2001 3.4l cracks in head deck

[rooster5333]

Hello, I was wondering if anyone could answer a question for me? I am replacing head gaskets on my 01 Olds 3.4l ohv. I have found cracks in the head deck, near the head bolt boss between 2-4 and 3-5. The cracks run between the coolant passage holes only. They appear to have been there for a long period of time, as the appearance of the cracks show up in the old head gasket. There is no sign of leakage in the area at all, and seem to have not affected anything. My question is, is this a common issue? Can I ignore it? Or, do I have to replace the engine? Thanks for any help you can offer.

[ForcedFirebird]

Would you mind posting a pic? There seems to be one area with an issue and would like to resolve it.


Welcome to the site!

[rooster5333]

I have no way to post a pic for this. Is there any other info I can offer?

[AaronGTR]

Just to clarify, are you talking about cracks in the cylinder head or the engine block?

[rooster5333]

The cracks are in the engine block. On the head deck. Running from one water passage to another. AND are mirrored on both sides of the engine. Only found them while cleaning. They impressed onto the old gaskets, so they have been there a while. And dont seem to be causing a current problem. Just wondered if this has been seen before, and if I can ignore it, or replace the block.

[ForcedFirebird]

OH WOW!

I am sorry, I was looking for more data on the head cracking issue that has been observed.

suddenly more interested...

[rooster5333]

yes,it is a strange problem. but its not the head that is cracked, it is the block where the head sits. i personally have never heard of this before on any motor.

[Superdave]

Well.. that's not a common thing at all.


You have a 50/50 shot, You might get lucky and it never hurts anything but it wouldn't be a bad idea to toss $20/week in a jar just in case.

[rooster5333]

20 bucks a week probably wont get. if it dont work, it wont work real soon. i might need 1500 bucks a week in a jar, so i'll have it next week when i need it.

[bszopi]

$1500?? If all you need is a block, then... http://60degreev6.com/forum/showpost...4&postcount=21

Not sure where you are located, but for $120 plus freight (maybe $150 for just the block), it would be a good deal if you are that concerned about it.

[ssdurango]

Why are you replacing the head gaskets in the first place? Could the reason be related to cracks in the block?

[AaronGTR]

The cracks are in the engine block. On the head deck. Running from one water passage to another. AND are mirrored on both sides of the engine. Only found them while cleaning. They impressed onto the old gaskets, so they have been there a while. And dont seem to be causing a current problem. Just wondered if this has been seen before, and if I can ignore it, or replace the block.

That's what had me confused, the terminology. Most people don't say "the head deck". The head is the head.... the top surface of the block is usually simply referred to as "the deck".

[rooster5333]

That's what had me confused, the terminology. Most people don't say "the head deck". The head is the head.... the top surface of the block is usually simply referred to as "the deck".

Sorry for any confusion. I just wanted to give as much info as possible. I've asked a couple gm techs & machine shop techs and even here, and no one has heard of this before. INCLUDING ME!!! And as far as why I'm doing the gaskets, well lets just say it would make a great episode on "Seconds From Disaster".

And is the direct effect of STUPIDITY IN ACTION!

But, what's done is done. No sense crying... With the repair cost approaching $500, plus other incidentals while it's tore down (it's a 01 silhouette, can U say tight), I'm still not sure I want to put all the time/money into a future grenade!! I have been around these engines alot. I had a 88 S-10 blazer 4X4/2.8l. A 94 Baretta 3100. 01 silhouette 3400 (blown head gasket 12-01-09). I still have a 97 MC 3100 (broke cam 12-29-09 @170k mi-back road/big truck/double yellow line/ enuff said??). Did lim for friend on 96 Lumina, which they immediately wrecked the bottom end on the next week. But this is a new one for me.

[geoffinbc]

Well if your replacing the gasket because it blew then whatever cause that may have caused the cracks. Was it over heated or frozen with no antifreeze in it. Either one could cause cracks.

[rooster5333]

Yes it overheated, but not badly. Enough to mess up the head gasket. But only the front head and on the drive belt end, next to the water pump housing. These mysterious cracks are on both banks. And!!! in the same relative spot. Heat most likely caused these cracks, but they were obviously there for a loooonngg time. And not causing a problem, i.e. no leaks or other issues. The gasket blew away and apart from these cracks. I have discovered that this issue is an unknown problem, and I guess I will just go ahead and reuse the block as is. Once I get it going, I will find out if it will work. I will also report back about my success or more likely my failure with this issue. The heads are in the shop now for a complete rebuild. When they are done, I will reassemble and cross my fingers. I hope you all will cross yours for me also. MANY THANKS FOR ALL OF YOUR RESPONSES!!