question about cooling system

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scotttttt1970
Posts: 5
Joined: Thu Jan 16, 2014 1:10 pm

question about cooling system

Unread post by scotttttt1970 » Thu Jan 16, 2014 1:39 pm

Hi mScott, and I have a question about my 2000 Chevy Crapalier. Well I started hearing the dreaded water pump sounds, as well as seeing some antifreeze coming out the weep hole. I preceded to change it and everything went well until a few days later when I noticed the temp gauge starting to get higher and higher. I panicked got the car home in time opened the hood and noticed the coolant was still full, and everything was running smoothy. No loss of coolant, nothing coming out of the overflow, no funky smell, and the car was running great. So I talked my neighbors friend and he said to change the coolant temperature sensor. So I did, and noticed the same problem. Well after trying these things I decided maybe it needs a good cleaning and flushing. Right now I am running super cleaner through the system. I still noticed the problem after running the cleaner for like thirty minutes, so I wiggled the pigtail connector wires that went to the coolant temp sensor, and immediately seen the gauge start to drop. So I replaced the connector, and here is were the question comes in. After changing the connector I started the car, and waited for it get up to temp, and the fan turned on earlier than it usually does, and car temp guage is maintaing a temp cooler then I have ever seen, and the, fan will not shut off after it gets cool, it runs the whole time, until I shut the car off. After I shut the car down, I start it back up and the fan is not running and will not until it reaches temp again, and then cools the car down and simply stays on. Any ideas on what might be causing this. Thanks in advance

 

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carriedi
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Location: Oregon

Re: question about cooling system

Unread post by carriedi » Thu Jan 16, 2014 4:04 pm

you should have hooked up to a scanner and looked at the temperature that the computer sees and compare that to what you gauge said. make sure that your heater is not on ac or defrost. that could turn on the cooling fan if the compressor is running. Have the heater on heat or in the off position. If you still have problems with the fan hook up t a scanner and see what the temp is and the fan requests. you may have a relay that could be sticking on. there are a few things that could cause the problem, narrow them down by seeing what the vehicle is doing with the inputs and outputs.

the fan shouldn't come on until the engine gets over 220F and will turn off around 195F to 210F. the gau(ge should show about 3/4 for the fan to come on and turn off just below 1/2 on the gauge (most cars) Normal running temp should be straight up or just under

scotttttt1970
Posts: 5
Joined: Thu Jan 16, 2014 1:10 pm

Re: question about cooling system

Unread post by scotttttt1970 » Thu Jan 16, 2014 5:17 pm

I am not sure of the exact temp the fan comes on at. I do know the middle mark is 195, and the fan comes on when it gets one mark past that. It cools to a little under the halfway mark and stays there with the fan running, and not turning off. It used to turn on on the second mark and cool down to the 195 mark and shut off. I was wondering if running straight water with the prestone super cleaner in it might cause some differences in temp. Also has mostly been done sitting and idleing. Anyways thanks for the quick reply and the good information.

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carriedi
Posts: 2280
Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: question about cooling system

Unread post by carriedi » Thu Jan 16, 2014 7:34 pm

I don't think that having water and your additive will make it so the fan stays on. (but stranger things have happened) Like I said before make sure that your heater isn't on defrost or ac. You might try finding your radiator fan relay and when you think it is cold enough to where it should turn off, tap on the relay and see if it turns off then.

scotttttt1970
Posts: 5
Joined: Thu Jan 16, 2014 1:10 pm

Re: question about cooling system

Unread post by scotttttt1970 » Thu Jan 16, 2014 8:05 pm

I have tried the tap on the relay thing, didn't seem to work, but I started the car up drove it until the fan came on, drove it some more, came back home popped the hood the fan was not on, and the temp was dropping like normal. So I let it sit and idle until it came back on, and it would not turn off just sitting there. I am starting to think clog more and more, or maybe I need to clean the radiator vents out. Seems to me while driving I am getting more air flow through the radiator causing it cool more allowing the the fan turn off. Just idling the fan isn't pulling enough air through. Sorry for rambling just my thoughts is all. Next question is can I pressure wash the vents clean or not? Thanks for all the help

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carriedi
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Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: question about cooling system

Unread post by carriedi » Fri Jan 17, 2014 1:33 pm

it does look like there isn't quite enough cooling at idle where as when you are driving you force more air through. putting a scanner on and watching the temp and fan operation while you sit still and then when you are driving could verify that. Also you could put your heater on high speed and hot temperature and see if that additional cooling will turn the fan off. Also it would let you know how the flow through the heater core is. it should get over 140F out the vents.

scotttttt1970
Posts: 5
Joined: Thu Jan 16, 2014 1:10 pm

Re: question about cooling system

Unread post by scotttttt1970 » Fri Jan 17, 2014 6:20 pm

Yep that's what I'm going to do. The only thing is that the engine has never overheated, even before I changed the water pump, and the temp gauge was pegged out. Who knows the wife is driving it right now and she said its doing great, she couldn't tell me if the fan was cutting off though. I'll check when she gets here. Thanks for everything, I will report back the results in a few..

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