Ok. I finally got my 1995 S10 back together Saturday after replacing the intake manifold gaskets. Now I have another problem. When driving my truck to work in the morning it warms up in a reasonable amount of time, but the temp climbs past to about 220 - 230 degrees. Then the temp drops pretty quickly back to 150 degrees. I tried to bleed any air that might be trapped in the coolant system. Is there really a proven way to bleed the system? Could it be a themastat issue sense I replaced it while I had it apart? Another idea that I heard from my father was something might be wrong with the cooling fan. I know the cooling fans GM used in the S10's are known to be quite loud, but honestly I have not been paying that much attention to listening for it. It is a mechanical fan with a clutch. Is there a way to check it? If you have any other ideas please let me know.
cooling problems
- Thread starter Swats
- Start date
dave89iroc
Club Member
if all the air is out, sounds like a thermostat issue, get it warrantied
steve581581
Club Sponsor
make sure your fan i working and if you dont have a high point to bleed the air out of the system i always take the upper radiator hose from the gooseneck and fill it from the hose... it works for me anyways
prostreet377
Forum Member
sounds like you have air trapped in the cooling system?
Tom
:icon_ques
Tom
:icon_ques
StangNut86
Club Member
if the radiator cap isn't the highest point in the system, undo the hose that is the highest (heater hose, radiator hose, etc) and fill till it overflows. that usually works well.
also, most GM cars/trucks have a small bleed valve in the cooling system just for this purpose.
also, most GM cars/trucks have a small bleed valve in the cooling system just for this purpose.
Exgmguy
Club Member
You absolutely have air in the system.
Try warming the engine with the cap off until the thermostat opens Then fill the coolant up while it is still running. The new cold coolant might cause the thermostat to close again, so let the temperature stabilize.
Idle the engine up by hand and top the coolant off.
Try warming the engine with the cap off until the thermostat opens Then fill the coolant up while it is still running. The new cold coolant might cause the thermostat to close again, so let the temperature stabilize.
Idle the engine up by hand and top the coolant off.
update
It has been a couple of weeks. I took of one the heater core hoses, from where it enters the firewall. I poured some coolant down the hose and coolant would come out of the now open end of the heater core. Because of the heater core being so high I am pretty sure the system did not have air in it. I drove the truck a couple of times and the temp would still climb to the 220 range during first warm up. The truck sat for a about a week because I went out of town and the holidays. Yesterday my father suggested the idea about the radiator cap be bad. So I swapped the cap from his S10. I took the truck for a short drive and climbed to about 210 and dropped back down to about 150. Today I drove the truck to my local grocery store and back. When I got home the smelled coolant. So I started looking for a leak again. I found some coolant on the lower radiator hose and around the crank pulley. I am thinking that the water pump is now starting to leak. Perhaps that could be the problem? That maybe I might have dropped a piece of gasket down the passage and it got the water pump?
It has been a couple of weeks. I took of one the heater core hoses, from where it enters the firewall. I poured some coolant down the hose and coolant would come out of the now open end of the heater core. Because of the heater core being so high I am pretty sure the system did not have air in it. I drove the truck a couple of times and the temp would still climb to the 220 range during first warm up. The truck sat for a about a week because I went out of town and the holidays. Yesterday my father suggested the idea about the radiator cap be bad. So I swapped the cap from his S10. I took the truck for a short drive and climbed to about 210 and dropped back down to about 150. Today I drove the truck to my local grocery store and back. When I got home the smelled coolant. So I started looking for a leak again. I found some coolant on the lower radiator hose and around the crank pulley. I am thinking that the water pump is now starting to leak. Perhaps that could be the problem? That maybe I might have dropped a piece of gasket down the passage and it got the water pump?
Exgmguy
Club Member
You still have air in the system as well. You need to bleed it properly. Also, when changing any gasket that sees coolant, you need to be sure the surface is 100% clean. Antifreeze will leave a slick residue that will leak every time.
A leak down the lower hose may possibly just be a loose clamp. Get under there with a flashlight and have a close look. Water pumps do have a "weep hole" that coolant will drip from when they start to go bad. That hole is usually located in the casting, somewhat buried behind the water pump pulley.
A leak down the lower hose may possibly just be a loose clamp. Get under there with a flashlight and have a close look. Water pumps do have a "weep hole" that coolant will drip from when they start to go bad. That hole is usually located in the casting, somewhat buried behind the water pump pulley.
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The lower radiator hose was dry near the clamp. I don't think the leak is coming from up high. It looks to be dry around the intake manifold. I bleed the cooling system a few times. By using the method of removing the cap, letting the truck warm up, wait until the thermostat opens, the coolant level will drop, top it off, and replace radiator cap. I think the coolant is coming from the water pump, and it is dripping down onto the pulley and getting thrown over the passenger side of the engine compartment. Could the water pump be a factor in the temp be screwy? Thanks.
The lower radiator hose was dry near the clamp. I don't think the leak is coming from up high. It looks to be dry around the intake manifold. I bleed the cooling system a few times. By using the method of removing the cap, letting the truck warm up, wait until the thermostat opens, the coolant level will drop, top it off, and replace radiator cap. I think the coolant is coming from the water pump, and it is dripping down onto the pulley and getting thrown over the passenger side of the engine compartment. Could the water pump be a factor in the temp be screwy? Thanks.
