I'm on the highway, listening to the radio, cruising along, when I look down at the temperature gauge and the temperature needle is buried in the red, the red overheat warning light is on, and then the needle plummets to cold, and red warning light stays on. I take the next offramp (1/4 mile later) to park the vehicle. Right before I park it, I hear a pop, lots of steam from under the hood. I park it, lift the hood, and the 3-way hose junction (to the left of the bleeder screw) has come apart from one of the hoses (and still is). I get the vehicle towed home.
The car also sounded fine when i was parking it.
I have a feeling I was driving it hot for 5 minutes at the most, but not more. I also DO know that the vehicle's coolant level was full when I started out.
(A) what do you think it is?
(B) long-term damage?

 

Obviously you will need to replace the hose and t-stat, purge the system of all air and then pressure test the system to see if it will hold 20psi for 30 minute.
Long term you don’t want to think about until you have tested the system and got your truck running again, it could range from no damage to you now own a boat anchor, worry about that after you get it up running again.

 

Heres the plumbing layout.

1. Because no history of coolant loss before, and this is the first time, is a good sign.

2. From RAVE:

Now you made it all the way to the top. Should have stopped, let truck idle, if not cooling down, shut off. Steam from water that boiled, pressure blew hoses off. But you did the safe thing, stopping on side of xway is always a risk.

Possible causes - bad hose / clamp caused coolant loss, resulting in over heating. Had to happen fairly quick. Could be plugged thermostat (see those little holes in pix) or heater core. Could be head gasket, although the norm is over heat again and again, etc. Could be radiator plugged with dexcool sludge (don't refill with that).

Path forward: Replace hoses, stat, re-fill with water (why waste coolant now), do coolant pressure test as described above. If holding pressure, then do an actual idle test while watching temp with a scanner. That way you'll see what the ECM does, one degree at a time. If overheat, there is a chemical test for combustion gas in coolant ($35 - $50) at auto parts store, maybe do to verify no HG leak as well (confidence in chariot used for SWMBO). Of course drain oil and inspect for milky coolant in oil.

No tick when running is very good, don't want slipped liner from overheat, and it can happen from just once.

If going HG route it is a DIY project that is about $500 in parts and machine shop work to skim heads. A warped head is one that is out of flatness over .002 inch, and the paper in your printer is like .0038, so that's not much.

BUT before buying the HG parts, or at least at a point where they could be returned, remove heads and evaluate the slipped liner condition, there are posts about this. It is rarer than greedy shops would have you believe.

Summary: Damn. Fix, test, maybe head gasket. Look at an Ultra Gauge for temperature alarms and better monitoring.

 

Going to buy a new thermostat and hoses now. Should I also do a radiator flush?
And if so, can I just do a quickie Prestone radiator flush like with my car or is it more involved with a Rover?

 

i wouldn't be worring about flushing it until you find the cause of your problem, when you have yes; you should flush the system and fill it with regular alumium safe antifreeze

 

Odds are you have toasted the engine, at least head gaskets if not a dropped sleeve.
You might want to send me your number so we can talk before you go throwing parts at it.

 

Changed thermostat and flushed it----needle stays buried on cold and the overheat warning light stays on even when I first start it up------whats up now?

 

after you changed the hoses and thermostat, and then filled the system with fluid, did you bleed the system? If not, you likely have air stuck in the cooling system. Do a quick search for cooling system bleed. It will take a while to get the air out. It may take a couple of days. Don't try the "running the truck with the expansion tank cap off" bleed, it makes a mess and you will end up frustrated. With the truck off, fill the expansion tank, then open the bleed screw located in the t on the hoses, allow air to exit. lift the expansion tank, with the cap off and allow the fluid to exit the hole where the bleed screw goes. Once you have fluid coming out, keep the tank raised and close the bleed screw. Reset the tank, fill it to the brim, replace cap, start truck, turn heater on high and let idle til you have heat coming from the heater vents. It should take 5 to 10 minutes. If the temp gauge rises above mid-level, turn off the truck. Check fluid level, listen for the "waterfall" noise out of the passenger footwell area. The Red Heat light is a bit of a concern. Don't know why that would remain on full time. Is it on as soon as you start the truck? You may need to do the bleed procedure for two or three mornings. Doing it as descibed, you must do it on a cold engine, with cold fluid. Good luck. PHil

 

yeah its on the minute i start the truck

 

So, since you don't know how to work on your truck, either send me your number as I suggested before or spend really big bucks and have it towed, not driven to a good shop. In the mean time quit playing with it before you cause even more damage.