Help!!! Advice needed, 4.3 liter engine head gasket in a 96 Astro van

Have him spring for a Alldata subscription for the van. At least you will have some sort of resource with diagrams for the van, and since he's a 'puter guy he should have a wireless laptop for easy fender side viewing.

THere is a bigger concern hear. Head gaskets on these engines do not just pop or fail. THere is always a reason. Usually it is from low coolant or overheating and the head warps and gasket blows. You want to pull bot heads and have them checked for flatness at a machine shop and trued if need be before you put it back togeher. Do not skip this step.

----------------- TheSnoMan.com

As someone else already pointed out go ahead and pull both the seats and cover the front in something you don't want anymore. I used cheap k-mart blankets and just threw them out when done.

The engine is just an engine... Nothing really special or different that will throw a person that with your experience will get hung up on. Be prepared for more than normal amount of crap to break that you weren't expecting. It gets awful hot under there and things seem to age more I would expect from a similar engine in a normal application. Also be prepared for your arms to look like you were at war with a gang of alleys cats. There is no working room in there.

Steve B.

Birdbrain

Care to elaborate? Is Mike (i.e. me) or snoman the birdbrain?

Do you know something I should be doing or not doing? I'm the first to admit that I do not know anything about a 4.3 engine, and am asking for help ! The family consists of dad, mom and 4 kids and 2 vehicles. Mom and the

(and I really appreciate all the suggestions above - I'm printing everything and taking them with me...

Currently I'm budgeting 3 days for the job/visit, maybe 4 if the machine shop is slow getting the heads back i.e. delays the process. Current plans are to do the following during the "down time" while the heads are out at the machine shop...

on Sunday 28 October 2007 12:15 am, someone posing as snipped-for-privacy@gmail.com took a rock and etched into the cave:

Um, the big thing you're going to run into is that the van has the engine tucked way in the back. You might have trouble getting to things.

Snoman

Why he felt the need to parrot his same old drool when you had already mentioned having the heads checked/reworked is anyones guess.

I highly advise using a Fel-Pro MS98002T intake manifold gasket set on this application, this set is a better design that addresses the inherent weak spot of the OEM manifold gaskets which were very prone to failure. (and may well be the root cause of the overheat) Also, keep the injectors wet once disassembled; when you disconnect the fuel lines at the left rear corner of the engine, cap the lines on the manifold side. If the injectors are allowed to dry out, there is a very good chance that they will stick and cause a misfire.

Good luck with your project.

No you mean Neil is the bird brain. Head gasket do not just fail for no reason and if you think they do you are a bird brain.

There was a design defect with Intake gasket that GM rediesigned in late 2005. It effected the 4.3 and 5.7 Vortec motors. I personall had one fail on my 2000 5.7 under warranty at 29K miles and again out of warranty at 38K miles. They fixed it for free out of warranty and promised me that if it ever leaks again they will fix it for free. They said last repair had new gasket style. BTW truck only has a little over 42K today

You will need good luck if you follow Neils advise and do not varify that heads are flat. That head gasket is clamped between to big pieces of cast iron and the only way it is going to block is if one of the surfaces warps and changes pressure on it. (or you supercharge it on over boost engine a lot too). SOme time they can warp with heat and straight out with they cool but NEVER change a head gasket on any engine that has blown one without check head for flatness or for etching from hot gasses after it blew.

----------------- TheSnoMan.com

The OP realizes that genius, that's why he stated in his first post that he was going to take the heads to a machine shop and have them checked.

Do you not read what people post, or is it just a lack of comprehension?

You going to deny the plausibility of the computer programmer had a leaking intake gasket and ran the coolant low resulting in what is now SUSPECTED to be a blown head gasket?

GMs redesign sucks. The Fel-Pro gaskets are much better.

The defect effects ALL GM V engines. 3.1, 3.4, 3.8, 4.3, 5.0, 5.7.

IOWs, you've never done the job, even on your own truck.

Hey asshole, where did I tell him not to verify that the heads were flat? (use all the screen space you need to show the citation)

You mean 'two' big pieces?

Gotta love these tangents you go off on... Supercharged?? W-T-F?

Yes birdbrain, this should be mentioned six or seven more times, even though the OP knows to (and has stated that he will) do it anyway.

I have the exact same vehicle (purchased new). I have also done the exact same thing to it as you are fixing to do. I have read all the other threads and you have been given a load of good advice. Here is what I found when I did this on my van at about 117K.

1. The 4.3 is basically a small block chevy v-8 with two cylinders whacked off. If you have worked one the other should not be a problem.
2. Mine started as the intake gasket leak. Kept adding coolant as I was dreading working in the tight space. The comment that your arms will look like cats have attacked them are true. Sharp metal and corners everywhere. You will be working mostly inside the van so (like the others have said) pull both front seats and cover the floor. I put down plastic first (this van is my wife's primary and has been kept pretty clean), covered that with cardboard, and then put blankets on top. Maybe overkill but laying on the floor to work on the van was a lot more comfortable.
3. There is a special intake gasket (again mentioned in another thread) that is a must. I hard a hard time locating in town as most part stores want to sell you what they have. I ended up ordering from rockauto.com.
4. The advice on the fuel injectors is true. I learned the hard way and ended up replacing the entire spider assembly. There is a newer upgrade to the OE model out there so if this happens go for that one. I believe that my costs were about 0 to 5. I got mine at a local NAPA store (could not wait the additional downtime on internet ordering to save the bucks). As a plus once I replaced the assembly the van is now getting better mileage.
5. You will strip the front of the engine. Does it have AC? If so, I did mine without breaking any connections. I wired the compressor assembly straight up from the motor to something under the dash. I do not remember what I wired it to but it held the entire time.
6. I replaced the fan clutch, idler pulley, thermostat, all vacuum lines, heater hoses (does the van have rear heat?)(easy to get to them now), oil sending unit (leaking), and basically any thing that I felt would not last another 75 to 100K. Another thing on removing the fan clutch. I used a large (14") crescent wrench as I did not have an open end that size. It runs in my mind that this is reverse thread due to engine rotation. Also when I put mine back together I did not tighten it near as what it was from the factory. Engine rotation will always tend to tighten it so I felt OK at just "very snug".
7. It took me two solid days to take apart and put back together. 1 day downtime at the machine shop. When you go to put back together you will need help from someone. I found it easiest to have one person up front and me inside. We worked together at setting the heads and intake manifold.
8. Plastic zip lock bags, I used a bunch of them. I would take a permanent marker and write on the bag what the bolts went to. I then placed them in order, reversing them when going back together. Kind of kept me in proper sequence.
9. Distributor, before you remove it mark the housing position on the engine block. Then mark the rotor position on the manifold. The computer sets the timing so if you get it back to where it was originally it will work.
10. As someone else mentioned heat is a killer under here. I ended up replacing the ign coil, new wires, cap, rotor, and other items related. It was way easy for me to spend my own money (probably overkill but I do not want my wife stranded by a part that I could easily replace now).
11. If you have good mechanical common sense this project will not be a major pain.

Take Care, GM

Oh mann...this is a scary thread. I have a 98 Astro that leaks coolant but I haven't had a chance to investigate where from. It leaks it out onto the garage floor and appears to be coming from to front of the engine on the passenger side. It seems to leak about a quart and then stops leaking...kinda weird...and like GM I've been adding coolant every so often. So far I haven't seen any oil in water or vice-versa...I wonder if it could be something besides a manifold gasket? It only has

You just like to be a troll and cause trouble. I was telling them SOP of gasket repair.

Yes I do think you lack reasoning and comprehension...

Where are you going with this Troll??? I said overheating or low coolant earlier did I not?

New design is a lot better

Not really but then a Troll would not likely know this. The reason there was a big problem with 4.3 and 5.7 Vortec motors is because when GM went from TBI to MPI thay changed bolting of intake to engine (example on 5.7 they stopped using center 4 bolts to secure it) and the manifold flexed more in heating and cooling cycle and strained gaskets plus GM used a cheap plastic design for a while too. Intake gasket problems with TBI engines where of a different nature and 3.1,

Actuall I have rebuild a lot of engine and valve jobs and intake gasket changes but why change it when GM will pay to have it done?? Is this a Troll thing? BTW, I was planning to change mine when GM offered to do it for free and free repair if it ever leaks again and only a foolish troll would pass that one up.

tisk tisk, Troll loosing temper. Remember you started this not me....

I guess your troll brain get lost here and cannot rationalize that the block is a big piece of cast iron and so is head.

Another Troll responce, I was stating the reason why they fail in service. I dod not say he had a super on his. I need to remember when you talk to a Troll you have to keep it simple sometimes.

Yes I am sure he sees who has a temper problem here.

----------------- TheSnoMan.com

Uh-huh.. Seems he already had that figured out with out you reinforcing it.

Parroting what someone else has already said shows reasoning and comprehension, eh?

The OP said he was having the heads checked earlier did he not?

By your own admission, the redesign failed in your truck after 9000 miles.

Yes, really. Same gasket architecture, same reason for failure.

I guess you wouldn't.

What about the 5.0, are you saying that that engine didn't suffer intake gasket failures as the 4.3 and 5.7 did? Or is this just your armchair expertise showing thru again?

Just like the Ford Windsor engines which strangely don't suffer intake gasket failures any worse that the pre-Vortec Chevies.

Um, Mr. Genius, the coolant leaks are not in the center of the manifold where the bolts were eliminated, they leak at the ends where there are two (note spelling) bolts per coolant passage. If (big if) your missing bolt, flexing manifold theory were correct, these engines would have a history of driveability problems from vacuum leaks into the lifter valley and oil consumption problems from the leaks allowing oil to migrate into the intake manifold from the lifter valley.

Bingo!

Um, no. They leaked in the exact same place in the exact same manner. Only differences were; it usually took longer before they began leaking and the old gaskets were harder to scrape off.

They most certainly are.

The Buick 3.8/3800 isn't based on a modified 40 year old design?

You don't know your ass from a hole in the ground.

Oh, FYI, Buick didn't eliminate any bolts from the center of the manifold on the 3.8/3800 engines yet the gaskets still fail.

Looks like your "a lot better" redesigned gaskets only last 9000 miles. Why don't you give the OP a break and stop recommending parts that are going to fail and cause him to do the job over again.

Because better parts would be available, because someone isn't too lazy to do it, because someone has the skill sets to do it, because self respect prevents them from whining about an out of warranty failure.

Certainly not, it's a laugh at you thing.

GM "offered?" They have people that just call around and ask if people would like a free set of defective intake manifold gaskets, huh?

You think "free" means good?

So, you can't provide a cite of me telling him not to verify that the heads are flat. IOWs, more of your made up bull shit, which better fits the definition of "troll" than anything I've posted.

But where are these big pieces going [to]?

How can that be a reason [they] fail when this truck doesn't have a supercharger to begin with?

So why even bring it up other than your insane need to fill space with meaningless and irrelevant tripe?

No, you just need to remember to stick to the subject when you actually have something useful to offer and resist the urge to add extraneous filler material.

That would be the guy posting non-relevant, inadequate filler material.

snipped-for-privacy@gmail.com wrote: Posted to alt.trucks.chevy, rec.autos.tech, alt.autos.4x4.chevy- trucks

Subject: Help!!! Advice needed, 4.3 liter engine head gasket in a 96 Astro van

Background...

At first I was going to suggest just buying another Van as it might be cheaper and definitely easier; but I was surprised at these vans resell value. If initial estimates for fixing the old van are near $1000, it might be better to just buy another van. I did a quick search on Craigslist in my area (North Texas) and found a 2000 model with an asking price $2650:

I have a 4.3L engine in my 1995 blazer, and so far have not had the water leak problems. I have had them in my 1998 Suburban, however, and had it repaired 5 years ago. My mechanic suggested using the old green anti-freeze as he has the theory that the new dexcool stuff contributes to the water leak problem. So far his theory is holding up; we've put 75000+ miles over the last 5 years and no problems. BTW, my 1995 blazer never used the dexcool; it was just before dexcool was released. However, a week after the repair and switching over to the green antifreeze, the water pump started leaking... very badly. My mechanic said that it didn't surprise him, and it was because the dexcool coats the inner parts of the pump. As the dexcool desolve, the coating that was blocking leaks goes away. I was dissappointed that he didn't tell me that before doing the job so that the pump could have been replaced at the same time (with very little extra effort). So I decided to replace the pump myself instead of hiring him; it was an easy job anyway. BTW, the actual reason for the intake manifold leak problem is because GM redesigned the bolts to go in at an angle relative to the manifold. Why they decided to change the design is beyond me; the perpendicular design was used for decades and was proven. It almost makes you think they wanted bad design.

Good luck with your repairs.

Best Regards,

John Hermann

Hey Neil, just wanted you to remember that you are only pissing in the wind with this one.

Jinx, You Owe Me A Coke!

Toyota MDT in MO

Your problem sounds more like a bad water pump.

Bob

I beg to differ... ... just as I was reading this, Favre threw an incredible touchdown pass.

Am I coming down there to buy you one or are you coming up here?

Take Paypal?