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3.4l Head Crack


jnj1181
05-17-2010, 11:22 AM
1999 3.4l v-6. 1 head has a barely visible crack between the valves on 1 cylinder. Is this something that should be replaced?

maxwedge
05-17-2010, 11:59 AM
Welcome to AF. What is the alternative? You cannot reuse a cracked head!

MrPbody
05-17-2010, 12:48 PM
Iron head or aluminum? Iron heads ARE very difficult to repair, making it much less expensive to replace it. The same heads were used on 2.8 and 3.1, as well as 3.4. The aluminum head, however, can be repaired relatively easily.

If this is a "twin cam" 3.4, you probably would have a rough time finding another. If it's the canted-valve OHV version, repair it or replace it.

If you simply can't FIND another OR someone to help repair it, PM me and we'll hook you up.

Jim

jnj1181
05-17-2010, 02:19 PM
Thanks guys, thats what I thought, just wanted to make sure.

uspres2020
06-16-2010, 11:09 AM
Is it possible to repair a crack on an aluminum head as I think I am dealing with one right now with air constantly reappearing in my coolant causing the car to heat up and overflow the expansion tank.

Does anyone have a stop leak that they recommend that could work for such a situation. I have already replaced all the gaskets with the help of a mechanic friend and we did not see any cracks or signs of warpage but some are so minscule that they can not be seen and I am not sure what else could be causing my issue.

maxwedge
06-16-2010, 11:32 AM
Nice to know what car/engine here. Also if the head were cracked and combustion gas was entering the cooling system, the rad hoses would get pressurized shortly after running the engine from a cold start.

uspres2020
06-16-2010, 12:42 PM
Its a 99 grand am. There is a whole thread under the grand am section called overheating about it.

Do you mean the rad hoses to the expansion tank because I don't believe that they have been getting stiff right away like that.

In a couple of hours I am going to try to do a pressure test on the system to see if it is holding pressure.

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