I spent 4 hours under the hood of my car today, despite being probably the last person anyone expects to find elbow deep in machine entrails.
Last Saturday driving around my engine started to overheat. I pulled into a gas station, bought a bottle of coolant, walked around for a bit to let it cool off, and tried to open the radiator cap. I couldn't get it off, and I'd only ever been under the hood of one other car, so I thought maybe the tube leading to the radiator cap was where I put the fluid. So I filled up the overflow tank (olol) and managed to get it home, redlining the heat gauge for a solid mile.
Skip to last Sunday - I figured out how to get the radiator cap off, and the radiator was wet, but not filled with fluid. I took it to Firestone, just a few blocks away, since it needed an oil change anyway. I asked them to do a pressure test on the radiator while they had it, and they found a leak near where the aluminum was welded. They wanted some ridiculous amount of money for it - I think the initial estimate was 500+ (for all the hoses/fittings, and shit like tag bulbs, etc). I couldn't really afford it, and they brought the price down to 450ish, but I knew the radiator itself was only about 100. The tech was really nice, and he showed me what I'd need to do to replace it myself, and even recommended an online retailer. I'd already watched a really good youtube video on replacing a radiator, so he was able to point out things on my vehicle that I knew about.
The radiator showed up here on Friday ($100 online with shipping), and Saturday I figured I'd drive it around before I did any serious work and see if the problem was just a product of the insane heat last weekend. Firestone had topped off the radiator, and when I checked, there was visible fluid. I found myself wondering if the problem might be the thermostat instead. It drove fine for a few minutes, got up to optimal heat, and stayed there for about 3 minutes. Then it overheated, and by the time I got it home there was so much heat that I didn't want to work on it.
Today I pulled out the old radiator (after much swearing, three trips to Auto Zone for tools I didn't have, and a gnarly hand wound across the knuckles) and put the new one in. I'm certain I reconnected everything properly. I filled the radiator with fluid, closed the lid, and took it for a test drive. I was fine for about 5 minutes, then I saw that slight uptick from optimum temp that signaled it was going to get hot, so I turned around and headed home. It got to redline on the way, so I pulled over and popped the hood. The coolant in the overflow tank was boiling, and there was a drip from the upper hose where it connects to the thermostat housing. But that hose was clamped tight, the crimp-style clamp was exactly where it was before I took it off, I could tell because of the indentation. In fact, now that I think of it, I didn't even remove the upper hose at that connection point. I did loosen the clamp and try, but it didn't budge, so I just moved the clamp back.
When Firestone tested it, they said it wasn't a head gasket. It's not the radiator or the radiator cap, and it's not the radiator fans. So that just leaves the thermostat, right? Is there any part of the cooling system that I'm not considering?
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That's true, it could very well be your water pump (though, if it was defective you would definitely be hearing it chugging along).
Having disassembled the radiator today, I'll take another look at it tomorrow and see how comfortable I am pulling it off. It seemed to be, uhh, wiggle-able, so maybe it just pulls off if everything is unplugged from it. But I'm also not sure if I can get my socket wrench into that small space to take off the thermostat housing.
If it's boiling it's because the system isn't able to properly pressurize. This could be because of a leaky hose, a faulty water pump or a leak somewhere else in the system.
When you first start the car up does it smoke at all? Does the exhaust have a sickly sweet smell?
What kind of car are we talking about here?
Replace them all, definitely. If they've never been replaced in 114k miles, it certainly can't hurt.
Most Definitely. that many heat/cool cycles will kill a lot of rubber hoses in the engine bay.
The procedure for this is:
1. with the car cold, take off the rad cap and put a funnel into the hole, it is better if you have a funnel that fits tight into the hole, but not a requirement.
2. fill up the rad as much as possible
3. Start the car (this wont hurt anything, you might get a bit of collant spill, but its not a big deal, you can clean up at the end)
4. while watching the temperature from time to time, continue to fill the radiator as the level goes down (air bubbles will come out of the hole and lower the fluid level), let the engine idle up to normal temperature, and for around 5-10 more minutes (shut it off if it overheats).
5. shut off the car and close the radiator
It does sound like your car is just boiling the coolant now, and you may have a leak in the upper hose, they get old fast and dont like to be jiggled around or have their clamps loosened, they tend to crack, so you may have to replace the hose. That should be done before the above procedure.
The problem with driving it around while overheating is while you may not have had a headgasket issue when the tech looked at it, you may have created one while driving it around and overheating it, this will also cause coolant to boil.
Tried to measure it visually since there were no marks on it, cut it down with a bread knife because it was all I had. Went to put it on, and it only covered the fitting points about halfway.
So mad at myself right now. I bet I could have even gotten it on there without cutting if I really forced it.
I get to try again tomorrow.
Also, fuck this North Carolina heat. How is it still in the 90's at 9pm? Unless I work on my car at 6am, there's no way to be comfortable.
Couple years back i had a failed one and was overheating with no clue what was going on, and that was the issue.
I think I'm going to give the hose some time to conform. Maybe I'll put the antifreeze in and test it out later tonight.
Considering it's 90 + out, couldn't you just use water instead of antifreeze? I mean... there's no way it's going to freeze so you don't need antifreeze...
Edit: Serpent, Antifreeze and coolant are the same thing. It's a fluid mixture that has a higher boiling point and lower freezing point than water. You can put water in a radiator, but it won't keep the engine as cool. In theory it should still be enough to keep a car from overheating, but antifreeze is basically better in every way but cost and disposability.
Taking it to Carmax tomorrow. Not worth fixing.
Getting a new car.
Some of this is correct, some is not. Coolant is generally the same thing as antifreeze, in that antifreeze is what is added to water to make it coolant. Coolant does indeed have a lower freezing temp than plain water. Coolant does not have a higher boiling point than plain water. The reason the coolant in your cooling system does not boil at temps higher than 100 degrees Celcius is because the cooling system is pressurised. Usually to half a BAR, or about 7psi. Antifreeze does not do a better job of keeping your engine cool than water, antifreeze actually inhibits thermal transfer into the water. But without antifreeze, your cooling system (engine block, radiator, thermostat housing + water pump, heater radiator, and sundry other items) corrodes much faster. The biggest cause of corrosion in a cooling system is galvanic corrosion, where dis-similar metals (cast iron, cast aluminium, brass/copper) literally eat each other, and antifreeze has inhibitors in it to slow this process.
Anyway, I unloaded the car at Carmax last night. I took it in the shorts, but at least now I have something I can use as a down payment on something better. Incidentally, I think the body work devalued the car more than the mechanical problem. Our asshole neighborhood has some punk ass kids, and they've keyed the car on a number of occasions.
Funny story, though - when they asked my why I was selling it, I told them I have a long commute and the car just wasn't comfortable to drive. Which is true. The previous owner had like a massive thyroid problems, so his massive bulk totally smushed the driver's seat into an odd shape. I started saying "the previous owner..." then realized the sales person we were talking to was a pretty large dude, too, and stumbled through the rest of the sentence.
Such utter douche-baggery...