So, heres the sitch. i popped two frost plugs, put oem plugs back in, and the coolant system pressurizes until it geysers out of the rad. The shop i use, the dsm guy is sure its a headgasket. One of the mechanics figured a cracked block, something internal, which seems unlikely from the amount and way i drive, temperatures, and how routinely serviced it is. Another shop thinks it would sooner be other things, thermostat/rad cap (seems unlikely a rad cap could hold the pressure to blow two plugs simultaneously) air lock..? Looking for any similar experience or knowledge before i end up spending a lot of unneeded money. Thanks, appreciate any help.

 

You popped two freeze plugs in the first place because you were pressurizing the cooling system. Putting new freeze plugs in hasn't fixed the problem that caused them to come out. The mechanic who told you its a headgasket/sealing issue is correct. Sorry to say, but that cylinder head needs to come off. The only other possibility is that the head is slightly lifting under boost due to the head-bolt (or if you have studs) losing torque. If this is the case, you may (very slight possibillty, but unlikely) have gotten lucky and it hasn't torched the gasket. Just so you know, often if you torch the headgastet, it will also cause some damage to the cylinder head surface area. In essence, the head lifts allowing hot exhaust to enter the coolant passages. This super heats the coolant/water mix and turns it into a blow torch which will take out that section of a soft aluminum head. It doesn't always happen, but it can. Just letting you know that if this happens, the head will need to be welded up and then decked by a machine shop before it goes back on the engine.

 

As the guy above me stated you only popped freeze plugs due to some other issue which is causing them to blow out. In my case I popped a freeze plug in my water pump and I ended up also having a blown headgasket.

If I were in your shoes I'd pull the head get it inspected by a machine shop and replace the gasket. As to the cracked block that doesn't sound very likely IMO. If you wanna experiment with a new radiator cap or thermostat then go for it but realistically I don't foresee it being either of those...

 

What way2qik said was exactly what happened to me right on turn 13 at T-hill. He is absolutely correct, it ate material from my combustion chambers and pretty much had to toss it. a couple thousand dollars later mine is running again.

 

I would have to agree with everyone else. The freeze plugs pop for 2 reasons: freezing temperatures, or the system is overly pressurized. The only way it gets over pressurized is if the head gasket is leaking compression into the cooling system.

 

okay, months later and my car is back in the shop.

I have a few options for you to look at.

Option 1 is to remove the head in car, hoping that there will be an obvious defect with the gasket or head bolts. Should a defect be found we would reassemble with a new gasket kit and head studs after having the surfaces checked at K&S machine. This will cost roughly $1650 labour plus $350 at the machine shop, $445 for a gasket kit & ARP studs plus $122 for engine fluids.

While this is the most cost effective option, we want you to be aware that there is a good chance that we may find nothing wrong with the head or gasket visually and after re assembling you could still have the same issue should the block be cracked. If this was the case you would still have to re & re the engine.

Option 2, involves a full re and re of the engine, you would be looking at $2160 plus the cost of fluids for engine and tranny $226 and a gasket kit $260. You would also need to provide a good used engine at unknown cost or send your existing motor to the machine shop. There would be additional time to transfer the cams if you wanted to keep them in the car with a new to you, used motor.

To check your existing motor properly, you would need to remove your engine to have the block checked. This will require complete disassembly of the engine and extensive additional machine shop costs for what would essentially be a rebuild regardless of whether problems were found. Should there be a crack in the block you would need to find a new one. Honestly I would estimate that the cost for the machine shop to check out and reassemble your engine if its good would be more then finding a used motor.

Now would be the perfect time to start building the engine with performance parts, but I remember you mentioning that funds were limited at this time so I haven’t included these kinds of options.

 

Why not just take the head off, use a straight edge and a feeler gauge, and find out for yourself if the head and block surface is straight, this will answer alot of your questions as to whats going on. Once the head is out you can also look at how the head gasket has been wearing, sometimes you will see obvious signs on the headgasket that it has been failing. Thats my opinion, if you cant do this yourself then tell the shop this is what you want done. Dont let them sell you into tearing apart the bottom end as well for no good reason. I guess its possible you may have a crack in the block, but I seriously doubt it. My guess is you just need a new headgasket and maybe a resurfacing of the head.

 

I just did my own headgasket. It's definitely easier than taking the whole engine out but it is no quick job.

I started working on it this past Saturday, probably put about 1.5h on Saturday, 3 hours on Sunday, 2 on Monday, 5 Tues and about 1.5h to wrap it up yesterday.

My symptoms were exactly as yours, I felt the top radiator hose and noticed there was no coolant in there, opened the radiator cap and pressurized air escaped on cold car, it was missing about 0.75qt of coolant.

I put a yellow funnel on, which I usually use to burp it. It was idling for maybe 40min and still bubbling about the same amount when thermostat opened, so I started doing the obvious.

1) Pressure test the cooling system (it was holding even up to 20psi)
2) Compression: 140, 136, 140, 140
3) Leakdown @ 96psi: 14%, 19%, 14%, 14% (I tried to spot bubbles)
4) Liquid Headgasket tester, let the cooling system pressurize, sniff in some of the fumes and see the fluid turn yellow.

I used feeler gauge to see that block and head were straight, cleaned them really nice, put the new headgasket on and sealed the deal.

If you have some free time and tools, I would do it myself, it ain't that bad and you get to learn a thing or two

 

Tommim is rt-- you need a new headgasket. You ALSO need to have the head surfaced-- Dropping a new gasket on the block will only fail again if the head isn't surfaced to be absolutely sure its flat.