Blown head gasket

I have a 2001 mitsubishi eclipse rs. I have a good mechanic which i have been using for the past several years. He has always been fair and honest with me. He has recently changed my radiator about 1 1/2 month ago since it was an old radiator overheated and cracked. After the change of the radiator about 2 weeks ago the radiator overheated which he told me to put water in it and drive it to the shop. It turned out to be a loose hose. 2 days ago i was driving on the highway and it started steaming i pulled over checked under the hood it smelled like smoke. I called the mechanic and told him what had happened he suggested to me to put water and drive it to him again like the last time. Which is about 6 miles both times. I drove about 4 miles and it started splashing water from under the hood so i stopped and looked under the hood the water was bubbling in the water/compensation tank. I told the mechanic this and he told me it sounds like you blew the head gasket. So i towed the vehicle to him and he confirmed it. My question is the following. Why did the head gasket blow? Did it have to do with the radiator overheating again and if so isn’t my mechanic responsible for not doing the job right the first time. Also about how much does it cost in parts and labor to change or fix a head gasket?

I present the idea that the headgasket was blown at the time the radiator was replaced and the heat allowed to enter the coolant by this blown headgasket was the cause of the radiators demise, the mechanic missed the blown headgasket when he replaced the radiator.

The head gasket blowing may well have caused the other problems. It is also possible the radiator (or other) leak caused over heating that that could have caused the head gasket problem. No way now to determine if it was the chicken or the egg.

Sorry I don’t have an idea on the cost.

I don’t see that this was anything other than bad luck. A vigilant driver may have spotted a problem before it did additional damage, or maybe not.

The head gasket can fail due to overheating and you can overheat due to a head gasket.

Yea, unfortunately there is no way to sort it out. As noted, your initial radiator problem might have had a bad head gasket as the underlying cause; OR the initial radiator failure & overheating may have warped the head/blown the gasket; OR the later events could have killed the head; OR there is still the possibility of a coincidence.

It’s possible the head gasket could have been weakened from the first overheating episode. Any time an engine overheats you MUST pull over then and there and shut it off. If you continue to operate the car you may be turning a minor problem into a major one.
The mechanic should have at least made you aware of this the first time.

The thermostat could also be responsible for this and that’s a quick, cheap fix.

As to any head gasket failure (assuming the HG is even bad) that’s a touchy issue. Chronic overheating and continuing to drive the car only causes more problems involving piston rings, valve seals, etc. In other words, replace a HG and you may have a car that burns oil quickly.

My opinion is that a compression test should be run on all cylinders and if a piston ring problem exists (and if the timing belt has never been changed) it may be time to dump the car or replace/rebuild the engine.

If this is the headgasket is this typically what happens when a head gasket goes bad, or does it depend on how bad the headgasket is damaged? Reason I ask, is i believe my old beater has a bad headgasket, but nothing like has happened on mine as of yet and I have been driving it now for over a year and put on almost 8,000 miles.

Years ago, I replaced the radiator cap on my 1954 Buick. A couple weeks later, the radiator started leaking so I had the radiator repaired (this was in the days when radiators could be repaired). After the radiator was repaired, the water pump started leaking. All were related–when the radiator cap was replaced, the system developed the presssure that it should. This pressure caused the radiator to leak, partially relieving the pressure. When the radiator was repaired, the next weak spot was the seal on the water pump. After all these things were fixed, the cooling system required no more repairs as long as I owned the car.

Every situation is different; even on the same make/model of car, and engine. Some gaskets give up pretty quickly and some may never give up. Others may surrender 6 months or 3 years later; it’s anybody’s guess when overheating is involved. Much depends on not just the severity of the overheating but how long it was overheating.
With an aluminum head or all aluminum engine it often doesn’t take much to pop a head gasket.

My suggestion about a compression test is to make sure you don’t spend $$$$ on this job and then discover the engine has far more serious problems. A blown head gasket will generally affect only 1 or 2 cylinders. This is why you test all cylinders because if the unaffected cylinders show a ring problem (even on 1 cylinder) there is no sense in even considering a head gasket job.