How an intake manifold gasket replacement turned into pulling heads on Olds 307

Man, I haven't been on here in a while. BUT... that's mostly because I've been cruising in the Vista Cruiser rather than talking about it, and, of course, work and life and all that other mess....

I had put off replacing the intake manifold gasket in my 85 Custom Cruiser for a LONG time, but recently got motivated to get back to it because I really miss driving that car. So... I started yanking off components and the MILES UPON MILES of vacuum hoses for the pollution control system as seen in pictures 1 and 2.

Those millions of miles of hoses on this car are enough to deter one from even THINKING bout taking on such a venture. BUT... it must be done. And, to be honest, since a lot of that stuff is obsolete and/or not working, I'm cutting down on a bunch of that crap big time.

Luckily, since I need to keep my carport and utility room areas clear of parts, wagons have a built-in parts storage.

Well, I finally got all the crap disconnected and removed enough of the hoses and wires to finally get to the carb/intake and realized that the intake was FAR TOO cruddy and dirty to attempt to remove it, lest all that junk fall down into the valley of the block, so I had to get to work cleaning that crap off. I sprayed LOTS of purple power on it and went to work with my toothbrush and shop vac.

Then I took a month hiatus or so, because low and behold an issue happened with the Vista Cruiser that needed my immediate attention. Well... a couple issues happened. But that's another story. ={

Well, I finally got up the courage to pull the intake an carb. Unbolting the intake bolts wasn't too bad, and I was almost elated to discover that my efforts had not been in vain because 3 of those bolts came out COVERED IN OIL, in fact, one bolt gushed oil when I pulled it out; meaning that oil was all up in the threads indicating a MASSIVE intake manifold gasket leak. So, expecting this intake to be difficult to pull as it was before in the Vista Cruiser, I got my prybar and was extremely surprised when the intake popped right out! And... its aluminum?!? Wasnt expecting that. So, I got my purple power again and went to work on it with my toothbrush, while going back and forth from the intake to the valley with a scraper and shopvac.

After all that, I deserved a beer.

But during my cleaning of the valley, I noticed an oily sludge that wasn't normal oily sludge. (Pic 8). Brother in law said he believes it was probably some sort of Stopleak, so I began to suspect that the previous owner (I've owned this car for 13 years) may have had a head gasket problem.

My suspicions were confirmed when I decided to pull the valve covers to inspect the rocker arm assemblies. The assemblies themselves looked good, oiled in all the right places, a little bit of gunk on the pushrods but nothing major. The driver's side cover came off without a hitch and looked like the previous owner had some work done to it and when it was replaced, a silicone bead was used in place of a gasket. The passenger side valve cover, though, had a thick, heavy black hard substance for a gasket that broke apart as soon as I moved the valve cover.

And then, I discovered the gem in picture 9- the middle headbolt head snapped right off and resting on top of the head between two valve springs. And only GOD knows how long THAT's been like that. I did mention to the Brolaw that I have had an unexplained slight coolant leak in this car for THIRTEEN YEARS and could never quite pinpoint it. He said this is most likely my biggest culprit combined with that stuff he suspects is a stopleak of some sort.

So... originally, I had started out just wanting to pull the intake, but now it looks like I'll have to unbolt the exhaust and all the FRONT brackets and components and pull the heads as well. I've done this on the Vista Cruiser, which does NOT have miles and miles of pollution control B.S. and it's really not that bad, but on THIS car..... man, I am dreading that. But it has to be done.

I was originally thinking of just leaving it alone, but then I realized that the missing headbolt would eventually probably cause much more than just a slight coolant leak down the line. But... I'm just afraid that pulling the heads will just lead to the discovery of a burned exhaust valve or something like that, and I just DO NOT have the dough to get the heads reworked. I mean... IF I could get a shop to replace my seals if needed, I might do that, because this car has been burning oil, but DAMN, I hate how one thing leads to another in these old cars. But we just love to drive them, so I guess it's worth it.

Any pointers would be appreciated! As far as.... what I should absolutely look for regarding the heads, how much of that pollution control crap I can just delete and thoughts on what that oily sludge is, and how in the WORLD the head of that head bolt came off like that. And.... WHEN?! LOL. Not long ago? 13 years ago? 30 years ago?!!? Lol.

I just wanted to add that before I noticed a surge in idlespeed (stuck in high idle) and suspected that the intake manifold gasket had just failed, this engine ran BEAUTIFULLY. Nice and smooth. Lots of power, too, for a 307 in a station wagon.

 

For how much teardwn you're doing, go get a junkyard engine that has some kind of warranty on it. Swap it out, then you can look at rebuilding over the next few years whilst you enjoy your "cabin cruiser." You can also plan out redoing your induction with a non--CCC carb and perhaps build a bit of mild performance into it. Since removing all the smog crap will make it not original anymore, you also have the chance to find a powerful Rocket 350 or 400 to motivate that cabin cruiser, and back it with a 700R4.

 

You can also look at the thread on "Olds 307 to 350 swap" if you decide to keep the 307, by striking up a convo between you and member zzzizxz. If he decides to pop in another engine, his 307 would be orphaned, and you could strike a mutually--benefitting deal.

 

The Chevy 350 in my Custom Cruiser has an aluminum manifold and had a front coolant crossover leak. It was loosing coolant slowly and you could see it leaking out around the ports, makes a greasy mess all over when the fan blows the coolant back on everything. By the condition of the gasket and corrosion around the ports on the manifold I'm sure it was leaking into the engine slowly too.
If the engine was running fine and shows no sign of the head gasket leaking I'd just put it back together and hope for the best,

 

Well............. first I need a . Okay get those heads off... easy for me to say, and see what kind of mess you find. I'd go from there. If it ran decent maybe just a good cleaning, new gaskets, 30 miles of hoses, and a good tune up is all it will need.Already one more beer and let's get to work!

If you'd checked in more often one of us could have warned you about the broken bolt!

Call Dennis 1tire man, he'll be glad to tell you what to do next. Keep the beer handy!

 

Oh, the beer is handy.

I didn't ever consider dropping another engine in there. That 307 ran just fine with as much power as that car needed up until the fast idle issue.

I'm going to pull those heads and see what I find. It's easier to inspect heads when you've got the valvetrain off, so that's my next step; keeping everything in order and stored in a manner that will make it plain and simple to put back. I'll go ahead and clean the pushrods, but I'm not sure if I should do anything with the lifters. I wouldn't want to collapse a lifter during the cleaning process and have to get a new one that won't be broken in to the cam. Besides, the oil flow looked good from what I could tell from the rocker arms; a nice pool of oil in each arm.

I'm just curious, how would anyone have warned me about the head bolt? From the symptom of a slow coolant leak? I'm just wondering.

Lol. I'm wagonless at the moment. I had a mishap with the Vista Cruiser, and I need to replace rear wheel studs and at the same time, I'm rebuilding the tailgate window components. So I'm kind of bouncing back and forth between the two.

PLENTY of beer is handy!

 

Kegerators are useful when working on old cars. PLENTY of beer on hand.

 

MISHAP?!? How'd you have a mishap?

Hopefully, pulling the head will yield the broken bolt shaft easily (raps knuckles on noggin) "Knock on wood!"

 

Too much beer equals broken bolts!

 

Yeah, it looks like the head bolt snapped off just below the head of the bolt so I'm sure there is enough of the shaft to get a grip on.

Mishap in the Vista Cruiser is a sad story. I was on my way to the carwash and took a back road (thankfully, instead of the interstate!!!) and I didn't really notice any wobbling or anything but next thing I knew, there was a loud "POP!" and my ass was dragging so I stopped immediately. The wheel had popped off and took 2 studs with it, AND put a nice dent in the back panel and tore off the lower part of that panel completely. The lower part isn't too bad (noticeable to a bodyshop guy, but not a passerby), but the dent is pretty nasty looking on what is otherwise a pretty straight body.

The only thing I can think of is that a couple of the lugs had come loose and just allowed the wheel to wobble off. I didn't notice anything except for maybe 5 minutes prior, which I mistook for road conditions. I took a turn and felt a little wobble, but it was coming off of a crappy Louisiana road, so I didn't think too much of it.

Yeah... anyway.

I don't have too many beers when I'm working. Just enough ease to my temper!

 

That's enough to drive a man to drink! On our son's El Camino he had wheel studs break several times. Don't remember why.

 

Because he and machinery don't get along?

 

I had a wheel fall off my '89 Bronco...during rush hour...on a one-lane bridge! Fortunately, it didn't break any lugs, and I had a box of spare lug nuts in the back, so with another guy's floor jack, I got the spare mounted, and moved out of the way. I was grateful to the guys that immediately helped, but all the other angry drivers know where they could shove their middle fingers. Sideways.

 

Don't be intimidated. It's a simple nuts and bolts job to R&R the heads. Dirty and lots of tight/rusty fasteners but it isn't complicated.
If it(head gasket) wasn't leaking with the broken bolt it sure won't with a new gasket and bolt. Take it apart, clean all the mating surfaces well, chase the head bolt holes and be sure they are dry before assembly. Use good gaskets, torque correctly and enjoy the fruits of your labor. Don't overthink it, just do it, you can.
RE junkyard engines and their warranty:
Warranty is worthless as tits on a bull. They know nothing about an engine they sell, odds are it'll run(also leak and be at least a bit tired) if not they'll (maybe ) give you another unknown. Meanwhile you either turn wrenches or pay another to do so, no junkyard will contribute to that. If you buy another engine see and hear it run or buy a known good one.