2002 Chevy Blazer

First of all, I wanted to say thanks to everyone who walked me through replacing my sparkplugs and distributor. Car ran like a champ for the past 6 months. Now i have another issue. My car started overheating. On Tuesday I noticed that my temp gauge spiked above 210 degrees. It's the first time since I've had this vehicle that I can remember the temperature getting that high. I pulled over, checked my antifreeze and the reservoir was bone dry. I added some 50/50 coolant and drove home.

Fast forward to yesterday and on the way home I notice that my engine temp was about halfway between 210 and 260. Pulled over, checked reservoir and almost all the coolant I put in was gone. I'm very much not a car guy, I am very much a cheap guy, but I assume since there is a cool and hot fill line that because the engine was hot some was somewhere else in my car (radiator?). by the time I got home the gauge was pretty much at 260 and the check gauges light was on.

This morning I attempted to get it to a friends house where I have the space and tools to work on it. Before turning it on I made sure the coolant level was good and I cranked the heat up to max to cool the engine while I drove. I made it maybe 3 miles before the temp was at 260 and the check gauges light came on. I parked, popped the hood. Coolant level never changed. A little bit of steam was coming from the radiator. And the heat never kicked in, as I was blowing cold air the whole 10 minutes I was running.

Wondering if someone could give some triage instructions. I'm not very car smart but I can follow directions and order parts from Rockauto like a champ.

 

First, do not attempt to run the engine or drive in such conditions
If You see the steam in front of the radiator, then probably it's leaking. You may confirm that by doing a compression test.
The radiator is a very crucial part:

• it cools down the coolant,
• heats up the transmission oil (connectors on the passenger side) and
• heats up the engine oil (connectors on the driver's side)

Needless to say, if there is an internal leak, the coolant may get into the transmission or engine oil, destroying oil film, and resulting in a severe (deadly) damage to Your engine or a transmission.

Pull out the bayonets of these and look what You'll find. Check, if the fluid level has increased or changed consistency. Check what You find under the radiator's cap.
Make a compression test of the cooling installation. From what You say, You seem to have a radiator leaking. Cross Your fingers it leaks the coolant out and do not mix it with oil. Make the compression test and post the results.

 

The coolant disappearing is a sign of a leak. Have you noticed any puddles under the truck? White smoke out the exhaust? Check your oil, brown/black is normal, if it looks like a chocolate milkshake, that's not good.

Also, I understand you need to get the vehicle home, etc. But driving at 260° can do some serious damage to the engine. Potentially turning a simple cooling system fix into an engine rebuild/replacement.

 

I think asking how to find the problem. A place like autozone has a lend a tool program, free usually with deposit. Mine here locally lends a radiator pressure testing tool. You connect that to cold engine in place of radiator cap, pressurize with some compressed air (adjust tool to 16psi) making sure system has good amount of coolant already and look and listen for leaks. A internal leak can be indicated also when pulling oil check stick, looking for milky coating on that stick (oil and water dont mix so it will show) but I really hope that not the case because this a real bad bad thing to have happen.

Obviously if you find no leak then the cap itself must be source. If leak found go from there on repair. I’d recommend flushing the system out when you do repair, several posts on forum for doing that. Refill and “burp” it and should be ok. As others have advised, very bad to run it over heated for major damage can occur to several components. Considering the age of our blazers and not knowing how yours has been maintained would not be surprised if you find radiator itself is cause.

 

Your heater is not working because the system has air in it. Park it with the front end higher. Take off the radiator cap and fill while running the engine until the thermostat opens up and you are spilling over a little. Then put the cap on before it’s too hot. Don’t run it hot like that but I have driven around with a leak and a few gallons of water in the back to keep topping it off until I can fix it. Lyle makes a neat funnel tool for this that works well. If my fill instructions don’t get the temps down then I agree don’t drive it because you may have other problems like water pump, thermostat, compression leak etc

George

 

Thank you all for the suggestions. So I had some personal crap that happened that kept me from working on my car until now. Coupled with the fact that I leave for work in the early AM and get home near dusk I haven't had a good chance to do any troubleshooting. I did have to move it last night because of street cleaning and didn't want to get a ticket. I bough a bottle of coolant, put it in, and just drove around the bloc to park on the opposite side of the street. I got out, and coolant was dripping pretty steadily onto the ground. Same color as the coolant I put in. I checked the oil and it was very blackish brown. So I think it's either a hose or the radiator itself. i can't see anything leaking from the top or the bottom, so I'll have to lift it up tomorrow and test. I'm renting a compression kit from Autozone on the way home so hopefully that will tell me where this leak is.

 

Another update. So someone grabbed my socket set so i couldn't remove the bottom cover on my truck. I hooked the ac compression tester up and my radiator cap read 15 psi, but no matter how much i pump it wouldn't go over 5psi. I don't think the seal from the test plug is the issue, so I'll have to wait until Tuesday to get underneath my truck. bought a thermostat, water pump and radiator hose just in case.

 

OK, I feel like the dumbest dummy who ever dumbed dumb.
So I rented the compression tested but no matter how much i pumped it wouldn't go higher than 5PSI, then would slowly go back to 0. Didn't see any radiator fluid leaking but could tell it was leaking bad somewhere. Used sudsy water to see if bubbles formed, nada. i figured it had to be my thermostat or water pump as there was some sludge on the water pump. Order them from Rock Auto. Went to remove my radiator fan and almost stripped the bolt holding it on. Decided to just have a mechanic fix it so my cousin towed my car to his buddies shop. I gave the guy the keys and hopped on the bus home. 15 minutes later I get a call saying to get my butt back there. I go in, and the mechanic grabs a flashlight, pops my hood, asks 'you said you checked the radiator hose, right?' I nod, and he reached down to the hose and with one finger, DISLODGES it. my clamp wasn't on tight at all. I went thru 2 weeks and 30 hundred dollars when all i needed was a phillips head screwdriver and 2 minutes....

 

Oh, man. You know you're never gonna hear the end of this one, right? Lol

Bet you're glad it's fixed, though!

 

I know.

Common Sense=1
Me=0