[GLH_Shark]

What acutally causesthe head to crack on our cars, is it just a bad cast design or something to do with the coolin systems, is there ways to prevent it or repair one, and does it happen to all t3 heads, i just wanna know and be prepared if or when it happens, thanks

 

[darktone]

the guy that did the warrenty repairs for Chrysler said it was poor design and thin metal in the core plug area. He say's the steel core plugs had nothing to do with it and the aluminum ones are used to weld the holes shut. Others say over torquing the plugs do it too but he say's it's just the poor design.

 

[GLH_Shark]

After you repair the head is it fixed or can it still crack the same way. does it fix the defect?

 

[Turbo3IROC]

That's probably dependant on the quality of the work. If it's done well then I don't see it cracking again.

 

[Chris Faulk]

the guy that did the warrenty repairs for Chrysler said it was poor design and thin metal in the core plug area. He say's the steel core plugs had nothing to do with it and the aluminum ones are used to weld the holes shut. Others say over torquing the plugs do it too but he say's it's just the poor design.

I'm gonna have a hard time believing this...

When you put a hard metal like steel into a soft metal like aluminum they are BOUND to expand and contact at much different rates.

I will certainly agree that thin aluminum will also contribute to this failure.

 

[GLH_Shark]

so they only crack around the plugs, know where else?

 

[91RedSpiritRT]

also seems to have something to do with how the stock plugs were installed. some are flush with the head, some show a couple threads. thats how mine is, 109k and no signs of it leaking a drop of coolant through them!

 

[GLH_Shark]

so they only crack around the plugs, know where else?

 

[Turbo3IROC]

It's near the core plug but not right up to it. I think on mine it was about 1/2" away from it.

 

[GLH_Shark]

i have access to aldata and they gave me a p/n for plugs to replace to help with this problem, should i do it?

 

[darktone]

If the plugs are still available from Chrysler pick them up incase you have to weld your head in the future these aluminum plugs will be needed. But if you have no cracks I would leave well enough alone and just hold onto them incase you have problems.
I asked Brent at Star motors about the theory of the over tightening of the core plugs when I had my head done and he said this is not the cause of the problem- just bad design and thin metal. I had a chance to talk with him yesterday and he estimates he had welded 400 T3 heads just for Chrysler- I'll take his word of what causes the cracks.

 

[xtrempickup]

the aluminum core plugs are available from FWD