overheating problems

[K240]

My 93 240sx is overheating, i have no idea what is making it overheat, because i have replaced the whole cooling system, any one know why it is still overheating?, here is the list of things ive done to it.....

-New radiator, it is a koyo, but only a single row, and it isnt aluminum.-new water pump

- new thermostat, when i bought the car , there wasnt one in there.... -new radiator hoses

-took off the mechanical fan, and the electric fan he had on it.

-replaced them w/ Dual flex-a-lite fans.

it is still overheating.... What is going on?

[navysnail]

bleed the system, there is a plug on the intake manifold that you remove, then fill the radiator, then plug it back up when it flows out the hole.

you might also try a new pressure cap

[K240]

I have bled the system many times, and i have a new radiator cap too. any one else?

[K240]

bump!

[CiPHeR_Tx]

sometimes my temp gauge pegs out when my a/c is on....car doesn't overheat tho...i got all new cooling system also, radiator, thermostat, electric fans, hoses and cap

[yellow_jacket]

could be a cracked head or blown head gasket. Run a compression test.

[lost93]

i had the same problem it got really hot one day. bled the system one more time . i was about to give up but thats what end up fixing it.i had done everything you did to your car and also had just canged the head gasket and timing chain. so i thought maybe the head was do tight. so don't give up man.

[K240]

yeah, it is definitely the head gasket, i noticed white exhaust, and hydrocarbons, in the coolant...=]

[Neil]

I bought my 93 at 183,000 with this problem. Before i knew it was head gasket, though... i was doing research and found that a LOT of KA24DE's left Nissan plants in the early 90's without proper head torque! when i removed my cylinder head a few of the studs were merely finger-tight. I wondered how it lasted that long. The head was checked for tolerances and put back on with a FelPro gasket set. No problems in 2000 miles... except the car pings like crazy even with 93 octane and hooking up the EGR system only makes it worse.

[K240]

my neighbor thinks that i should retorque the head bolts too....what do you guys think?

[kevinatCandR]

How hot is it getting?How much antifreeze are you running ?

[K240]

sometimes it will heat up, sometimes its fine....1/3 coolant, and 2/3 water...

[kevinatCandR]

You can all ways run just water and a water conditioner. I have seen just that to nock 10-15deg out. I your case it may be worth 5-10 deg, since you are all ready running a 2/3 mix. I still would bleed it again, try jacking up the side of the car the bleeder is on while you top it off.

[Neil]

I wouldnt just retorque the head... To get at the studs you need to remove the cams anyway which means farting with the timing chain system no matter what. When I had my head off i inspected the head gasket and it was obviously in need of replacment. Where the combustion gasses had leaked past into the water jacket, it wore away at the gasket and i definitely wasnt confident that retorquing would fix it. The felpro set was about $90 at autozone, it came with everything i needed (intake/exhaust manifold gaskets etc) and felpros you dont have to worry about retorquing later as opposed to the necessity of retorquing most new OEM gaskets after 1000 miles.