Coolant problem

[240SX_89]

The problems is that every time im out driving my car for like a couple hours and i stop and turn it off the coolant starts to overflow and spills out through that little slit at the top. If anyone could please help me out, it would be much appreciated.

[nissan_240sx]

Do you over heat? how's the temp in the guage cluster? I'm guessing you have a bad radiator

[240SX_89]

I havent overheated yet. The temp in the cluster shows that its at normal temp.

[ricebike]

try the easiest 1st... radiator cap...

[240SX_89]

What do you mean the radiator cap.

Today i took my car out i was on the highway and the car starded to overheat i pulled over and the coolant started bubbling, had to turn the heat on just to cool the engine down. Also i was wondering if anyone knew what the black cilynder on the passanger side does because the connection on mine is fried its all black and burned

[nissan_240sx]

I can't really see, but it seems to be the wiper motor

Radiator cap is the little cap on top of the radiator, they can be faulty.
Also, check your thermostat. Is this the stock radiator?

[240SX_89]

what do u mean they can be faulty, do they leak or something?

Yeah its the stock radiator and also the small fan in front of the radiator doesnt work could that be part of the problem.

[-The Stig-]

Originally Posted by 240SX_89

what do u mean they can be faulty, do they leak or something?

Yeah its the stock radiator and also the small fan in front of the radiator doesnt work could that be part of the problem.

... that would be my first guess.

[nissan_240sx]

The purpose of the radiator cap is to control the boiling point of the coolant/water mix by keeping it under pressure, there is rubber around under the cap that seals the pressure, yes they leak pressure/fluid when faulty.

The small fan in front on he radiator is an electric fan I believe, try turning your a/c on and it should spin

[ricebike]

yup but do you still have the motor-driven raditor fan that's mounted w/ the fan shroud? how's the fan clutch's operation?

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after seeing that u overheated while on highway speeds, that won't be the problem then...
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you can test the cap w/ autozone's free rental tool... you can also test your whole cooling system w/ that tool while engine is cold: pump it up to 14-15 psi... see if system holds pressure... if not, start looking for the external leak while a friend keeps pumping that tool to maintain pressure.-----

if no leak, fan clutch ok, electrical fan motor in front of the AC condensor on pass side working, no leaking water pump, & rad cap's rubber gasket is sealing properly, then i'd start thinking about a clogged radiator, not working t-stat... when's da last time you had a coolant flush/replacement?
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you didn't say anything about milkshake looking oil or burnt/dark automatic trans fluid... if you overheated more than 1 time, i'd suggest replacing them as well... hopefully u didn't blow a head gasket

[240SX_89]

Originally Posted by nissan_240sx

The purpose of the radiator cap is to control the boiling point of the coolant/water mix by keeping it under pressure, there is rubber around under the cap that seals the pressure, yes they leak pressure/fluid when faulty.

The small fan in front on he radiator is an electric fan I believe, try turning your a/c on and it should spin

I took the cap off and the seal didnt look crack or anything. When i took it off the coolant started to overflow, is that suppose to happen.

I turn on the a/c and it didnt spin at all, nothing happend.

[ricebike]

ac fan doesnt come on unless the sensor on the bottom radiator hose detects temps of ~208 degrees F... you can by pass the sensor by hooking the ac fan directly to battery/ground to test it.
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how's the other conditions i listed on my earlier post?

[Chuki_breath]

or it could be a worse case scenario. BLOWN HEADGASKET!!!!!!! I drove with one for about 2 months.......my car did everything your saying is happening to you. Id all park at school with my overflow reservoir boiling and steam rolling from under the hood. Me and my friends would just walk in like nothing was wrong whahhhahahahahaha. SHould of seen the stares from people we would get. priceless.

[240SX_89]

Well last night on my way to a party the car started to make some loud banging noise i come to the stop sign and the car shuts off . I checked the oil and had it none, so there is a leak somewhere. I just added two quarts a few days a go. When I put the car up on the ramps this morning and there is oil all over everything underneath strating from the oil pan on back. Today or sometime this week me and a freind are going to take it apart and see if we can find whats wrong with it.