96 4.3 L ?

vehicle is a 96 Astro van, 4.3 L, engine code W, 130 K on engine. On the drivers side of the engine is a large aluminum mounting bracket that holds the AC and PS units. The engine has developed a rather fast drip of antifreeze from behind this bracket. All attempts to see where it is coming from behind this is futile. The next step is to pull the bracket and related items off to locate the leak. The hoses, water pump, t-stat housing, etc all are visible and are not leaking. My gut feeling is the only thing left is an intake manifold leak (hope not). Anybody have any insight into this?

TIA GM

Reply to
GM
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Preliminary diagnosis indicates further diagnosis is needed.

Could be intake. Could. Possibly.

My suggestion, drop die into the radiator and use an UV lamp to pinpoint the leak.

Available at all fine autoparts stores everywhere. (NAPA)

~:~ MarshMonster ~would loan you his lamp......but it's growing season ~ ~:~

Reply to
Marsh Monster

That would be a leaking intake manifold gasket.

Reply to
aarcuda69062

Pulled the bracket this morning. The leak is from the front corner of the intake manifold. Also when I pulled the doghouse cover I see a minor seep also from the back of the manifold. This is an Astro van and the work area is quite cramped. Any body have any hints or advice to make this a little easier. I have already decided that I will pull the front passenger out to give me elbow room inside the van. Any other ideas? Also, is this a problem area to get re-sealed on these motors? Any comments or advice on a replacement gasket set that is high quality. I don't want to pull this sucker apart again. TIA GM

Reply to
GM

Not much I can tell you to make the job easier, cramped quarters are cramped quarters. Move as much as you can out of the way before you lift the manifold off. Hold any harnesses that may be in the way back with bungie straps.

The best gasket set IMO is the Fel-Pro part # MS98002T, it is a complete gasket set for the job and although priced much higher than the competitors, when you see it, you'll know why.

Before you start disassembly, aim the ignition rotor to somewhere that will be easy to remember (straight forward or backward), you absolutely MUST re-install the distributor to this position when done!

Clean all manifold bolt threads in a wire wheel and apply red Loctite to the threads when installing, the bolt torque values are very low, you need the Loctite to hold that torque and to seal the threads. Low torque values mean either a 1/4" drive inch-pound torque wrench or an electronic 3/8" drive, at least three passes around all manifold bolts on final torque. Gaskets go on dry except for the next item.

Permatex "The Right Stuff" on the manifold/block end seals.

If there are any quick disconnect fittings for the heater hoses screwed into the manifold, now is the time to swap 'em for some steel replacements from Dorman.

I don't usually separate the plastic plenum from the lower manifold unless there is a problem such as a vacuum leak.

Do plug the fuel rail fittings when you disconnect the fuel lines, you want to keep the fuel injectors wet inside to avoid missfires from dried varnish sticking the poppets.

The manifold can be R&Red if you remove just one valve cover, even though the Fel-Pro kit comes with two valve cover gaskets.

There is no ignition timing to re-set when done, the timing is via the crankshaft sensor and as long as the distributor is re-installed exactly as it came out, everything will be fine and there shouldn't be any SES lights.

I strongly advise against using any sort of powered abrasive devices such a Roloc pads to clean the gasket surfaces, everything should clean up nicely with a single edge razor blade.

Reply to
aarcuda69062

Did you say RED loctite? Will those bolts ever come out again? I think I would go with blue (if any).

Reply to
ShoeSalesman

Yes.

Yes.

It's a free country.

Reply to
aarcuda69062

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Shoe, I agree with Cuda, use the red.

I don't even bother with anything other than the red anymore because it works. The fasteners will come off later on if need be, but they won't come off if they need not be.

any whooo.......

m/o

~:~ Marsh ~:~

Reply to
Marsh Monster

Yep, I guess if the bolts and holes aren't very clean it would be good. There's no way I would use red if they were perfectly clean. You would have to use a torch or risk breaking something otherwise to get it apart later.(or at least make it a *major* bitch to loosen)

Reply to
ShoeSalesman

Thanks to all who replied. I have made up my mind based upon the simple, common sense advice I received. Also I have used the "Red Loctite" on my 82 GMC that had a problem with the darn flywheel bolts coming loose. I had them out after red.

The advice is simple and straightforward. The only item that I may have a concern about is the "plugging the fuel rails" to keep the injectors wet. I understand the reason why, but would it be possible to clean them once the manifold is off thus avoiding any future problems. I have had this vehicle since new and have never had any problems as it relates to the injectors. Again, TIA GM

Reply to
GM

how bout this. Get some injector cleaner. After your repairs are done fill the fuel rail/line with the cleaner. Dump the rest (if any) in the tank. This way on your first start up you will get a nice concentrated dose of cleaner running through the injectors. Oh, and be very careful not to get dirt in it in the process.

Reply to
ShoeSalesman

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