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cracked block or cracked heads

3K views 12 replies 4 participants last post by  4x4Chevy 
#1 ·
I have recently done a 350/350 swap into my regal and when I first went to fire it up it ran but water/coolant came pouring outta my headers. Initially I thought head gaskets bc it had been sitting about a year and a half. When I pulled the heads I had a cracked valve so I took them in for a valve job. I got everything put back together and check torque on my heads well. I first fired it up and all was good til I started adding more coolant then all of a sudden it was another waterfall out of both headers. I suspect a cracked block but I am not sure and really need some help. Please and thank you
 
#3 ·
Yes there is water in the oil. And no I did not have then checked bc it is the motor out of my truck and it ran fine and only had a little oil leak so I figured it was good. Head gaskets sounded like the problem at first bc its got almost 200k and never had a major problem but am wrong. Its weird to me bc blows water outta both headers. And its alot!
 
#4 ·
As much as I hate to say it, it was not a good idea to take in heads with that many miles and not have them magnafluxed to check for cracks. Being it was already pouring water out the first time should have been a sign there was more wrong that just a bad valve as valves wont cause water to come out of the exhaust. You'll have to remove the heads and have them magnafluxed, if they check okay and you wish to reuse them then they will need to be surfaced to get the decks level. You will also have to check the blocks decks for flatness, if you find anything over .002 on the block deck it will need resurfaced as well which means it will have to come apart so you may as well do a rebuild.
 
#5 ·
The engine may have been fine when in the truck, but sitting for 1.5 yrs. anything can happen. If it gets cold enough where you live the block could have cracked sometime during that period.
Not way to say whether it's the block or heads, so you'll need to decide if you want to tear it apart again, or toss it and start over.
 
#6 ·
Ya I only took the heads in for the valves bc one was cracked and I know they wouldn't cause the water issue. I shoulda just had them magnaflux em yer right. Im probably just gonna go ahead and rebuild it. But is your thought maybe a cracked block possible?
 
#7 ·
I would guess that once the heads are checked you'll be able to make a better guess. If they are it doesn't mean the block isn't also, but if they aren't then it's the block for sure.
I would get to it fairly soon as water sitting in the ore will quickly rust and pit the bare bores, then you'll be boring it for sure.
 
#12 ·
4x4Chevy said:
I just called the machinist I had do my valve job and he said that he did magnaflux my heads and they checked out good... I dont know if that strengthens the thought of a cracked block? Anymore ideas??
Ayuh,... Drain the block, 'n cooling system,...
Pressurize it with 'bout 15psi, 'n Listen.....

You'll hear the air escaping, follow the sound.... :welcome:
 
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