How hot is too hot?

[American_Muscle]

I've had my '91 LX for about 4 weeks.
I've had problems with overheating.
Today I took it for a quick ride.
After about 5 mins the temp was at about 230.

I parked it and turned it off.
I opened the hood.
I heard a noise coming from the water pump.
There was steam coming from that area. I believe out of the top hole in the water pump.
I also touched the top black hose(passenger side). It was VERY hot.
I could barely touch it..and that was after only 10 mins of being on and after 5 mins of cooling off.

I already have a new t-stat but that's probably not what's wrong.

Maybe the water pump?

Thanks
Patrick

 

[DMAN302]

I run stock rad, 180 tstat, and new water pump, replaced fan clutch with HD unit, and fan as well. Mine never sees over 190 even during our little heat wave. 230 is WAY to high IMO..chech your fan clutch to see if warn, maybe a rad flush, and check to see if the air deflector under the front of the car is in place.

 

[Fishhawk]

On average mine runs 190. In the worst case in a traffic jam in 90 degree heat it has climbed to 210. 230 is way to high. Whats the radiator look like? Not a bad idea to install a new water pump and t-stat. Maybe now is the time to ditch the old fan a go with an electric.

 

[TheUser]

Are you using the stock gauge? Many have problems w/ inaccuracies w/ the stock gauge. A lot like to get a set of Autometer gauges to tell them what's really going on. That being said, I did just that and my stock gauge has been semi-accurate all along, but I still feel safer w/ the autometer's.

230 is way too hot, though. If you have steam coming from your water pump then I suppose that's a direction to investigate further. I'm not sure, but there may be some type of seal beneath that hole - confirm this - and if so, the seal may be bad. Not real sure on that though.

Make sure you "burp" the coolant system to get all of the air pockets out:
Jack up the front of the car (mainly the radiator neck) higher than the thermostat, pull your radiator cap off, star the car and let it run. Watch for it to shoot bubbles out and I generally set a catch pan under the car to catch any lost coolant. I keep topping it off, but I've learned that you really don't want to top it all of the way off until you're sure most of the bubbles are out - I like to keep it a couple inches below the top of that little cyclinder looking thing when you look straight down the radiator neck.

Also, make sure all of your hoses are clamped tight to prevent air sucking in/cooling leaking out.

Make sure your shroud fits up tight against the radiator. Does it overheat in city driving/highway driving (50-60 mph plus) or both?

 

[HISSIN50]

When you do the stat, check around and see what gives.

The upper rad hose being hard suggests that the stat was not stuck closed. And if stuck open, it should take a while to warm the motor up.

I would not really sweat 230*F if you have iron heads. The computer does not even shut down AC till 242*F IIRC. For example, on 94-95's, the high speed cooling fan does not come on till 226*F.

BUT that certainly does not mean that it is ok to run around that like - something is very wrong. Make sure the system is holding pressure too - the difference between a system at atmospheric pressure and one with 16 PSI is a boiling point which is ~50*F higher. Big difference to go from an effective boiling point of 212-220*F to 250-260*F.

Good luck.

 

[sunil6784]

Are you sure that the t-stat isn't backwards?

 

[Black1987Stang]

What i would do is drain cooling system, flush it REALLY good, change the thermostat!, the exact same thing happened to mine i had a thermostat it oped in a pot of water and everything but not in the car, poped in a new t stat and never overheated again, check to see if the water pump is actually pumping,

 

[HISSIN50]

FWIW, I am a big fan of the Mr Gasket thermostats. Balanced, opens fully sooner, and includes a jiggle pin.

I have read very favorable things about Robert Shaw and Stewart stats.

Good luck.

 

[American_Muscle]

Thanks for everyone's help.

See, the thing is a friend of mine drove the car home from the previous owner.
It was a 1.5 hour drive at constant speed of 90 mph over the German Autobahn.
According to him at the time, the temp was fine.
After we got back we cut the car off and it wouldn't start back up before we let it cool off for 30 mins.
According to the previous owner it does have a coolant leak. That's why he gave me a new water pump, because he says that's where the leak is coming from.
But that wouldn't cause the overheating.
I just have to frequently refill the coolant.

 

[Euphoric306]

if his upper hose was hot, tstat is basically fine, and water pump is pumping (maybe not enough pressure though, depending on the severity of it)

how frequently do you have to fill it up (and does it overheat right after u fill her up?)

might wanna check ur fan to make sure its working too

maybe clogged radiator, maybe, maybe, maybe



cooling systems suck, especially 15+ year old cooling systems which havent been taken very good care of