Idle problem and overheating

[slideordie_240sx]

ok so i just strated my sr up for the first time a couple days ago. i am having a horrible idle problem and it overheats after about five minutes. it gets so hot i can hear it boiling. and it will idle real high about 3000 rpm or real low to about 350 rpm. it also responds wierd when i touch the throttle. the rpms go up fast and come back down real slow. i neeeeed help!!!!!

[j00ni3]

at idle it overheats after 5 min ?

or after running it for 5 min ?

and... it can be one of many... search and you'll see

[Tex Willer]

Blown headgasket?

[smithers584]

coolant temp sensor possibly? like he said, could be many things, i know if you dont have enough coolant in then you can get air over the coolant temp sensor and that causes the rpms to flux, it will also do it if the sensor is bad. start checking everything! thermostat might not be opening, could be a head gasket, do a compression test and find out whats up. i know i have a knock sensor code which is pulling my timing and making my idle weird. could be a combination of things like mentioned, so start narrowing down what it is not.

[jdm_s14_zenki]

headgasket, or coolant temp, or thermo. my guess is coolant temp cus of your idle problem..maybe a combination of coolant temp, thermo, and air in your radiator?

[mjjstang]

I had tons of air in mine, then I popped the cap, and A WOOOOOOSH of hot ass air came out of my radiator (mind you this is after about 4 days of refilling to full then driving around, when I put my sr togather, it just took time to get all the air out) once I popped that cap and topped it off, and put the cap back on, my temp have been fine, but yah when I had the air in the system it would get hella hot hella fast and im not even from norcal. (in reference to my use of the word Hella)

[ka24deturbo]

If you have white smoke coming out of your exhaust then you have a blown headgasket, sounds like you need to bleed your coolant system. Take the screw off of the upper water hose outlet and run your engine and add water/coolant until you get a continuous flow from that hole, then put the bolt back.

[ledzeppelin240]

I would say head gasket because of the bad idle, overheating, and most likely no power, but if it isn’t burning coolant then it may be a few other things.

The thermostat may not be opening

There is probably a lot of air in the cooling system.
This would cause the faulty CTS readings, which would cause idle problems.

Over advanced or retarded ignition timing.

Blocked exhaust system.

Inoperative EGR valve, which would cause detonation.

[Tenchuu]

on a side note, i always wondered:

how hard is is to fill a SR right? i know that the RB has a nice little bleed screw up top and i picked up a funnel for $.23 and i filled mine fine about 4 times now.

[jdm_s14_zenki]

when i filled mine, i just ran it, filled it again, ran it, filled it...let it cool down of course before u pop the cap, but there was another time i ran it for a few days, then my temp shot up..pulled over, didnt see any leaks, then filled it again and it was cool ever since.

[slideordie_240sx]

its after driving the car for 5 minutes. ive already made sure that there is no air in the radiator. and yes there is white smoke coming out of the exhaust. my brand new spark plugs are black as hell. also there is only about 7 or 8 lbs of vaccum. but it does make power. i went up a 45 degree hill in fifth going about 25.

[smithers584]

ok well then you obviously have a huge vacumm leak, possible headgasket, thats probably the white smoke you see. i know sr's are supposed to be right around 20 lbs of vacumm at idle, your a little off.

[jdm_s14_zenki]

white smoke is steam. water mixed with oil in your cylinders. head gasket is blown.

think about it. white smoke, idle problems, over heating..you blew your head gasket. dont drive the car ANYMORE. you will probably warp the head as well. rip it all apart, change your head gasket, resurface your head (circular not vertical) change head bolts to arp if needed. clean the crap out of your motor. check to see if other things are damaged, valves, rocker arms can crack, ect..piston rings from overheating. pistons go bad if you over heat..all kinds of things man.

[slideordie_240sx]

its more like blue smoke and the more drive it the less it smokes and the less it overheats but i am still having problems with the idling

[Realnez]

If your spark plugs are black and your blowing out blue these are signs of bad piston rings or bad valve guide seals. Do a compression test then go from there, about the vacumme leak, have you double checked that everything is in the right place?

[jdm_s14_zenki]

If your spark plugs are black and your blowing out blue these are signs of bad piston rings or bad valve guide seals. Do a compression test then go from there, about the vacumme leak, have you double checked that everything is in the right place?
beat me to it.

for vaccum, do a leak test. theres a thread on this forum somewhere that shows you how to make one from home depot.