I installed a Hayden High Performance 512 transmission cooler on my 2005 Civic automatic. Temp went from 180 to 120 when idling in drive for 10 minutes in 70 degree weather. My question is what is the ideal temp for transmission fluid? Is 120 degrees too cold? I live in big mountains and I would think it could use all the cooling it could get. Is 120 ok or too cold?
Overcooled transmission?
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I would take temp readings after driving for 1 hour in stop and go traffic and 1 hour of highway driving. 10 minutes is nowhere near operating temperature.
Originally Posted By: Avery4
I installed a Hayden High Performance 512 transmission cooler on my 2005 Civic automatic. Temp went from 180 to 120 when idling in drive for 10 minutes in 70 degree weather. My question is what is the ideal temp for transmission fluid? Is 120 degrees too cold? I live in big mountains and I would think it could use all the cooling it could get. Is 120 ok or too cold?
I am no mechanic but 120 sounds pretty cool to me, thats like taking a hot shower. If I am not mistaken some of the anti wear additives don't activate until a certain temp. The fluid will also be thicker than necessary at 120, I can not comment on whether or not that's a bad thing.
I installed a Hayden High Performance 512 transmission cooler on my 2005 Civic automatic. Temp went from 180 to 120 when idling in drive for 10 minutes in 70 degree weather. My question is what is the ideal temp for transmission fluid? Is 120 degrees too cold? I live in big mountains and I would think it could use all the cooling it could get. Is 120 ok or too cold?
I am no mechanic but 120 sounds pretty cool to me, thats like taking a hot shower. If I am not mistaken some of the anti wear additives don't activate until a certain temp. The fluid will also be thicker than necessary at 120, I can not comment on whether or not that's a bad thing.
The extra trany cooler on our car has a low temperature bypass so that the trany oil is not over cooled when it is too cold.
Moisture in the air condenses out of the air and into the transmission fluid, and contaminates the trany fluid with water. Water in the transmission fluid causes rust that can prevent moving parts from moving the way they should. I have an uncle that had the automatic trany in his mobile home go bad because there was enough water in his trany fluid to allow rust to form.
You want the trany fluid to get hot enough to cause moisture (water) to boil off. Don't underestimate the ability of water in the trany fluid to mess up an otherwise good transmission.
Moisture in the air condenses out of the air and into the transmission fluid, and contaminates the trany fluid with water. Water in the transmission fluid causes rust that can prevent moving parts from moving the way they should. I have an uncle that had the automatic trany in his mobile home go bad because there was enough water in his trany fluid to allow rust to form.
You want the trany fluid to get hot enough to cause moisture (water) to boil off. Don't underestimate the ability of water in the trany fluid to mess up an otherwise good transmission.
Assuming the fluid only flows when the car is in drive, perhaps drive it how I suggested and pull over somewhere and check the temperature ASAP? Immediately put it into park to keep it from cooling down.
You shouldn't have any moisture in your transmission whatsoever. Water is a byproduct of combustion.
You shouldn't have any moisture in your transmission whatsoever. Water is a byproduct of combustion.
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How does it run? You might want to write to Honda and ask them what the trans operating temperature range is.
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Near as I can tell, having water build up in your tranny is one of the risks. I think that's a pretty good answer.
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