B00STED Si

well it started last week when i was going to the mall, when i pulled in the parking lot i noticed that the temp gauge was about 3/4 of the way up, and usually its only 1/4 of the way up, so i immediately shut the a/c off and turned on the heat to pull the heat out from the engine bay, and it literally dropped down to the normal spot within 2 seconds. then again today on my way to my girlfriends house i was driving and i noticed it was up 3/4 again, so i did the same thing, turned the a/c off, turned the heat on, and it dropped back to the normal level. on my way back to my house, i left the a/c on and turned the blower on medium, and kept my eye on the temp gauge, and it would randomly go up, then go back down to the normal setting, then stay halfway for a bit, it was just all over the place. any idea what could be causing this, b/c its never happened before.

btw, i have 1/2 size radiator, hooked up with slimline fans mounted to the front instead of behind.

B00STED Si

???anyone????

DaveF

sounds like you have some air trapped in your coolant system. try running the car with the rad cap off for a good 15 minutes.. ive found that running the car, and shuting it off repeatedly helps get the air out, by getting the water moving, and than stopping it. the air will work its way out.

B20luda

air or a blown headgasket...or u could have a fooked up guage/ground

B00STED Si

yeah ill check for air, since i really didnt do that after i flushed and refilled the coolant when i did the engine build about 6-8k miles ago.... i doubt its the head gasket, theres no smoke at all, coolant is still the bright red color.... thanks guys

2000psi

air in the system.

B00STED Si

well i worked the air out of the system, let it run for a bit with the rad. cap off with a/c on and all to get the thermostat to open up, then topped it up, closed the cap and things have seemed fine since. how does air get in the system tho? could that be a sign of a blown headgasket? i mean im not seeing any smoke at all, coolant is still bright red.... btw how much whp/psi can an OEM headgasket handle? when i did my engine build i just used a factory headgasket kit b/c i wasnt sure how bad the aftermarket all metal gaskets were, i was told the majority of them leak oil, coolant, etc. and i didnt wanna deal with ne of that.

im gonna double check everything tomorrow morning, but where is the bleeder bolt for the cooling system located??? thanks.


Modified by B00STED Si at 9:43 PM 6/15/2005

2000psi

On my EJ6, the radiator cap is the high point so there is no bleed screw....I dunno if it's the same on the Si though. air can get in anytime coolant gets out. I got a ton of air in my system when i switched my intake manifold and spilled coolant.

M.A.R.C.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2000psi &raquo;</TD></TR><TR><TD CLASS="quote">On my EJ6, the radiator cap is the high point so there is no bleed screw....I dunno if it's the same on the Si though. air can get in anytime coolant gets out. I got a ton of air in my system when i switched my intake manifold and spilled coolant.</TD></TR></TABLE>

same thing happened to me. i was driving down the highway and my temp gauge was bouncing up and down like it had hydraulics lol.

also make sure you don't have any leaks. i switched to a pusher fan when i put my precision 750hp core on. well the car would run hot after a while in traffic or just driving aroudn all day but it wouldn't peg out and it wasn't consistent. turns out i had two leaks... one by the iacv, and one from the smaller of the two lines going to the intake manifold/head. i guess because it's been hot as ***** recently in FL and the combination of the bigger intercooler blocking the flow cause the leaks to finally become an issue.