If hes idleing it would blow the hot air back through it. which is when his problem is occuring.

 

at idle the air isnt moving at the radiator

 

yea... untill he turns the fan on. if it was backwards it would blow hot air from the engine into the radiator causeing it to get hotter.

That would explain the temp jump when he turned it on, But not the erratic temp gauge.

 

im surprised no one has said it but 200-210 isnt fine. its should be running around 170-180

 

lowbody:i thought you were talking about air coming through the radiator from the front

 

damn this thread is starting to remind me of work. "autozone"

first thing was there any work done to the car prior to this prob? rad, rad hose, heater hose, bypass, thermostat, thermostat housing, heater core, head gasket or water pump? seriously. the more info prior the issue. the better answer we can give ya. well at least some of us from the looks of it.

~if anything above was done. Did you bleed the cooling system properly? there can still be air in the system causing issues. 240's have a slight issue w/ air getting caught in the system. "rad sits about even w/ the motor" easy way to resolved that is to pull the car on some ramps of on a slight incline. open cap turn heat on full blast start car. add coolant as needed. until you don't see anymore bubbles.

~will agree w/ 170k240 temp is high according to www.alldatapro.com temp should be at 170. So that might be an issue to address as well. hopefully not something gasket related. "btw dont ask for the user name or password cuz i aint given it up"

~ i don't think the fans are an issue here how ever this is the easiest way for you to visually see if the fans are going in the right direction. take a lit cigarette w/ the fans running. place it in front of the car. if you see the fans pulling the smoke into the engine bay. you sir have the fans wired correctly.

any ways im going back to bed. jus woke up to hearing the aim thingy going off.

 

the fans are deffenetly pulling air threw my radiator. I have them mounted inside the engine bay and they pull 1,800 CFM per fan threw may rad, It blows you hair back standing by one of my fenders lol. Maybe the water pump is Shitty? or is it one of those situations were its either crap or not crap with no inbetween. I should really invest in a aftermarket rad and a nismo therm. I always seem to loose rad fluid also, but to my knowladge my radiator is not leaking. it happens when i dog on the car, I park is and like I noticed one time that I had a puddle of water under my car when I drove away later. In general it looses water some how also, but when parked on a hill and filled properly it still stays at 190-210 degrese. Sorry, really stupid problem, million situations for a fix. heating issues on a car really blow because theirs like a thousand senarios.

 

I'm betting on air in the system. As an air bubble goes by the sensor, it will cause it to tweak out. That would probably explain the tweaking needle.
As for the running hotter at idle etc, I would bet there is crap in the system. Have you tried a decent flush yet? If there is all kinds of crap in the system then it will limit the flow of coolant and make it run hotter.
The water pump might be going bad. You would have to figure out where the water is coming from exactly. There are little holes on the sides of the water pump. It will leak from those holes when the pump starts to go bad. Sometimes the water pump will go from good to dead in a day, other times it takes months.
Start with air in the lines and gunk in the system. By the time you flush it out and fill it up and work on getting all of the bubbles out, you ought to fix your problem.

 

basically what i was getting at.
i just dumbed it down some.
but at idle, it would be blowing hot air back.


how about.
use a clutch fan.

 

im not going to sit here and proofread your post history, but theres been at least 3 times this week ive read your post and just shook my head.

you even contradicted yourself just in this thread.

not really trying to be a dick, but if you dont know, you arent helping, and are causing someone more of a headache.