Bulging Rad Hose, Blown Head Gasket?

[SirFoxx]

Hello once again --

I was perusing around the internet the other day and found out that one of my local auto stores had a radiator for my tercel in stock. My old radiator was a plastic top tank, with a big crack going from the filler neck to the bottom of the tank. I picked up the new radiator, and installed it. The new one is a metal top tank, which I think is awesome. However, here is where the problems come into play.

As of recently, I noticed that my car would blow some thick, blueish white smoke out the exhaust pipe if you turn it off, and back on again after letting it sit for ~5 - 20 minutes. I thought maybe it was bad valve seals, so I replaced those yesterday (I did have 2 sets of bad valve seals by looking at the spark plugs). Got it back together, took it to the gas station, and it did the same smoke thing. Crud, I thought, maybe the engine is pretty worn out...

Here comes today, and got the radiator in, drove it for ~2 miles, and while sitting at a stop light, it started idling a bit oddly. Green light comes, and I step on the gas, and I laid out the biggest white smoke screen I have seen come from a car. I immediately pull into a parking lot, open the hood, and the upper radiator hose had a huge bulge in it.

I go get another radiator cap, thinking mine was bad, and maybe the head gasket was still good....Nope. I started the car and put my ear to the radiator neck, and could hear some gurgling, along with the pulsation of the engine running. So my questions are --

Radiator hose -- I know they fail like this when they get old. Could have mine failed due to age + too much pressure?
Old radiator -- What could cause too much pressure in the cooling system to cause the radiator to crack?
Head Gasket -- When I got the new head gasket installed, I was not using coolant, nor was it gurgling in the radiator. What could have cause the head gasket to fail prematurely? What could I do to make sure this doesnt happen again?

[xirdneh]

I have had some bad luck with headgaskets
May have been because I did not chase the threads in the block. Throws torque off if you do not do it. Makes a big difference on feel of torqueing. All bolts tightened on three passes and each feel the same all the way through.

[teranfirbt]

Holy crap! Definitely need to replace that hose (Gates or Goodyear are the only non-OEM brands I trust for hoses). To see if you're burning coolant check your plugs, if any are sparkling clean that's a sign you've got a blown head gasket. To be double sure, bring each cylinder to top dead center and look at the top through the plug hole, the piston top should be black. If you see shiny aluminum then you know you're burning coolant.
Head gaskets are pretty easy in these cars, Petros made a guide that covers a few things that will help prevent future issues. Things to pay attention to are the flatness of the block and head surfaces those must be flat flat flat. The extra holes in the head gasket are also important. A good tool for making those cleanly is a step drill since they're made for drilling thin sheet metal.

If you don't have clean plugs or piston tops, the next step is to rent a leak down tester from autozone/similar and see where things are. This will tell you if you have leaking valves or rings. Do a compression test as well, all cylinders should be above 140 and fairly even, 15 psi max spread.

[Petros]

if you had a crack in the old radiator, I do not see how it is possible not to loose coolant, and risk overheating it. Which of course would compromise the head gasket, even if it never got into the red zone on the gauge.

A bad head gasket could over pressure the cooling system, but the relief valve in the radiator cap prevents too much pressure build up. If the head gasket is leaking bad enough to cause excess pressure in the cooling system you will get coolant being blown back into the coolant over flow canister, overflowing and spilling out. And likely you will feel like it is running on three cylinders, which is pretty obvious. The only way significant over pressure would occur is if the head gasket was bad, and the pressure relief valve on the radiator cap was bad and stuck shut. That is rare but I have seen it happen.

The upper rad hose is bad, whatever the cause, replace it. Make sure the rest of your cooling system is all operating properly, monitor temperature and coolant consumption carefully, and get some other confirmation that your head gasket is bad, like those noted above.

Make sure you diagnose the problem BEFORE you try and fix it. That means do not replace the head gasket unless you know it is bad, and also, try and find out why it failed, or the next one will fail too. Use my head gasket replacement procedure over in the repair guilds section.

[donnyre]

Bulging radiator hose can be a sign of compression leak which caused by a cracked head or blown gasket.