Overheating issue

[GZ20_finn]

Hey to all, im Ben and im a newbie to this site.. i drive a 1988 GZ20 soarer, im currently going through a big overheating problem.. which i thought was the thermostat, which ive taken out and still the problem is there, i have noticed however that one of the fans doesnt work.. its the little one that sits behind the radiator.. would that be the cause of all my grief.. any advice would be much appriciated..

thanks guys,

Ben

[doobs]

A bit more info on the overheating issue might be helpful, eg, when it happens? are you loosing coolant?

The little fan you asked about is probly for the aircon, and only works when the aircon is on.

[The Real Roadrunner]

welcome to the forums GZ20 finn,

best advice i can give you is search thru the forums.

there have been about 3 or more threads in the last month covering the same/similar topics, check thru them as there is some very good info and it saves ppl answering the same question all the time.

if after that you cant sort it out let us know what youv'e done and what the car is doing with a bit more detail and it will make the problem easier to figure out.

cheers
linden

[GZ20_finn]

there is no visable leaks anywhere.. the problem is, whenever i drive it after about 15 min or so.. the temp sky rockets.. so i pull over and have a look and the coolant is boiling, steam and jets of water are comin out of the overflow tank.. it used to only over heat when i was stopped at a set of lights, but once i started driving again the temp would go down.. now its gotten really bad..

[KARNAGE]

Well since it used to only overheat at the lights the fan is definately one reason but when your driving it should be fine. have you tried flushing the system out? what does the radiator look like, condition etc?

[kemicalx]

Once it's up to operating temperature you could feel with your hand (or better still use a laser thermometer) for/hot cold spots across your radiator core for an indication if any of the tubes are blocked with gunk. It's pretty likely that your system is just gunked up and just needs a back flush.

You said you couldn't see any leaks? Is there any chance you can get your hands on a pressure tester just to make sure?

I'm unsure of the belt layout and tensioning on a 1g but is the water pump belt tight?

Also worth checking your radiator cap condition, though even if it isn't holding pressure, that won't be the cause of high temperatures.

Failing all that, TK test maybe? Perhaps it's gone the way of a 7M?

[pisso001]

Id put a new thermostat back in it as it wont help not having one in it all all, Probably make it worse...

Thanks,

Chris.

[kemicalx]

If he's not running a thermostat, it's not likely to make it worse, but it's not wise to be running your car without one.

[jfallen]

I'm suprised that noone has mentioned a possible BHG.

Jordan

[kemicalx]

Failing all that, TK test maybe? Perhaps it's gone the way of a 7M?

.

[The Real Roadrunner]

If he's not running a thermostat, it's not likely to make it worse.

you would be suprised how much worse it can actually be. at least punch the guts out of the old one and fit the outer section back in as you NEED something to regulate max water flow

cheers
linden

[kemicalx]

yep fair point linden, but in this situation i don't think it's the problem.

[doobs]

How is the car running other than the overheating? Is there any smoke at all?

[GZ20_finn]

Other then the overheating the car seems to run great.. i did notice today that when i turned the car on and reved it, it spat water all over my brothers car.. and i only took the thermestat out to see it it was dead.. i do plan on gettin a new one

[jfallen]

wather out the exhaust is a sure sign of a blown head gasket

Cheers
Jordan