Z28Noob

So i HAD a slight Over heating problem when i would be City driving(and beating on the car) hwy driving was fine. NOW i start the car and with in 5 mins its all the way pasted 260 mark!
the hose that feeds in the the thermostat dosent ever feel that warm but the water pump is with out a doubt hot as hell (does that mean the water pump is not working?"new water pump") and i cant get any heat out the heater core last week all worked fine. I bleed both bleeder screws and it bubbles out the over flow tank ever time

what i have done already:
Flushed all of the coolling system (now 3 times)
changed thermastat
cooling fans work perfectly
bleed the system of all air



Help with any ideas I dont wanna just start throwing parts at it

Z28Noob

ok to rephrase if im driving the car it takes 5 mins to go past 260
if its sitting at idle it take about 15 mins to go past 260. and if i have the radiator cap off when i first start the car its like a geyser comming out of it for about 15 secs i would guess and the hole time its running its steaming / bubbling
out the overflow tank and ther is no water in the oil i just checked that

ACE1252

Sounds like the water pump is not working correctly. Need to pull the pump and find out what is going on....but check on the following first....

Make you sure you bought the correct type thermostat.

Are you SURE all the hoses are in the correct place?

May not hurt to pressure test the system(cooling system pressure tester). I've got plenty of posts on how to use a cooling system pressure tester(search).

Make sure your radiator is clean outside and inside....no clogs on inside and make sure nothing is blocking airflow through the radiator. I've read of people getting a plastic bag stuck on the radiator that would block air flow.

Is the black air damn deflector under the car still there? If it's broke off, you will overheat very quickly.

shoebox

Lots of people have been mistakenly swapping the steam pipe hose with the reservoir hose, lately. Make sure you have not done that. When you fill the system, make sure you are using the correct procedure and opening the bleeder screws while filling. Most of the air is purged that way.

Sturbity

I'm not qualified bit you describing my car right now and it was the WP relatively cheap part just time consuming good luck. S

joelster

x2

Very easy to put those 2 hoses on backwards. They are the 2 tiny hoses that connect just under the cap. If you install them backwards it will push a lot of the coolant out in 5 mins.

aknight_sa

regarding the two hoses.. which one goes where?

Dave89IROC

And regarding the water pump, did this start with the installation of the new one? If yes, did you make sure to inspect(for worn splines) and install the drive coupler?

Injuneer

Shoebox has a diagram. Upper hose (on the cap neck) goes to the reservoir bottle. Lower hose on the radiator tank is from the throttle body (95-97 only).

http://shbox.com/1/95-97_hoses.jpg

5n1p3r

I had a similar issue and it turned out that it was a combo if things causing the issue, one of my heater core hoses had a pin hole leak and was spraying steam/coolant when the car would heat up. I didn't notice it for some time because of how small the leak was. I replaced it and it started overheating again after a couple days so I replaced the radiator cap and that fixed it for me.

Z28Noob

...head gasket coolant right in to the cylinder burning threw the exhaust

ACE1252

I hate to hear that.

How did you find it? Tear down or with a cooling system pressure tester(or some other way?)?

Last time I had something similar happen was on my 1990 3.1 Z24. It was either cylinder # 1 or 3 that developed a hairline crack.....it would pressurize the cooling system and blow coolant out the the overflow.