jb904

my 98 LS400 is acting up.....while driving with the A/C on the temp gauge rises above normal and keeps going up unless i stay at a constant speed. any slowing down or stopping and it keeps climbing. driving faster to increase the air flow helps and as soon as i turn off the A/C it drops down in a matter of seconds. i've checked both fans, radiator fan is on contstantly and the A/C fan only turns on when the A/C is on. water pump/thermostat have been changed out. coolant has been flushed and filled. im guessing pressure test is next along with havin my radiator checked out for clogs. is there anything else that my be the culprit? FYI not sure if this ties into my problem but the other day i noticed that my heater doesnt blow any hot air are the two somehow connected and causing my problem?

steveski

I would think bad thermostat. I wonder if the new one you had installed is designed to fail open? If so then I would bet you have air in the system and it needs to be bled. My 350Z did the same thing after I did a flush - I bled the air out and it was fine.

PureDrifter

iTrader: (10)

bad thermostat and/or big *** air bublbe in your cooling system.

qewani1

am having the same isuue on my ls400 2000 model, but i also noticed that coolant leaks from upper of the radiator.

What could be the problem? do i have to buy new radiator or is it something else? any input would be great help for me.

avalon42

iTrader: (1)

Top of the tank is busted. You can try silicone if you wish (some have done that here), but I would get the radiator replaced (along with a new thermostat).

qewani1

thanks avalon42. Today i just replaced the radiator with a new one.

AzHotLS

iTrader: (1)

Just don't tell us ho much (little) it cost you. We'll all be jealous.

avalon42

iTrader: (1)

I know. His new radiator is made by sweat shop children for a nickel.