I have a 2007 Chevy Silverado w/ 4.8 4l60e w/ 84k miles and it is overheating sitting at idle or stopped in traffic however as soon as I start moving it will cool down. I tried my rad/coolant reservoir cap and still not better. Where should I start looking?
Odd overheating issue
- Thread starter brandontyler65
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I would look at the cooing fan. poor operation will cause overheating at stops, when moving the fan isnt needed.
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OVERKILL
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Sounds like a failure of the fan clutch.
ditto - fan(s), check them for proper operation, also for obstructed radiator.
Electric Fans and they turn on when the engine is running hot and no obstructions also I have no external trans cooler only the one in the rad but this was never a problem before in warmer temps the gauge always showed 210 and never moved.
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Overheating when standing still almost always implies an airflow problem. Check the cooling fan(s) and especially the viscous fan clutch if its an engine-driven fan. That would be my number one suspect.
If you have electric fans, find out if they're 2-speed fans and if the low speed is working. I've had one vehicle where the low fan speed failed and so the fans wouldn't even come on until the temp was well above normal.
Finally.... are you sure its REALLY overheating? Dash gauges and sending units can fail causing incorrect readings.
If you have electric fans, find out if they're 2-speed fans and if the low speed is working. I've had one vehicle where the low fan speed failed and so the fans wouldn't even come on until the temp was well above normal.
Finally.... are you sure its REALLY overheating? Dash gauges and sending units can fail causing incorrect readings.
well the fans are coming on and they seem like they are running low speed when this happens but no high speed, however, when I turn on the A/C both fans go from low speed to high speed. I have looked and there is no obstructions at all. I would suspect the gauge is correct as it has a very hot coolant smell around the truck when it is in the state. I have one question as I have considered the thermostat and I will probably replace it but I want to know if there is only one temp sending unit on my engine that sends signal to both my gauge and the fans (the one on the driver's side cyl head) as those are cheap to replace and I will while I am changing the thermostat if that is the one.
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
This problem is simple -- for some reason the electric rad fans are not turning on when the engine is idling. Check more or less in this order, fuses, relays, solenoids, fan thermostat/switch and finally that the fans will run when receiving current.
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
This problem is simple -- for some reason the electric rad fans are not turning on when the engine is idling. Check more or less in this order, fuses, relays, solenoids, fan thermostat/switch and finally that the fans will run when receiving current.
Originally Posted By: TomYoung
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
This problem is simple -- for some reason the electric rad fans are not turning on when the engine is idling. Check more or less in this order, fuses, relays, solenoids, fan thermostat/switch and finally that the fans will run when receiving current.
He's already mentiond it has electric fans.
However, your assumption that vehicles today don't have engine-driven fans is false. Many trucks today still use engine-driven fans.
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
This problem is simple -- for some reason the electric rad fans are not turning on when the engine is idling. Check more or less in this order, fuses, relays, solenoids, fan thermostat/switch and finally that the fans will run when receiving current.
He's already mentiond it has electric fans.
However, your assumption that vehicles today don't have engine-driven fans is false. Many trucks today still use engine-driven fans.
OVERKILL
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Originally Posted By: TomYoung
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
This problem is simple -- for some reason the electric rad fans are not turning on when the engine is idling. Check more or less in this order, fuses, relays, solenoids, fan thermostat/switch and finally that the fans will run when receiving current.
My M5 has an engine driven fan and so does my Expedition. Neither are from 1975 sir. You'd be surprised at the number of vehicles that have retained this setup through the last decade.
Quick Google:
2009-2010 Ford F-150 Fan Clutch - Motorcraft - Standard thermal
The OP later clarified that it was electric, however I don't think there is anything wrong with me assuming it MIGHT be mechanical.
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
This problem is simple -- for some reason the electric rad fans are not turning on when the engine is idling. Check more or less in this order, fuses, relays, solenoids, fan thermostat/switch and finally that the fans will run when receiving current.
My M5 has an engine driven fan and so does my Expedition. Neither are from 1975 sir. You'd be surprised at the number of vehicles that have retained this setup through the last decade.
Quick Google:
2009-2010 Ford F-150 Fan Clutch - Motorcraft - Standard thermal
The OP later clarified that it was electric, however I don't think there is anything wrong with me assuming it MIGHT be mechanical.
Tyler,
I would add an external transmission cooler as the tranny may be adding too much heat at idle. I would also change the fluids since they are about five years old if not already serviced.
I would add an external transmission cooler as the tranny may be adding too much heat at idle. I would also change the fluids since they are about five years old if not already serviced.
With a fan clutch, isn't the fan supposed to be turning whenever the engine is at idle ?
Faulty fan system or coolant sensor for it.
Also, a bad WP impeller [corroded or loose] can cause tough to determine problems.
Also, a bad WP impeller [corroded or loose] can cause tough to determine problems.
Originally Posted By: TomYoung
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
MANY trucks still have engine-driven fans, especially heavier duty trucks. They may also have electrics, either as boosters for the engine-driven fan or like my Ram 1500 where the radiator, trans cooler, and PS oil cooler are served by the engine-driven fan and the AC condensor has its own electric fan and isn't in-line with the radiator at all.
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
Maybe in 1975 it sounds like that. I would be shocked if this vehicle has an engine-driven fan.
MANY trucks still have engine-driven fans, especially heavier duty trucks. They may also have electrics, either as boosters for the engine-driven fan or like my Ram 1500 where the radiator, trans cooler, and PS oil cooler are served by the engine-driven fan and the AC condensor has its own electric fan and isn't in-line with the radiator at all.
OVERKILL
$100 Site Donor 2021
Originally Posted By: Merkava_4
With a fan clutch, isn't the fan supposed to be turning whenever the engine is at idle ?
The fan turns all the time, but it is only "directly coupled" to the engine when the clutch locks. This is temperature dependent.
With a fan clutch, isn't the fan supposed to be turning whenever the engine is at idle ?
The fan turns all the time, but it is only "directly coupled" to the engine when the clutch locks. This is temperature dependent.
Originally Posted By: mechtech2
Also, a bad WP impeller [corroded or loose] can cause tough to determine problems.
This. Next time it happens, crank the heat. If the water pump is working right it should be scalding hot. If it's tepid, you have water flow issues.
Also, a bad WP impeller [corroded or loose] can cause tough to determine problems.
This. Next time it happens, crank the heat. If the water pump is working right it should be scalding hot. If it's tepid, you have water flow issues.
Originally Posted By: OVERK1LL
Sounds like a failure of the fan clutch.
+1
Sounds like a failure of the fan clutch.
+1
http://www.ls1tech.com/forums/general-ma...obably-why.html
That sounds very much like an air flow issue; do you drive in extremely dusty conditions or areas with lots of bugs? They can clog up the front of the radiator over time and severely block airflow during low speed driving, even if the fans are running.
That sounds very much like an air flow issue; do you drive in extremely dusty conditions or areas with lots of bugs? They can clog up the front of the radiator over time and severely block airflow during low speed driving, even if the fans are running.
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