Flashing Coolant Temp Light
08-25-2008, 01:49 PM
#1
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Flashing Coolant Temp Light
Maybe someone can shed light on the matter. I researched past threads in regards to flashing coolant temp light but they had different symptoms than the one I am experiencing.
I have an 85 CGT which starts and idles normally when cold. As soon as it reaches normal operating temp., it revs fine up until 2900 rpm. At around 3000 rpm, it starts to sputter and run like crap then the coolant temp light starts to flash. As soon as I take my foot off the gas and the rpm goes back to around 1000-1500, light stops flashing and idles normally. Any ideas?
I have an 85 CGT which starts and idles normally when cold. As soon as it reaches normal operating temp., it revs fine up until 2900 rpm. At around 3000 rpm, it starts to sputter and run like crap then the coolant temp light starts to flash. As soon as I take my foot off the gas and the rpm goes back to around 1000-1500, light stops flashing and idles normally. Any ideas?
08-25-2008, 08:41 PM
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Hmm, that's a stumper, at least as described.
First thing to do is obviously check the coolant level in the expansion tank. However, unless it's really low (which doesn't match up with the light not flashing at idle) I can't really see that being the problem.
It almost sounds like either a wiring problem or a head gasket problem.
Can you give any more information on this?
Tony
It almost sounds like either a wiring problem or a head gasket problem.
Can you give any more information on this?
Tony
08-25-2008, 10:06 PM
#4
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Its a faulty sensor....
My car did the same thing, as soon as it warmed up, the light would blink after taking a hard right or hitting a bump. Hopefully the new overflow tank will fix that.
08-25-2008, 10:45 PM
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Re: Hmm, that's a stumper, at least as described.
did head work with new hyd lifters, gasket and resurfaced. Cleaned out fuel distributor since there was gunk on the flap which made it stick and not move freely. ECU coolant sensor replaced. Coolant up to correct level. Like what I said, idles fine and revs great until 2900rpm. as soon as I pass the 3K mark, it sputters and light starts to flash as if it was a check engine light then goes away when the idle comes back down. Could it be that it has low fuel pressure? that's next on my checklist this weekend.
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08-26-2008, 03:38 AM
#8
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On the bottom of the plastic coolant tank...
I don't know if it can be replaced separately from the tank though. If yours is yellowed and cracking, its likely time to replace it anyway.
08-26-2008, 04:24 AM
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Sounds like a mixture or timing issue.
Have you double-checked both the valve timing and the ignition timing? If those are in sped, the next thing I'd do is find out which way the car goes, when over 3K. As in, rich or lean?
To do that, pull the airbox up slightly off the filter, I usually pull it out from under the core support and set the corner on top so it holds itself up. Then, start the car (make sure you didn't pull the intake boot off in the process). Go under the hood, and rev the car to the sputtering point. Then, put your hand in under the sensor plate and push up and pull down. See which way makes the car run better. If pulling down does it, you are running rich. In effect by pulling down you are leaning out the mixture. If by pushing up it runs better, you are too lean.
Let us know what you find.
Tony
To do that, pull the airbox up slightly off the filter, I usually pull it out from under the core support and set the corner on top so it holds itself up. Then, start the car (make sure you didn't pull the intake boot off in the process). Go under the hood, and rev the car to the sputtering point. Then, put your hand in under the sensor plate and push up and pull down. See which way makes the car run better. If pulling down does it, you are running rich. In effect by pulling down you are leaning out the mixture. If by pushing up it runs better, you are too lean.
Let us know what you find.
Tony
