[rover7]

'95 4.0se

Driving down highway with heat set to 72 external temp 38. Warm air coming from vents like normal. I then noticed cold air coming from heat vents. I looked at my temp gauge and it was rapidly heading towards the danger zone. I immediately began to pull over but before I could come to a stop and kill the engine, the gauge hit red and coolant steam poured from under the hood. I killed the engine and checked under hood. The top hose that connects to the radiator had popped off. I was close to a gas station so after letting truck cool down I managed to make it there without the temp gauge going back into the danger zone. After reconnecting the hose and refilling the coolant I began to drive. Almost instantly the gauge headed back toward the danger zone. I killed the engine before it crossed into the red. After sitting for just a minute or two the gauge dropped to normal so I tried driving again. Once again the temp gauge shot toward the red zone. After killing the engine the gauge would go back to normal in just a couple of minutes but would head right back to the danger zone after starting the engine. Another thing I noticed was that the heater vents would only blow cold air. No matter how high I set the heat no warm air would come out of the vents.

Could this problem be a bad thermostat? What could cause the top radiator hose to pop off? In the morning I will start by checking and topping off coolant and see if I notice anything obvious such as leaks or other hoses that may have come loose.

I am over 100 miles from home so I would appreciate any thoughts or suggestions.

 

[kmagnuss]

You have a bubble in your system. You can handle it a couple different ways.

1.Take off the top hose and pour water directly into it...also make sure your overflow bottle is at the proper level.

or

2. Bring a few gallons of 50/50 with you and every time it starts to overheat, let it cool a bit, then fill up the resevoir. It will happen a bunch, but eventually it will take.

 

[kmagnuss]

Even if you do #1, I would keep a few gallons of 50/50 on hand just in case.

Be safe.

 

[kmagnuss]

Quote: ...and then I got a lovely splash of red coolant all over the garage floor when the air lock cleared

When refilling radiator, "a" trick is to use your EAS bypass system as follows: pump front susp to max height, set rears at "access".
( This ensures all air is expelled to "highest point" and reduces airpockets deep in engine)

Make sure cap is removed from expansion tank.
Remove top hose from radiator then decant () the proper red stuff (coolant, that is!) into the hose until you see the level begin to rise in the expansion tank.
Refit top hose to radiator outlet and start the engine, letting it warm up at a fast idle.
Watch for the bypass hose from top of radiator to expansion tank begin to dribble freely into exp. tank.
Wait for bubbling to subside.
Top up expansion tank only to COLD level, replace cap and switch off engine.
Let engine cool...it will then draw required amount of coolant into system from exp. tank. Level drops.
Deflate front susp to "access" so that RR is level.
Check coolant level in exp tank, top up to COLD ...DON'T overfill.

The next time the engine reaches operating temp, any excess air will be expelled through overflow with minimal loss (hopefully) of coolant. check when cool again and top us if necessary. Job done.

 

[rover7]

When I disconnect top hose to fill, I want to pour coolant so it goes directly into radiator until I see the overflow container filling...is that correct. When doing this it helps to have the front of truck higher than rear...correct? I will look for a slight incline to park while filling radiator.
Thanks for the reply and I'm going to give this a shot.

 

[kmagnuss]

Right on man. Good luck.

 

[Turpin]

rover 7 - sounds like a radiator that is stopped up. I have a 99 HSE and had same problem until I replaced radiator. Too much pressure build up kept blowing off hose. New radiator and all is well.

 

[RRToadHall]

One item to keep in mind, once your system is out of water/coolant your temp guage is useless. :evil: The temp guage will only register fluid temp, not air temp. So when you say you managed to get to the service station without it overheating... well chances are you were quite over heated as you had no coolant left. The general rule of thumb is that if you don't have enough coolant to get circulation to the heater core then you don't have enough to get through your engine block.

 

[rover7]

Thanks for all the input guys...your knowledge is of tremendous help. I followed the instructions on how to refill system if a air pocket is causing my issue. I only drove about 10 minutes or so, but the temp gauge stayed at a normal temp. I drive around a little more tonight to see what happens. On friday I have to drive home which is a couple of hours so I hope I can figure out if things are ok by then. I am worried that something caused the overheating and hose to pop, perhaps a clogged radiator as turpin suggested.

 

[big-t]

when you get the time, take your bottom hose off and your rad cap off and put a garden hose in the filler spout and let the hose run. If you get good flow out the bottom hose connector your rad is not blocked. `) You may have just had a loose clamp up top. Whenever replacing hoses always clean the spout on the rad and check the inside of the hose for slimy build up. I think Kmaggs is right, you have, had, air bubble in upper engine parts.

 

[dutchfrompredator]

this is uncanny. literally the same thing happened to me two weeks ago.

cruising along on the highway at like 65. nothing fancy. you know. suddenly my heater starts blowing cold while directed to the floor. i noticed it quickly b/c i enjoy driving with my shoes off and it was 20 degrees out. i think "that's unusual" and then notice the needle climbing crazy fast into the red. knowing fully the implications with an aluminum engine, i made my way over to the shoulder and pulled over. i was traumatized by seeing the red warning light pop on for a second as i got her off the road. by now she's smoking hardcore and i'm like F***! this is all i need...$$ :crybaby2: $$

i pop the hood and what do i see but the stupid hose from the engine to the heater matrix has become detached. there is F'ing boiling coolant spraying everywhere in the engine compartment and onto my jacket (thank god not my face or into my eyes). meanwhile the metal hose clamp is happily dangling there. i reattach the hose in the freezing wind and slip (b/c it's loose in the first place :dance: ) the clamp on and tighten it down with a screwdriver. then i heavy zip-tie above the clamp for peace of mind. i'm a fan of having coolant along, so it refilled it after it cooled, waited a while, and she fired up and has been fine since. topped off in small amounts over the next week. a/c back to normal and running at normal temp. no puddles under her in the morning.

thank god. ray:

 

[big-t]

Ya gotta love it when it's free and just somethin comin loose. :lol: :clap:

 

[dutchfrompredator]

you said it. not to hijack the thread, but this applies to both of us: what type of internal injuries, if any, could result from a rapid onset, but quickly resolved overheat like this? i've seen a post-overheat cheklist around here, and i seem to check out fine. i've had an oil change since then and that went routinely too so i guess i'm good to go?

 

[rover7]

update...more questions

So I took the Rover to a shop to have the cooling system looked at to see if there was an obvious reason for my overheat and popping radiator hose off. I was told that I had an internal combustion leak in the engine. Anything from a head gasket to piston sleeve or block. I decided to run it this weekend to see how quick it would overheat. I ran it with the idle up for a 1/2 hour and temp gauge stayed normal. A few hours later I decided to take it on a driving test to see how quickly I would again be stranded. I drove about a 1/2 hour and the temp gauge stayed normal again. My Rover seems to be running fine. The shop that checked it is a well known reputable one so I'm not discounting what they told me, but I am questioning how bad my combustion leak really is. I really don't want to spend the money to rip the engine apart only to find out it's not something easily fixed. The truck over heated on a 2 1/2 hour drive so I'm wondering if it was just a long pressure build up that caused my issue. Maybe I'll be ok on shorter drives. Anyhow...would it be worth my while to try something like BlueDevil to try and seal any leak? Is this stuff a waste of money or has anyone had any positive results?