[ImperialCrown]

I have seen it happen although one would think that radiator cap would be rated to relieve pressure and blow-off at ~15 psi.
I have also seen the ATF cooler fittings blow out of the plastic radiator.
I would borrow a cooling system pressure tester and pump the system up to 15 psi and try to wiggle the upper hose to make sure it is secure.
Plastic radiator nipples seem to be 'slippery' sometimes. Maybe a new upper hose will 'grip' it better. Watch for any further 'hot, pressure build up' signs of a head gasket leak.

 

[AllanC]

The upper radiator hose was replaced about 2 years ago though it is very evident that on the end that attaches to the radiator, the spring clamp has forced a set pattern in the hose. I will have to make sure I get the clamp back into the grooves that are set. I added a worm drive clamp for extra clamping force. So now just drive it and watch for any tell-tales signs of head gasket leakage. Hope I dodged bullet on this one again.

Thanks for the suggestions.

 

[Guest]

The rating on the radiator cap is for boiling point. Water boils at 212 degrees. With adding pressure to the system we can increase the boiling point 3 degrees for every one pound of pressure. Thus in this case we increase the boiling point 45 degrees. That doesnt mean the cap is the fail point for a over pressure situation. Its sole purpose is to increase the boiling point of the antifreeze mixture.
Your hose may have blown off at 12 psi or even 10 or less as I assume your tstat if stock still opens at 195. Somewhere you have a restriction building up pressure. Hopefully it was just a failed install on the hose prior but i bet you have a restricted system which is increasing pressure. Radiator, heater core and tstat are all possible. I dont know if i'd go down head gasket world. Make sure you do not add any stop leak or this will make the situation worse. Keep an eye on coolant temps> the only way to check for restrictions is to use a temp gun and know what each thing is supposed to be. For instance heater core should be hot on both hoses, so hot you can barely keep your hand on them. Upper hose to radiator should be 195ish and lower will be cooler unless radiator is restricted. If upper hose never gets hot check tstat .

 

[mechmanbri]

I was driving my 2003 Dodge Neon with 2.0L 4 cylinder engine, odometer reading 214,000 miles. Cruising at 65 mph with no problems and then I noticed that the temperature gauge was starting to climb. Outside air temperature was around 30 deg F and heater was working properly. By the time I safely stopped the vehicle the gauge had pegged at HOT. I opened the hood and noticed the top radiator hose had separated from the nipple on the radiator tank. The nipple was not cracked. So the overheating was caused by loss of coolant.

I have been driving cars, trucks and tractors over the course of 40+ years and I have never had a top radiator hose slide off the nipple on the top radiator tank. The original issue spring clamp was still on the hose. I am thinking that sufficient pressure developed and the spring clamp could not retain the hose??? There is a bump or raised area on the nipple that is suppose to keep a hose clamped and from sliding off.

I reinstalled the hose and added coolant to the system. In addition to the spring hose clamp I added a worm drive hose clamp to make sure the hose does not separate from mounting on the nipple. Is it possible that the spring clamp could loose tension and allow the hose to blow off?

I am wondering if the head gasket is starting to fail and allowing excessive pressure build up in the cooling system and causing the hose to separate from the radiator? I will drive the car and if the top hose separates again with a worm drive clamp then I must be getting excessive pressure. Anyone have this happen with a top radiator hose on an engine?

 

[mechmanbri]

My 2000 Dodge Neon had overheating issue since around March of this year. Even though had one so-called mechanic friend repeatedly claim it was partially blown head gasket, car showed no signs as such.

All started with an upstream O2 sensor needing replaced. Then I heard gurgling noises a couple times after driving at interstate speeds. A couple weeks later, I noticed temperature rising above halfway mark, but still nothing too serious. Gurgling noise traced to overflow tank which turned out to have hole in bottom of plastic reservoir. I used bondo to fix 2 small holes (no aftermarket tank for my car). Over the next couple months, I replaced thermostat and flushed radiator. This was nasty - looked like orange paint, actually stained driveway.

My wife, God love her, wasn't paying attention and totally ran the car out of water. Turns out the bottom, fat hose came off (just like in your case). Not trusting that 14-year old spring clamp, I replaced with worm drive hose claim. I think this was 3rd gallon of antifreeze consumed. By now, car overheating almost to high range, especially if AC was on. I then noticed my electric radiator fan wasn't working. Removed and tested it, was totally seized. Had to order new one ($60 aftermarket unit not compatible and was returned) for $115! Car still overheating but not more than 3/4 of the way. Avoided using AC, which was tough as now summer was upon us - ugh!

In the middle of July, I replaced radiator for $90 (got on sale online through Advanced Auto). Now car not overheating at all for first time in 4 months!! But ... car started with idling problem so I have yet another hill to climb it seems.

Hope my story was of help to you.