Overheated, Fan issue, Radiator

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ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Fri Aug 18, 2017 5:59 pm

RRoller123 wrote:Check the ground coming off of the fan switch. Its connection is over in the cluster on the driver's side fender well. The switch input side from the fan is always hot, the switch gives it a path to ground. Thus it can run when the ignition is off.

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Thanks, done for the day. Will check it out tomorrow.

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nelsonj
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Re: Overheated, Fan issue, Radiator

Postby nelsonj » Fri Aug 18, 2017 8:52 pm

It almost certainly is the ground. Clean the connection on the ground pod. There should just be one wire that leads from the thermo switch to the ground. If that doesn't work, add a new ground wire.
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ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 19, 2017 5:58 am

Excuse the dumb question, but would it still be a ground issue if when the fan wire connectors are shorted together in turns on?
Last edited by ylbill on Sat Aug 19, 2017 7:41 am, edited 1 time in total.

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 19, 2017 7:37 am

sorry, ignore this post. i meant to edit last post.

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RRoller123
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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Sat Aug 19, 2017 7:48 am

If you short across the fan switch and the fan turns on, then either the fan switch is bad, or it isn't getting up to temperature because of air blockage in the radiator.
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ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 19, 2017 8:09 am

RRoller123 wrote:If you short across the fan switch and the fan turns on, then either the fan switch is bad, or it isn't getting up to temperature because of air blockage in the radiator.
This is becoming more of a mystery now, because I just installed a new switch and checked bottom hose and it was hot. I do believe the original cause was air blockage, which resulted in overheating, but have been checking that hose along the way and it has been circulating through that bottom hose. Thanks for all the input guys. Not sure where to go from here?

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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Sat Aug 19, 2017 8:35 am

How hot? It should be too hot to hold. If it is not, still probably air in the system.
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 19, 2017 8:53 am

RRoller123 wrote:How hot? It should be too hot to hold. If it is not, still probably air in the system.
Okay that I haven't paid enough attention to. Will be my next test. Thanks!

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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Sat Aug 19, 2017 12:00 pm

To be absolutely sure, jack the front end way up so that the fill plug at the union up front is the highest point, and massage the various hoses to work out all the trapped air. Make sure that the TStat is in the right orientation too. That would send coolant the wrong way and cause overheating of the engine, and likely under heating of the radiator. :?:
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sat Aug 19, 2017 2:01 pm

RRoller123 wrote:To be absolutely sure, jack the front end way up so that the fill plug at the union up front is the highest point, and massage the various hoses to work out all the trapped air. Make sure that the TStat is in the right orientation too. That would send coolant the wrong way and cause overheating of the engine, and likely under heating of the radiator. :?:
The Tstat hasn't been touched and the car has only had fan issues because of trapped air. I would burp the system and the fan would work fine. It's only since the car overheated that I'm having a fan problem not coming on even after burping the system, which is why I changed out the switch. I needed to do a flush anyway, so it worked out. I'll try to clear the air again when I get a chance and pay more attention to how hot the hoses are. Thanks

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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Sat Aug 19, 2017 6:56 pm

Maybe there is a small in-noticed leak somewhere? Does the level drop slowly over time? A slow leak will let air slowly in.
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 20, 2017 5:20 am

RRoller123 wrote:Maybe there is a small in-noticed leak somewhere? Does the level drop slowly over time? A slow leak will let air slowly in.
Not that I can visually see. I did block test after the overheat and no color change. I'm not real experienced in engine mechanics. Can do the basics. I enjoy driving it much more than working on it. :) Going to burp it, check fluid level and see how it goes from there.

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 20, 2017 5:21 am

ylbill wrote:
RRoller123 wrote:Maybe there is a small in-noticed leak somewhere? Does the level drop slowly over time? A slow leak will let air slowly in.
Not that I can visually see. I did block test after the overheat and no color change. I'm not real experienced in engine mechanics. Can do the basics. I enjoy driving it much more than working on it :). Going to burp it, check fluid level and see how it goes from there.

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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Sun Aug 20, 2017 5:59 am

good luck!
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 20, 2017 3:37 pm

Okay, the bottom radiator hose is cold. So I jacked the front up, squeezed the bottom hose many times and cannot get the air blockage cleared. Have done this a couple of times before with any problems. After 10 or so pumps and it clears. Anyone else have this problem? If so, what cleared it? Thanks


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