Engine Fan Stuck On High
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
Likes: 61
From: Foster City Ca.
Engine Fan Stuck On High
Brought my 2026 Stingray home from the dealer yesterday, the ride home was smooth and uneventful. Got in it this morning to take it out for a shakedown cruise, and the engine fan came on high speed immediately, and won't shut down. I noticed that the coolant temp gauge has no reading.
I pulled it in the garage, just about to disconnect the battery, and the fan finally shut off. I'm guessing about ten minutes had lapsed.
Holiday weekend, no service available for 4 days :-(
Anyone else experience this?
I pulled it in the garage, just about to disconnect the battery, and the fan finally shut off. I'm guessing about ten minutes had lapsed.
Holiday weekend, no service available for 4 days :-(
Anyone else experience this?
Melting Slicks
Joined: Jun 2004
Posts: 3,496
Likes: 700
From: panama city beach florida USA
St. Jude Donor '09
Brought my 2026 Stingray home from the dealer yesterday, the ride home was smooth and uneventful. Got in it this morning to take it out for a shakedown cruise, and the engine fan came on high speed immediately, and won't shut down. I noticed that the coolant temp gauge has no reading.
I pulled it in the garage, just about to disconnect the battery, and the fan finally shut off. I'm guessing about ten minutes had lapsed.
Holiday weekend, no service available for 4 days :-(
Anyone else experience this?
I pulled it in the garage, just about to disconnect the battery, and the fan finally shut off. I'm guessing about ten minutes had lapsed.
Holiday weekend, no service available for 4 days :-(
Anyone else experience this?
Race Director
Joined: Mar 2007
Posts: 11,249
Likes: 8,384
I was speculating that a failure of a sensor might cause the fan(s) to default to on. The diagnostics for each DTC will include actions taken when the DTC is set, and its possible that one of the actions is to turn on the fan. I tried to search the 7000 page manual for that, but without a code its hard for me to search for it. My understanding from the manual is that the engine compartment fans are normally controlled by the engine compartment temperature sensor. So, that's not the source of the coolant temperature we see on the DIC. But its still possible for a coolant temperature sensor issue to trigger a fan action - I just do not know.
I agree the absence of a coolant temperature reading is a clue that its either a sensor problem, or an actual issue with coolant or coolant temperature.
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
Likes: 61
From: Foster City Ca.
Some DTCs don't set a CEL. However, I would expect a DTC related to a cooling system issue to either set the CEL or cause a DIC message. The manual mentions that message "may" appear on the DIC if there is an overheat condition.
I was speculating that a failure of a sensor might cause the fan(s) to default to on. The diagnostics for each DTC will include actions taken when the DTC is set, and its possible that one of the actions is to turn on the fan. I tried to search the 7000 page manual for that, but without a code its hard for me to search for it. My understanding from the manual is that the engine compartment fans are normally controlled by the engine compartment temperature sensor. So, that's not the source of the coolant temperature we see on the DIC. But its still possible for a coolant temperature sensor issue to trigger a fan action - I just do not know.
I agree the absence of a coolant temperature reading is a clue that its either a sensor problem, or an actual issue with coolant or coolant temperature.
I was speculating that a failure of a sensor might cause the fan(s) to default to on. The diagnostics for each DTC will include actions taken when the DTC is set, and its possible that one of the actions is to turn on the fan. I tried to search the 7000 page manual for that, but without a code its hard for me to search for it. My understanding from the manual is that the engine compartment fans are normally controlled by the engine compartment temperature sensor. So, that's not the source of the coolant temperature we see on the DIC. But its still possible for a coolant temperature sensor issue to trigger a fan action - I just do not know.
I agree the absence of a coolant temperature reading is a clue that its either a sensor problem, or an actual issue with coolant or coolant temperature.
Melting Slicks
Joined: Jun 2004
Posts: 3,496
Likes: 700
From: panama city beach florida USA
St. Jude Donor '09
Thank you for your thoughts, I'm also surprised that there was no CEL warning issued. I'm assuming that there was some kind of DTC, because when the dealer started the car up in the morning to bring it around to deliver it to me, they noticed the problem and had someone in their service department look at it. They told me that there was no CEL and no other issue was found, so they just reset it. From there it operated normally on my trip home, but when I started it the next day, the runaway fan problem was back, and I that's when I noticed that the temperature gauge was either not operating or reading zero. All other readings were normal. The fan runs at a super fast speed, I can hear it running when I'm in the house and the car is in the garage. I don't actually think that it's overheating, since it begins the instant that the engine is started, it hasn't had time to overheat, or even reach normal operating temperature. I'm taking it in to the service department on Monday to see what's up, in the meantime, I have a brand new Corvette sitting in my garage.
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
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From: Foster City Ca.
Well, I'm not taking it back to the same dealership. MacMulkin courtesy delivered it to that dealer who delivered it to me broken. There is another dealership only 4 miles away, I'll be taking it there to have the problem diagnosed and corrected. I won't really need a loaner, the Corvette isn't my daily driver...unless they want to offer me another C8. I'm really hoping that they won't have to disassemble it too far to replace the coolant temperature sensor.
Race Director
Joined: Mar 2007
Posts: 11,249
Likes: 8,384
Thank you for your thoughts, I'm also surprised that there was no CEL warning issued. I'm assuming that there was some kind of DTC, because when the dealer started the car up in the morning to bring it around to deliver it to me, they noticed the problem and had someone in their service department look at it. They told me that there was no CEL and no other issue was found, so they just reset it. From there it operated normally on my trip home, but when I started it the next day, the runaway fan problem was back, and I that's when I noticed that the temperature gauge was either not operating or reading zero. All other readings were normal. The fan runs at a super fast speed, I can hear it running when I'm in the house and the car is in the garage. I don't actually think that it's overheating, since it begins the instant that the engine is started, it hasn't had time to overheat, or even reach normal operating temperature. I'm taking it in to the service department on Monday to see what's up, in the meantime, I have a brand new Corvette sitting in my garage.
Racer
Joined: Feb 2020
Posts: 387
Likes: 576
From: Philly
Similar issue back on my 6th Gen Camaro. Turned out that the thermostat was stuck open, if the operating temperature doesn't come up in a certain amount of time it triggers the high speed fan.
Hope whatever it is, is an easy fix.
Hope whatever it is, is an easy fix.
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Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
Likes: 61
From: Foster City Ca.
Thanks, I considered that, but since it happens instantly and not after a certain period of time, I disregarded that, and went back to the faulty sensor theory :-)
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
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From: Foster City Ca.
Thanks Jim, I'm hoping that the sensor is easily accessible and they won't have to keep it long. I kind of know what the sensor looks like, but could not locate it in my Stingray, which makes me worry.
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
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From: Foster City Ca.
Good to know, many thanks. I'll ask if I can wait for it when I take it in on Monday. It sucks to have only 40 miles on it and have it just sitting in my garage :-(
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
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From: Foster City Ca.
I took it in today and was told that it would be two days to get a complete and accurate diagnosis. I was also told that if it turns out to be the coolant temperature sensor, some serious labor time would be involved. The car has 40 miles on it :-(
Pro
Joined: May 2025
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From: Huntsville
Seems like an odd statement to make. Especially if it’s under warranty. Start the lemon law time tracker!
Race Director
Joined: Mar 2007
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For the Stingray, there are up to three coolant temperature sensors. One is the block sensor - which I think - 99% sure - is the one that is displayed on the DIC. The other two I think are associated with the rear, right side radiator if you have Z51, and rear left side radiator if you have V09 (which we don't have in the US). So, if your issue turns out to be the block sensor, replacing it require removal of the engine, and the oil tank. The one page procedure looks real simple - just remove and replace the sensor. But unfortunately it includes a call to procedure to replace the oil tank. And the first step in that procedure is to remove the engine. So yeah its labor intensive.
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
Likes: 61
From: Foster City Ca.
For the Stingray, there are up to three coolant temperature sensors. One is the block sensor - which I think - 99% sure - is the one that is displayed on the DIC. The other two I think are associated with the rear, right side radiator if you have Z51, and rear left side radiator if you have V09 (which we don't have in the US). So, if your issue turns out to be the block sensor, replacing it require removal of the engine, and the oil tank. The one page procedure looks real simple - just remove and replace the sensor. But unfortunately it includes a call to procedure to replace the oil tank. And the first step in that procedure is to remove the engine. So yeah its labor intensive.
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
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From: Foster City Ca.
Race Director
Joined: Mar 2007
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The work wont take that long, but they have to obtain the parts. Probably more parts involved since they remove the engine and oil tank. I did not check that.
If that is even the problem.....
Thread Starter
Instructor
Joined: Aug 2014
Posts: 152
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From: Foster City Ca.
I don't think I would. But I think what he is talking about is simply the length of time they have it in the shop. If its over 30 days beyond the first day (think something like that) then it qualifies for lemon law if you find that you want.need to go that route. You also get (woohoo) 1 day of extension of the factory warranties for each day beyond the first day that it is in the shop. Thats stated in the Warranty Manual.
The work wont take that long, but they have to obtain the parts. Probably more parts involved since they remove the engine and oil tank. I did not check that.
If that is even the problem.....
The work wont take that long, but they have to obtain the parts. Probably more parts involved since they remove the engine and oil tank. I did not check that.
If that is even the problem.....