97 5.7 vortec intake issues

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true95w/t

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Just bought a 97 extended cab with the vortec 5.7. I got it from a friend for 400. It has sat for a year. I bought it so I can finish tt-ing my 00 yukon.
No coolant so I added water. It started leaking out around the upper intake manifold. It's also smoking bad which after watching a YouTube truck doctor vid , it's smoking because intake dumping water into cylinders. So I guess my question is..... can I simply plan on doing intake manifold gaskets or once it's that bad do I need entire new intake manifold? I need to do this as cheap as possibly because the truck needs other work and only reason I bought it is because I needed a backseat to pick my nieces up when their parents both work.
Any insight and assistance is very much appreciated. I am very good on the 95 tbi motor in my old truck and have learned a ton about the ls motors but I have never owned or worked on a vortec 5.7.
I also tried posting on fullsizechevy but their sight is messed waiting on new software I guess


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east302

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How does the oil look? Intake leaks usually dump coolant into the crankcase. Head gasket leak would put coolant into the combustion chamber.

You see coolant between the lower and upper intakes? The gaskets would leak further down...right where the lower intake sits on the block. You sure you don't just have a water pump hose leaking and spraying back? A coolant pressure test may be in order.

If you do have leaking intake gaskets, I'd be tempted to just do the gaskets, as that's usually what has failed. A new manifold is around $400, and you don't really know what you got from a salvage yard until you do all the work to put it on.

I suppose you could take a straight-edge to it once you take it off, see if it's obviously warped or something.

Good luck with getting the stupid heater hose fitting out of the intake. It's liable to break, so just be careful. A lot of people replace it with a barbed hose fitting (1/2" NPT x 3/4" hose). This is what I used:

https://www.spectreperformance.com/mobile/product.aspx?prod=5954

The upper intake is some kind of plastic/composite. Not expensive to replace if it is somehow damaged. Maybe $70?

While you're in there, and if you have $300 burning a hole in your pocket, it's a perfect time to swap the injectors to the upgraded design. Much better throttle response.

https://www.amazon.com/ACDelco-217-3029-Original-Equipment-Injector/dp/B000NW8EU8

You'll need a good scanner to set the distributor camshaft position sensor offset (CMP Retard) or download an app (DashCommand or CarGaugePro) and use a Bluetooth OBD adapter...maybe $50 total for the download plus adapter.

To set it, loosen the distributor hold down clamp, bring it to around 1100-rpm and turn the distributor to set the retard per the scanner reading. It should be zero degrees, plus or minus two.
 
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