Overheated, Fan issue, Radiator

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ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Sun Aug 20, 2017 3:38 pm

ylbill wrote:Okay, the bottom radiator hose is cold. So I jacked the front up, heater on, 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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RRoller123
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Your car is a: 1980 FI SPIDER 2000
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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Sun Aug 20, 2017 6:53 pm

Hmmmm... radiator blockage?

Can you post a pic of the whole setup? use IMGUR.com

Use the fill plug at the union, not the radiator cap. Fill that (fill radiator through cap) first, then put the cap back on and jack up the car and use the fill plug to finish filling and bleeding it.

Pete
'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 7:43 pm

RRoller123 wrote:Hmmmm... radiator blockage?

Can you post a pic of the whole setup? use IMGUR.com

Use the fill plug at the union, not the radiator cap. Fill that (fill radiator through cap) first, then put the cap back on and jack up the car and use the fill plug to finish filling and bleeding it.

Pete

Hey Pete, I just added the Prestone flush T and topped it of there. I did a coolant flush and radiator seemed to drain pretty quickly through the fan switch hole, but not sure if that's a guarantee? Yesterday when I bled the system the bottom hose got warm, but not sure how hot. When you mentioned it might not be getting hot enough for the fan to come on I went to check today and its not even getting warm now. I'll try to get a pic.

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RRoller123
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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Mon Aug 21, 2017 7:15 am

Maybe your water pump has failed internally, or the belt is loose and it is not turning the vanes., or the T-Stat is stuck in the "cold" position (recirculates through block, little gets to radiator). There are only so many things that could be causing this.
'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 » Mon Aug 21, 2017 12:22 pm

RRoller123 wrote:Maybe your water pump has failed internally, or the belt is loose and it is not turning the vanes., or the T-Stat is stuck in the "cold" position (recirculates through block, little gets to radiator). There are only so many things that could be causing this.
I agree. Should be able to get to the root of the problem eventually. This forum is such a big help! Process of elimination I guess. Pretty sure the belt is good, but will verify belt and vanes are spinning. If good, probably go for the Tstat next? Thanks Pete!

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RRoller123
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Re: Overheated, Fan issue, Radiator

Postby RRoller123 » Mon Aug 21, 2017 5:49 pm

It is an odd problem you have, and the system just isn't that complicated. One of these things is going to reveal the answer shortly. :)
'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

vdesigner99
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Re: Overheated, Fan issue, Radiator

Postby vdesigner99 » Mon Aug 21, 2017 6:29 pm

I had a similar prob right after I replaced my original rad due to a broken weld. Once I replaced and burped as best as possible the dang car kept overheating. My visual besides the temp gauge was that the expansion bottle filled up fast with boiling anti-freeze and the lower hose wasn't hot. So out of curiosity I plugged the overflow tube from the rads to the plastic bottle. I did this since I noticed that the overflow hose was above the cap spring plunger. So with the hose plugged with vise grips the thermostat opened, the lower hose got hot and wallah the fan came on. And of course the temp dropped. So the conclusion, the rad cap that came with the radiator from VAS was either defective or was teh shorter version than my original. I replaced back with my original cap and haven't had probs since. I do have the pre-heater screw and cabin heater supply t-fitting.

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Victor
Last edited by vdesigner99 on Fri Aug 25, 2017 5:39 pm, edited 2 times in total.
1971 MGB Roadster (sold)
1977 fiat 124 (sold)
2010 Prius
2001 Sequoia
2006 20' REgal bowrider boat.
1984 Pinanfarina

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Mon Aug 21, 2017 6:57 pm

RRoller123 wrote:It is an odd problem you have, and the system just isn't that complicated. One of these things is going to reveal the answer shortly. :)
Agree and agree.

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Mon Aug 21, 2017 7:00 pm

vdesigner99 wrote:I had a similar prob right after I replaced my original rad due to a broken weld. Once I replaced and burped as best as possible the dang car kept overheating. My visual besides the temp gauge was that the expansion bottle filled up fast with boiling anti-freeze and the lower hose wasn't hot. So out of curiosity I plugged the overflow tube from the rads to the plastic bottle. I did this since I noticed that the overflow hose was above the cap spring plunger. So with the hose plugged with vise grips the thermostat opened, the lower hose got hot and wallah the fan came on. And of course the temp dropped. So the conclusion, the rad cap that came with the radiator from VATS was either defective or was teh shorter version than my original. I replaced back with my original cap and haven't had probs since. I do have the pre-heater screw and cabin heater supply t-fitting.

Image
Victor
Thanks for the post Victor. All these suggestions and similar issues give a direction to go in. Thanks

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kmead
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Re: Overheated, Fan issue, Radiator

Postby kmead » Tue Aug 22, 2017 7:17 am

A couple of things to keep in mind

Gauges are not accurate
Sensors are not accurate

The temp at the engine's sensor is going to be different than the actual temp in the radiator.
The fan switch is low in the radiator so it is already seeing partially cooled coolant so it is seeing a lower temp than the top hose

The thermostat opens at @190 or lower if a lower temp thermostat has been fitted

The fan switch is generally opening at or above 192, so the gauge is likely to show a higher temp than 192 before the fan will come on.

The steam may have been overflowed coolant and points to your radiator cap being faulty.

When you say the car overheated, what are the indications you are basing this on? If it boiled over and caused the coolant to boil out of the cap, likely the cap is bad as pointed out by others.

Don't expect the fan to come on at the same time that the gauge shows 190-200 degrees, it will likely come on in that upper region of that range. Lower temp switches are available and might be a good option for you, adding an over ride switch is another good option so you can turn the fan on manually when ever you want.

When you go back to bleed the system, raise the car at the front and try to have the side of the car that has the radiator cap an inch or so higher than the other side to make it the highest point in the system.
Karl

1969 Fiat 850 Sports Coupe
1970 Fiat 124 Sports Coupe
1985 Bertone X1/9

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Tue Aug 22, 2017 10:23 am

kmead wrote:A couple of things to keep in mind

Gauges are not accurate
Sensors are not accurate

The temp at the engine's sensor is going to be different than the actual temp in the radiator.
The fan switch is low in the radiator so it is already seeing partially cooled coolant so it is seeing a lower temp than the top hose

The thermostat opens at @190 or lower if a lower temp thermostat has been fitted

The fan switch is generally opening at or above 192, so the gauge is likely to show a higher temp than 192 before the fan will come on.

The steam may have been overflowed coolant and points to your radiator cap being faulty.

When you say the car overheated, what are the indications you are basing this on? If it boiled over and caused the coolant to boil out of the cap, likely the cap is bad as pointed out by others.

Don't expect the fan to come on at the same time that the gauge shows 190-200 degrees, it will likely come on in that upper region of that range. Lower temp switches are available and might be a good option for you, adding an over ride switch is another good option so you can turn the fan on manually when ever you want.

When you go back to bleed the system, raise the car at the front and try to have the side of the car that has the radiator cap an inch or so higher than the other side to make it the highest point in the system.
Lots of good information Karl. I think I'm going to order a radiator cap and then give it a shot again. Thanks

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Tue Aug 22, 2017 12:49 pm

ylbill wrote:
kmead wrote:A couple of things to keep in mind

Gauges are not accurate
Sensors are not accurate

The temp at the engine's sensor is going to be different than the actual temp in the radiator.
The fan switch is low in the radiator so it is already seeing partially cooled coolant so it is seeing a lower temp than the top hose

The thermostat opens at @190 or lower if a lower temp thermostat has been fitted

The fan switch is generally opening at or above 192, so the gauge is likely to show a higher temp than 192 before the fan will come on.

The steam may have been overflowed coolant and points to your radiator cap being faulty.

When you say the car overheated, what are the indications you are basing this on? If it boiled over and caused the coolant to boil out of the cap, likely the cap is bad as pointed out by others.

Don't expect the fan to come on at the same time that the gauge shows 190-200 degrees, it will likely come on in that upper region of that range. Lower temp switches are available and might be a good option for you, adding an over ride switch is another good option so you can turn the fan on manually when ever you want.

When you go back to bleed the system, raise the car at the front and try to have the side of the car that has the radiator cap an inch or so higher than the other side to make it the highest point in the system.
Lots of good information Karl. Yes, it did boil over. I think I'm going to order a radiator cap and then give it a shot again. Thanks

ylbill

Re: Overheated, Fan issue, Radiator

Postby ylbill » Tue Aug 22, 2017 1:30 pm

ylbill wrote:
ylbill wrote:
kmead wrote:A couple of things to keep in mind

Gauges are not accurate
Sensors are not accurate

The temp at the engine's sensor is going to be different than the actual temp in the radiator.
The fan switch is low in the radiator so it is already seeing partially cooled coolant so it is seeing a lower temp than the top hose

The thermostat opens at @190 or lower if a lower temp thermostat has been fitted

The fan switch is generally opening at or above 192, so the gauge is likely to show a higher temp than 192 before the fan will come on.

The steam may have been overflowed coolant and points to your radiator cap being faulty.

When you say the car overheated, what are the indications you are basing this on? If it boiled over and caused the coolant to boil out of the cap, likely the cap is bad as pointed out by others.

Don't expect the fan to come on at the same time that the gauge shows 190-200 degrees, it will likely come on in that upper region of that range. Lower temp switches are available and might be a good option for you, adding an over ride switch is another good option so you can turn the fan on manually when ever you want.

When you go back to bleed the system, raise the car at the front and try to have the side of the car that has the radiator cap an inch or so higher than the other side to make it the highest point in the system.
Lots of good information Karl. Well, no liquid on the ground, but heard some gurgling. I think I'm going to order a radiator cap and then give it a shot again. Thanks


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