My first post here - I think, I swear I had an account here years ago, but it couldn't find me. I've read the forum quite a bit, but never had a reason to post. Please bear with me, I know just enough to make things worse, although I do have a knack for diagnosing problems in general (not necessarily for cars). Anyway here is the full story of my current problem:

My car currently has about 250,000 miles. A couple of years ago, I noticed my temp gauge would start to creep up if I was idling a lot. I noticed the coolant reservoir was empty, so I filled it up and it would be fine for a few weeks and would happen again. So I figured I had a small leak in the coolant system. I bought some of that silver glittery stuff and put it in. Problem was solved for quite a while.

A few months ago, I noticed it happening again, so I put more of that stuff in. This time it didn't work and it clogged up the radiator.
So I took it in to have it flushed, that seemed to work, only now it would sometimes lose quite a bit of coolant and the temp gauge would start creeping up again. At one point, I must have been completely out of coolant because I had to essentially shut the engine off and coast in neutral to get to my friends house so we could take a look and see what's going on. We replaced a radiator fan relay and a coolant thermocouple (I think I got that right), that didn't do much, so We ended up having it towed to repair shop. The repair shop put some coolant in and let it idle for a couple of hours and the temp remained fine.

So I drove it home and it began heating up again, so I took it back and we heard and saw some steam coming out of the radator. So they replaced the radiator and thermostat and it's been okay since then, however I still had to put some coolant in from time to time.

Recently (like the past couple of weeks), I noticed sometimes when I start the car, it would be jerky as though it's misfiring, a couple of times the check engine light would flash a couple of times, but then things would smooth out and it would drive fine. So I did one of the few things I can do in a car which is change the cap and rotor. As soon as I did that, the car started up instantly just fine. I figured that was the cause of the jerkyness.

Also, I forgot to mention the check engine light goes on from time to time at any point while I'm driving, and each time the codes come up for random misfires. I don't feel any jerkiness while driving, so my thoughts are this could be a sensor issue or something. I've changed the plugs and wires fairly recently as well and check to make sure the connections are solid.

Anyway, randomly when I start the car, it's jerky and eventually smooths out. I also still have to add some coolant from time to time. So based on this, my thoughts are that I have a head gasket leak. Perhaps the time when I was driving and had to shut of the engine to keep it from going in the read, I did some damage? Does this make sense? Could it be something else? Need any more info?
I don't notice any change in my gas mileage or power - I'm still geting about 32/gal in the winter and 36 in the summer.
Also, is it safe to be driving? If it is the head gasket, is it worth repairing for a car with 250,000 miles that's 13 years old? What should that cost?

Thanks and sorry about the long first post.

-d

 

As a follow up, I took it in to a mechanic. They said that a tempature sensor wasn't working and the radiator fan would then not kick on causing the radiator itself to get hot and the coolant to evaporate. (Does this even make sense?)

Anyway, they replaced the sensor and flushed the radiator, and the car has been fine so far. I guess you can't argue with results. Also it was a lot cheaper than a head gasket job.

-d