Hey guys, MERRRRRRY CHRISTMAS!
My family has their big Christmas party on Christmas Eve at my grandmothers. I was the last person to leave. My girlfriend and I were driving to her apartment (some 20 miles away) just before midnight because I had forgotten my dad's gift in my girlfriend's car. On the way, I noticed my temp gauge would not go down. Some background, for awhile now, I've noticed that usually my temp will actually go above the middle hashmark before going down to the 190 that the car runs on. Anyway, I pulled the car over at a Walgreens which happened to be open until midnight. I pulled off the cap to the overflow to check the level, and it was quite high. I left that cap off, took the oil cap off (to cool the engine), and then opened the radiator cap to the point at which it will let air in and out. As soon as I did that, the fluid started bubble like mad. I don't know if it was air coming through the system or it was just boiling.The heat from each of the three openings against the cold 3 degree air created little pillars of steam. We shopped around Walgreens until they closed, came back to my car, started it up, and the temp was at 210. I drove it until it got too hot for comfort again. By that point, we were about 1 mile from my girlfriend's apartment. I let it cool another 15 minutes, and made it back to her apartment, and drove her car back to my folk's place.

Here's some background on my cooling system:

• the fluid is probably out of ratio as far as anti-freeze to water goes
• The fluid in the reservoir tank was clouded brown, likely from rust
• there is a combination of regular water and distilled in there
• I once did a radiator flush and didn't know I had to bypass the heater core.
• I had the heat on to try and take heat of the engine when I was on the freeway. It was very hot, when all of a sudden the heat totally went away and cold-blown air replaced it.
• I have already done the intake manifold gaskets.
• the little hose that goes from right under the radiator cap to the overflow tank has a drip leak. I think the hose that goes over the hose nipple on the radiator is cracked. Can't see how it would be related, I just need to cut an inch out the bad section, it's at the end, so I can just take it off and reuse what's left.

It was 3 degrees outside last night at the time that this happened. After some internet research on the problem, my guesses are that:

• my radiator fluid is so diluted, that it isn't adequately protecting against low (freezing) and high (boiling) points in temperature
• the heater core is clogged, stopping or restricting coolant flow
• I've blown some gasket
• bad water pump
• bad thermostat

My guess is that it's a combination of the first two things. I can't unclog the heater core where it is now, as it's in the parking lot of girlfriend's apartment complex. My plan of attack, unless you have a better idea, is to go there tomorrow, drain the radiator, drain the overflow, and refill with good, new antifreeze and distilled water at the correct ratio. After that, I will bypass the heater core and try and take it home without overheating. Once home, I will make sure the heater core isn't clogged, and check the water pump and thermostat.

I don't know if it's related or just coincidental bad luck, but the brakes on this car had also gone almost completely out earlier that day. I'd probably lost about 75% of my pedal. I'll make a separate post about that though, so there isn't so much to read and so I can put it in the right subcategory.
https://blazerforum.com/forum/steeri...23/#post612668

 

well, near 100 people have looked at this, but no one has responded. For anyone who might want an update, here it is:
I went out to where the car was left after it overheated. I went to drain the radiator, and maybe a pint of coolant came out. When I checked the levels when it overheated, it was very much filled. Maybe it boiled off, I don't know. Anyway, I bypassed the heater core and put new fluid in the radiator and overflow. I drove it a bit, and the temperature fluctuated all the way up to 3/4 of the gauge down to 1/4 of the gauge, and then rested at normal operating temperature. I was then able to drive it back.

Tomorrow I'm going to flush the heater core with CLR to break apart any blockage that may be present, and then I'm going to undo the bypass.

I have the rest of the week after Tuesday off. I'll probably check and replace the thermostat. It seems like it might be sticking or something. If I have time I'll do my pitman arm too.
Still clueless about the brakes though.

 

with the cooling system I would recomend doing a full flush, put one of those tee's in (from autozone) the heater line, than remove your block drain plugs, and flush the hole thing out really well including your heater core. Also I would buy a new thermostat, and cut the middle out of the old one, and put it back in during the flush, that way you can flush the hole thing really well and not have the thermostat blocking stuff. Those block drains can trap alot of gunk and stuff that you cant seem to get out doing a normal flush, there is one on either side, you should be able to see them from the wheel wells.

 

I agree with swells, do a system flush and buy and install a new thermostat. The other reason of why you have rust color in your fluid is because you have put water in the system (more water than antifreeze) and the first thing to corrode is the radiator. I know this because I done the same thing and learned the hard way. The corrosion from the radiator went into the water pump and then went into the heater core blocking it from producing heat. Also, it clogged up the thermostat causing it not to open up properly and letting coolant flow through the system.
I would flush the system, change out the thermostat and later down the road change out the waterpump and and radiator hoses and heater core hoses. If you don't then all the corrosion that is still in the system will eventually clog up again..(found out the hard way on that too).

Check you brake lines and make sure they are not leaking, if they are you could be getting air into the brake system. Check the brake fluid...are you using the right brake fluid? If everything is fine and you are using the right brake fluid then it might be you brake booster going out. But to me it sound like you got either a worn brake booster or air the line. If there is air in the line your pedal will feel spongy rather than firm.

 

Hey guys, while I agree with you that a full flush would be ideal, I don't think I can do it right now with the weather the way it is. It's -14 degrees with the windchill as I'm writing this, and it will not be warming up much tomorrow. Plus, there's several inches of snow on the ground. I think I may just have to only flush the heater core and get by on just that and the new fluid until springtime. I still haven't figured out the brakes because I haven't had much time to work on them. I started it up Tuesday and had my mom push the brakes while I looked for leaks, but I couldn't find anything. Honestly, I didn't even know where to look. I'm going to pull the wheels tomorrow and look for anything obvious, unless one of you has a better idea. I did notice a drop spot by the drivers rear wheel, but that could have just as easily been melted snow or a past oil stain. I don't know. I'm just about ready to take it to a mechanic.

 

Is your brake pedal firm or spongy filling? Check all the brake lines that run from the caliper up to the hardline. The line coming from your caliper is made of rubber with a braided line inside (not steel braided) they do wear out and will start cracking and splitting. You will have to move your brake line and check for cracks around the crimp. Check you brake fluid if its low your fluid is going somewhere so you probably need to find the leak and fix it and bleed all your lines to get all the air out, which can take some time depending on how much air is in the system.

 

Pedal is VERY spongy. Goes down and compresses about 80% on just air. I didn't get a chance to pull the wheels today. I worked on my cooling system and was borderline hypothermic after that. Hopefully I'll get a chance to do it tomorrow. I'm probably just going to try to do my pitman arm, and if I get that done I'll just take the car up to the shop for an alignment (never had one in the 3 years I've had it, and possible never in it's 14 year life). I'll tell them that while they've got it on the lift, to please look for any brake leaks. So hopefully I can get them to find the problem for me and then I'll do the work to replace it

Regarding the overheating, I undid my bypass of the heater core I reconnected the hose ends to the heater core, and detached the hose ends to the intake manifold. I then blew compressed air through both sides, taking turns with one end being turned into a catch jug while the other had compressed air in it. Nothing came out at first, possibly because it was frozen. I then filled the heater core through the hoses with water I heated up on the stove. I let that sit a minute, then flushed it out both sides with compressed air. I repeated that a few times, and then filled the heater core with CLR and let it sit around 10 minutes before flushing. Then I flushed the CLR out twice with tap water and one final time with distilled water before putting everything back together.

I then took the car for a ride. Remember, when the car broke down, it lost cabin heat but continued to blow cold air. This time it was blowing warm air, but even on 4 it wasn't blowing very hard. Also, while driving the temp gauge went up to about 7/8 of the gauge, that is, slightly below the red mark, before finally cooling down. One it hit that mark, it went back down to normal operating temperature very quickly, a drop from about 265 degrees to 195 within maybe 10 seconds.
What do you make of that? Bad, sticky thermostat? That's another thing that will be getting replaced tomorrow.

 

The temp spiking like that might be a sign of an air bubbling traveling through the cooling system. That would cause a spike in temp like that. I only ever had that problem once and shortly after that discover my intake manifold gasket was failing. I replaced that and the problem was solved.

 

Sounds like a bad thermostat. Also have you checked your water pump? It could possibly be going out. To check that look behind the pulley that holds your fan on. There should be a small hole in near the top of the water pump. when it is running if it is shooting water out of it or leaking then your pump is also going out.
My xtreme blazer blazer corrodid up from too much water in the system and less antifreeze. I ended up replacing all radiator hoses, heater core hoses, water pump, thermostat and had to flush heater core out. After all that still go little heat. I found out that my heater core is so clogged that is doesn't get the coolant in there for the air to pass through giving you heat. Haven't replaced it yet...whole dash has to come out for that.

 

After the CLR and thermostat change, the car's temp held much more solid. It wasn't rock solid, which I attribute to the aftermarket thermostat. I've seen lots of people complaining about everything but the ACDelco thermostat. This one holds me at just below 190, as far as I can tell by the gauge. The heat is present, but still blows weak and when switching the blend door position, it takes a few seconds for the air to switch. Blows harder sometimes than others. I don't get it. Anyway, it's operational, so I'm happy. Brakes are still keeping the car from being drivable though. Because of the snowstorm we just got hit by, it's impossible to check for wetness from brake fluid because EVERYTHING is wet. However, and I don't want to jump the gun on this, I MAY have seen some wetness between the master cylinder and brake booster. Still though, the brake lines look terrible, so I could just be seeing things, or possibly seeing something other than brake fluid that just happened to wet that area that I checked, such as coolant which drained out while doing the cooling system work. Still though, I'll look up if there are any ways to check the master cylinder for failure. It'd be much easier to replace that now and do the lines later with the weather the way it is.