When my car is at idle, the fans would go on and water temp. would rise slowly. So i thought the thermostat must went bad.

Picked up Duralast Thermostat from autozone and got it installed. It took me like an hour to bleed out the air in the system.

I took it for a drive and noticed the engine was overheating after driving for like 5 miles.. i bled the system again, and made sure the coolant was full.
But the engine was keep overheating like crazy..water temp. hitting like 280 degrees..
Heater was working fine. No leaking from hoses.

i can only guess that something must be wrong with the thermostat..other than blew up radiator. But i didn't notice coolant dripping down.

help~

 

Do you have a pressure tester? If not swap out the thermostat and start there

 

no i don't. If the new thermostat is causing the problem, now i can't trust parts from autozone lol. Is there any other alternative other than nismo or mishimoto?

 

What happened right before it started over heating?

Sounds like air in the cooling system behind the thermostat. Without a spill free funnel it will take days to get all the air out. With the proper bleeding tools (spill free funnel) it will still take a little more than an hour. This engine design is very hard to bleed and any air left behind the thermostat will keep it from opening up.

If the car is idling and the engine warms up feel the lower radiator hose. If it's not extremely hot then that means the thermostat is staying closed and hot coolant isn't passing through. Air behind the thermostat.

 

what happened right before it started over heating..umm..temp. kept on rising..
If the air is still in the system, then isnt it normal to not get hot air coming out from heater? I get hot air and i don't hear air coming out from the bleeding valve(?) when i open it.

 

That just means you don't have air trapped in your heating core. That has nothing to do with an air bubble trapped behind the thermostat. Also, if it's trapped behind the thermostat it won't come out the bleed valve.

And as to my question about what happened before the overheating I mean did you have any services, engine problems, wreck the car, etc? Don't be a smartass or you won't get help on the forums.

 

If you had the overheat issue before and after the TS change I'd say the problem is elsewhere, water pump getting weak? Blown HG? Clogged radiator?

 

How many miles are on the engine?
what color is your coolant, how does your oil look?

 

i picked up new oem one from stealership. now everything is normal! the water temp actually dropped now !

 

I know this is an old thread, but for anyone having this problem, I figured out why the Duralast thermostat was giving you problems. I ran into the same issue, and after testing it, I found out that the thermostat doesn't actually open at a low enough temperature compared to the OEM thermostat, so it overheats before it's open at all, then opens a little later, but it doesn't seem to be able to catch up and cool back down in time. So don't buy the Duralast thermostat.

 

The other option is to get rid of the thermostat and run the car without one. I know people who do that.