi everyone, either I made good progress on my stuck/broke manifold bolt or I really screwed up. I've attached a photo of what it looks like now along with scuff marks I managed to put on the top of the head around the bolt hole. I ended up drilling, chiseling, and grinding the bolt. The scuffs happened with the drill/dremel slipping around at times. I also broke to bolt extractors so this thing was really stuck for some reason.

I never saw any bolt or hole threads so I'm thinking that I have not drilled/ground out all of the bolt shaft. An old intake manifold bolt will not go into the hole so I sure it is not bigger than original. I did notice what looks like metal (rusted) threaded inserts in the driver /passenger side rear intake manifold and front passenger side intake manifold bolt holes on the heads. I'm assuming there was an insert on the front driver side hole which may be why that bolt seized up. Are these normal? I've never seen them but this is my 1st time working with an aluminum head.

My questions are am I screwed? where do I go from here? Tap a new hole? Heli-Coil? Does it look like the scuff marks will cause me trouble? Thanks.

ajp01

No, it's not normal to have inserts in those holes unless someone put them in there after the car needed them (for some reason). No, I don't think you're screwed because I think those FelPro gaskets with Gaskacinch can probably still seal that surface. The gaskets are a rubber-like silicone-ish looking blue stuff, and they have a bead at the water jacket holes that squishes down under compression load from the bolts. They seal really well even on surfaces that have pitting or damage, which I think yours qualifies.

But - you have drilled out the bolt well and you still have bolt material / insert metal left in there. That, I don't have a good answer for. If it didn't come out before using all that torque you were putting on the bolt, I am concerned that an EasyOut isn't going to get that stuff out of there either because it's so seized in there.

What do the rest of the forum think here?

SH-60B

If I found myself at this point I would continue drilling but with a smaller bit than that. I have also used a small drift and hit the bottom of the hole to try and break the corrosion bond . IDK if that's a blind or through hole into the lifter valley. If it's blind go until you hit aluminum and fill the hole with penetrant oil and give that a few days, it might easy out by then. Removing the head is not a real problem, just time consuming, then what? Bring it to a machine shop to get the remains out I suppose. They'll want to rebuild it and ask you for the other one. What a snowball one stubborn bolt can cause.

FostersPerformance

The bolt is still in there...At this point you can try a left handed drill bit after you heat it up. You mentioned you have a dremel. If you have a small carbide bit that will fit in there, grind 2 slots 180 apart from each other. Then using a punch, try to split the bolt and get the 2 pieces out.

If you have to drill it out and use a heli coil, its not a huge deal.

hgoodwiniii

Ok, thanks for the feedback - I will give get back at it on Sunday. This feels like a disaster but thankfully, it's only one bolt. No idea why those inserts were in there. I do remember having the intake changed under warranty way back in the 90s. Thanks.