Hello all new to the forums but been following this site for i while. Anyhow i own a 2004 Discovery SE7, recently i replaced the thermostat with a 180 and also replaced the reservoir cap. My temps on my ultra gauge have been around 210 highway and 226 traffic. After reading a few threads in this forum i decided to order a new radiator and see how that goes. I have been reading horror stories about dex cool so i figured its all clogged up. Now my question is can i flush the coolant out of the motor without the radiator being connected? where would i introduce water into the system? thank you

 

Be sure air path from grille thru the radiator and condenser and cooler packages is clear, no build up of grass, leaves, mud, road trash...

You can confirm radiator clog by measure temp on fins, top to bottom, in a vertical line, warmed up, engine off. Should be within 10F if clear. Clogs make lower rows cooler from low or no flow. You would disconnect thermostat, and attach hose to top radiator hose with a rag, in effect a reverse flush. Would be good to do the heater core reverse as well.

If radiator reads good top to bottom, may want to consider water pump.

At your temps, electric fan should be on. If not, blown fuse, siezed electric motor, fried relay.

 

Yes the electric fan kicks on at around 210 degrees. radiator condenser clear of any debris. fan clutch checks out ok. Forgive my newbness im not understanding the flushing part? if i disconnect thermostat i have 3 open hoses. i connect 2 together and put water in the third?

 

no leave all of them apart, make water enter the engine from the hose from top of radiator (radiator is disconected and both ends). Water goes into engine and out water pump. You'll have to block the hose that goes to top of stat. Stat has little holes in the top, don't want them full of crud.

 

Do you know how to verify the viscus operation, tell us how you did it?
As for removing all the old coolant, with the new radiator installed, fill your system thru the coolant bottle with distilled water till full, replace the coolant cap, start the engine letting it run for 2 or 3 minutes, remove the lower radiator hose, let it drain, reattach and do it one more time. Should take around 4 gallons on Distilled water.
Then using a concentrate, not 50/50 coolant refill the engine with distilled and concentrate coolant and bleed the system of air.

 

As for the viscous fan. with engine still hot i spun viscous fan and it went less than a quarter turn. also checked for water pump shaft play it checked ok. should i do flush with the old radiator on or the new one? just dont want to clog new radiator when i do flush. thanks again

 

You always want to compare the spinning resistance of the viscus when cold and hot, hot should be about two time more resistance.
As for flushing the engine of old fluid, do it with the new radiator in.

 

how long can i safely run the truck without the thermostat? i want to put a tee in place of the thermostat when i do the flush and possibly adding a bottle of k-seal.

 

You can't and don't want to when flushing the engine.
Last time, install the new radiator, use only distilled water to flush the engine, fill engine with distilled water, run the engine just a couple of minutes, turn it off, drain the system by removing the lower radiator hoe, reattach it and do the whole thing one more time at which point you just need to refill the system, bleed it and then recheck the level the next morning before a cold start.

 

no problem. just worried about clogging a new thermostat thats all