I recently put my engine back together, its the 5.7 and have a coolant leak coming from the back of the engine the only thing I can figure is that its the crossover tube on the back of the heads. The washers were pretty beat up. Could that be where the leak is coming from or is there something that I'm missing.

 

Could be head gasket or intake manifold leak. If you really cant see where it's coming from i believe you can add COOLANT dye to help you pinpoint it.

 

I just did both head gaskets. I've looked and looked and the only thing I can come up with is that crossover tube on the cylinder heads. It's possible that it might be coming from the cylinder head but too far back there it's hard to get a good look. The guy who helped put them in also I think threw away those rubber washers on the back where the crossover tube is. And if it was a head gasket wouldn't there be steam or white smoke coming out of the exhaust. and i checked the oil and no signs of being milky.

 

there's your problem

 

I have re-used those rubber washers several times. They have to be there or it will leak. I think NAPA carries them.

 

You have to use the proper bolts and washers for that pipe. Also remember the gaskets between the pipe and block, if you cant find them, make your own.

 

Thanks for your guys input. Just needed to know if the leak was coming from that tube. And i didn't think those washers were that important, which turns out they are. I don't know if all them are on there but I know they were falling apart.

 

Remember, you need FOUR of them - not just two.

 

You might be able to get them from the dealer. I think I got mine from gmpartsdirect when I replaced the steam tube, but shipping would be too much for just the washers. I saw some at AdvanceAuto that were close, but for such a critical part in such a hard to get to place I decided to get the exact part.
Developing a good relationship with your dealer's parts personnel can really help with getting parts for our cars.