95 Accord EX: Temperature cools on downhill. Is this normal?

My friend has a 95 Accord EX 4 cylinder. After driving for a few miles
the temperature gauge goes to the normal position and doesn't move. It
stays there on flat roads and uphill. But when going downhill, like
the Grapevine in Southern California, the needle on the temperature
gauge will noticeably move to the cool end. I've never seen any other
car do this. The engine always runs fine regardless of this behavior.
Has anybody else noticed this on their Honda?

 

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Not normal... is the radiator full to the very top, and reservoir
half-full to the MAX line? This stuff is described in the owner's manual
if you don't know what I mean.

'Curly'

 

Perfectly normal.

Likely you are coasting downhill with foot TOTALLY off the gas. Honda's ECU
setup shuts off the fuel injectors till you get below 1100 rpm.

Therefore the cold air being sucked through the motor while coasting, cools
the engine along with the fact no combustion is taking place to CREATE heat.

 

I've never seen the Grapevine but if you're completely off the gas and
going downhill for an extended time, it wouldn't be impossible for the
engine temp to drop -- where would the heat come from to keep it up? -- but
not sure by how much. I know that if you idle for say 10mins with ambient
temps of ~15F, with the heater on middle temp and fan on 2nd notch, the
engine temp gauge will drop - not enough heat being generated by the idle
combustion. I'd check the thermostat to be sure it's closing - another
possibility is the temp gauge response: in most Hondas, the gauge has a
plateau in its response between 80C and 100C.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

That's Perfect normal. when I drive on downhill and my foot is not on
the gas, the temp gauge go down flat zero.

 

The temperature gauge of my 95 civic goes all the way down to a notch
above C when driving down a mountain with the heater at full blast.
This happens (even with a new thermostat) every winter weekend I go
snowboarding. The heater must be at full blast, blows lots of
lukewarm air though.

Just my 2 bits.
Bye,
Leon