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How Common are LS1 head gasket Failure?

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Old Jun 4, 2013 | 01:00 AM
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Question How Common are LS1 head gasket Failure?

Hey guys,

I'm about to start to tackle a project for my good friend Rick. He has a second Trans Am that has been off the road for 2 years. It’s a shame.

We have become good friends a little over a month ago when I rebuilt the top end of his 98 LS1, Failed spring, mismatched springs on each head on that project. Now that his favorite Trans-Am is back up and running we are tackling his Project car.

Here is the short and simple of it. Head gasket failures on the LS series are almost unheard of, which makes me wonder if I need to look out for anything else before I rip into this project in the next couple of days.

This engine runs completely normal, except for the disappearing coolant.
No white smoke out the tail pipes, no misfires, and yes it runs at a nice cool 170ish in temp.

I know it’s either a head gasket failure or god forbid a cracked head. Let’s just hope it’s not the block.

I am a Tech by trade. Exhaust gasses are getting into the cooling system over pressurizing it and causing it to slowly boil off.

Old school dyno machine with the gas analyzer comfirmed that. It putting off 54 ppm of HHC at idle, but when you rev it up to 2,000 rpms it just right up to 260 ppm, at the pressure cap.

So bottom line because I personally never seen a head gasket fail on these motors is there something I’m not aware of? Like a casing run of blocks or heads that are prone to cracking or anything like that. They are just not that common.

This car is stock! With about 140,000 miles on it and it’s never been touched under the hood except for air, oil and filter changes.

I’m just curious if anyone has had this happen on a stock engine with no mods, and like I said has never been apart.

Of course as the last thread Rick and I did we will post project pics so people can look at how things come part, and to keep all updated on the project. You can have never have too many tear down motor threads.
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Old Jun 4, 2013 | 02:49 AM
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To answer your question is there any major things to look out for, not really. Pull the heads, check for deck warpage on the block and the head surface. Inspect for cracks although its very uncommon at least from all the LS motors I have seen.
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Old Jun 4, 2013 | 02:53 AM
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When Randy Savage gives a solution you listen lol.
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Old Jun 4, 2013 | 02:59 AM
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Originally Posted by 2000PewterT/A
To answer your question is there any major things to look out for, not really. Pull the heads, check for deck warpage on the block and the head surface. Inspect for cracks although its very uncommon at least from all the LS motors I have seen.
Oh Im measureing for bannana's heads for sure. I have a machined straight edge. This isn't my first time. Thing for the suggestions. I just wanted to make sure there wasn't a casting issure in those years

Bolts and gaskets are all realy on order. Ill rip though this project in about 8 hours with the engine in the car.. maybe 6, it depends on how hot it is.

Steve
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Old Jun 4, 2013 | 09:13 AM
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I just went thru this issue in the last few months. No smoke and it ran great... just ate coolant. Ended up finding a HG leak on #7 (80,000 miles). I ended up welding the tabs on my 98 heads and installing MLS .045 gaskets for better quench. The original graphite gaskets were in terrible shape.
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Old Jun 4, 2013 | 10:23 AM
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I am not sure about the LS1 heads but the truck heads had some bad castings that leaked anti freeze.
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Old Jun 8, 2013 | 09:15 PM
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Okay sounds good guys. The whole thing caught me off guard becuase as experenced as Im am in LS engines I have never seen this. Like I said everything thing is getting measured. My main issue was a crack in a head or something like that that I wasn't aware about. They heads are coming off tomorrow so Ill know the cylinder that was drinking the Koolade
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Old Jun 9, 2013 | 11:51 AM
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Originally Posted by gagliano7
I am not sure about the LS1 heads but the truck heads had some bad castings that leaked anti freeze.
IIRC this happened in the early iron head 6.0s I never heard to much about any of the aluminum heads.
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