Hello all I�m new to this forum. I signed up hoping I can get some help on my problem. I have a 04 Silverado with a 5.3. First Chevy truck I have ever owned. At 200k the truck slowly started losing water and I discovered it was a cracked head. Cracked right by the cylinder head bolt. It had the 862 heads on it so that�s what I replaced them with. (I hear they are the best option)? I used all good parts. Factory gaskets and I used ARP head bolts because factory bolts were ridiculously expensive ($350). Well 6,000 miles later. One of the new heads cracks. AGAIN. The head is under warranty. But this is bs. I don�t want to constantly be wondering when it�s going to happen again. Does anyone here know of a better set up or a solution? Without spending crazy money? I�m really not impressed. I am very meticulous when it comes to working on my vehicles. I know I did it right. Please give me some imput!

 

Did you research his problem at all? It's well known to plague the Castech castings, which are identifiable by a battery logo cast in the rocker arm area.

 

Yes I researched it a lot when I replaced the heads the first time. The original heads were not castech. And the rebuilt heads I installed were also not castech. Do I just have really shitty luck? Should I have used stretch bolts instead of ARP? Are these heads just a shitty design?

 

What condition is the truck's cooling system in? Did the truck ever overheat?

Often vehicles have other issues like head gaskets etc due to a compromised cooling system.
Dex-cool coolant if it's not changed eventually starts to clump and can impede flow in the radiator.

 

Make sure your deck is flat if you pull the head off again. And I agree with the cooling system. Maybe flush it. I'd replace the temp sender to ensure its reading properly. Cheap insurance.

 

Did the head crack in the same area? Pictures of both heads would help.

 

I bought the truck with 194k on it. And it had the green coolant in it that looked old. (More yellowish). So I flushed the system really well and put dexcool back in it. I have a feeling the original head had a crack already, and when I flushed the system the crack started leaking. The truck has never gotten hot since I have owned it. A little warm maybe but not hot. And yes same head cracked this time by the bolts. First time one cracked by only one bolt, and this time it�s by 2 of the 3 center bolts for sure and the 3rd looks like it�s starting. I�ll get some pictures this morning. Last night I sprayed the areas by the bolts with brake clean and then put 15psi to the coolant system and watched the cracks show coolant seep.

 

Also should I have used stretch bolts instead of ARP? And if the block is warped what do I do? Junk it and get a whole new junkyard engine?

 

The ARP bolts will be fine. The stock TTY bolts are just a different method of preloading the bolts. Just make sure the holes are super clean and use the ARP lube for an accurate preload based on torque.

 

I'm betting if you have good heads, its cracking because of the block isn't flat.

 

Yeah I'd bet the deck is way out of whack.

 

I tried posting pictures but they aren�t up yet for some reason. If the block is out then I guess start over with a short block or whole engine. If the block isn�t bad then I just have real shitty luck? What straight edge can I use to check it? Anything that�s really straight? Ha. I don�t have 24� parallels laying around.

 

Most people have a level handy... they work... if you don't want to junk the engine, a machine shop can deck the block for you... probably needs to be bare tho... it's usually done during a rebuild.

 

Hi Silver, YES it is better to fit a fastener that will stretch the correct amount, the amount the AL head was designed to grow keeping the clamping pressure constant.
My method when ARP is specified, by the customer, is to UNDER CUT the bolt/stud to match the original bolt stretch.

I was the one who had the task to install the Deck Plate to the head and tighten it correctly when I worked at HMS. (1970)
I then carried the head to the man, Wally Cartwright, who cut the seats.
WE had learned much about a cylinder head being damaged by TOO much clamping force.
WE found the valve seat would go "out of round" when deck plated vs bench ground.
WE fit "pressure paper" between the head/plate and the head/crankcase.
The "paper" changed color with a report of pressure force then known.

I too agree their may be other problems, I would go to Harbor Freight and BUY a straight edge for crankcase measurement.

Lance

 

Ok everyone I replaced the head and have put 1000 miles on it. Started using a little water right off the bat. Real slow. I thought maybe it was an air bubble working it�s way out. Nope! 3rd head is cracked. And I checked the block. It is perfectly flat. I used a starret 24� straight edge and feeler guages. I don�t know what is going on. I�m almost starting to wonder if it�s the head rebuilder doing a shitty job or the heads are already cracked when I get them? He runs a reputable shop tho rebuilding thousands of heads. I have a hard time thinking his shop is the problem. I don�t get it.

 

Get some good used heads on Craigslist or something don't get some already destroyed and "rebuilt" heads from some hack.

 

I'm with Jimbo on this one.

 

Could it be the steam vent?

 

Yeah I don�t know. But this is ridiculous. I�m really not impressed. Im going to look for a head somewhere else. I just don�t know how it could be this shitty. Hopefully the head rebuilder refunds me. I wish someone casted a better head for these engines. (That don�t cost a fortune) 3 heads in a row make me feel like this just going to happen again no matter what. If it does I�m getting rid of the truck

 

You don't need better cast heads, you just need some that aren't already fucked.