overheating problem 1 hose hot 1 cold

[cabbo3]

Hi ive got a 99' VT V6 and lately has been overheating the fans are working fine the coolant was abit dirty so i flushed the system and changed the thermostat as well but still overheating, the top hose which comes out of the motor gets really hot but the bottom stays cold.
Im thinking the coolant isnt circulating into the motor when i flushed the radiator the water came out the bottom fine so its not blocked the only thing i could think of it being is the water pump anyone have a similar problem or know what it could be ????

[spirto]

To quickly check the water pump,

- remove the housing.
- remove the thermostat (leave it out)
- replace the housing fill with water.
- run the engine, let it run for 10 min.
- slowly open the radiator cap
- rev the engine, should be seeing a flow of water.
- no flow = dodgy water pump.
- if the heat is now top and bottom hoses, could be a bad new thermostat
replace and hopefully fix.

hope this helps

[vt s]

The temp your feeling in the two hoses is normal.

The top hose is hot because thats the hot water coming from your engine while the bottom hose is supplying the water which has been cooled by the radiator hense why its cooler.
Are u losing any collant at all or pressure tested it?
Anyway if ends up to be water pump will be fairly easy to replace.
Goodluck

[commsirac]

The temp your feeling in the two hoses is normal.

Not in a car that is overheating.

Does sound like a circulation problem.
Could be water pump and/or radiator clogged.

one test to see which is to turn the heater onto max heat and low fan speed and compare the temp of the water going in and out of the heater. If these hoses display the same trait, one hot, the other cold, chances are water pump has had it. If both relatively hot, maybe radiator clogged, but you say it drained easily, if it drains completely within 2-3 secs its good, over 5 secs, suspect.

A restricted thermostat, maybe, but the problem was there before you changed and you have a brand new thermostat....could be installed back to front?

[clubsport_replica]

i was going to say thermostat not functioning but you have changed it, but yes could be upside down and not opening properly.

and yes before the thermostat opens top hose is hot and bottom cold and once it opens the both equalize

[banga]

you will probably find that about a 1/3 of your inlet tank is blocked with mud/scale . if your pump is fine then yank the radiator out and take it to a radiator shop for a clean , putting a hose through the radiator while its in the car does absolutely nothing , it may clear some dirty water but the hard dirt/scale will still be in the tubes