'93 Civic Cdn CX with an original computer (P08) and a non-original
engine (D16Z6 - the D15 engine died a while ago) with a new radiator
(installed with the Z6 engine a little over a year ago) - this problem
showed up only in the past month.
Engine comes up to just-below-midpoint temperature reading normally.
After long drives (i.e. engine warmed up) when left idling (red
traffic light, stuck in traffic, etc) temperature reading starts
climbing. I've seen it go almost to the red line. If the engine RPMs
are brought up the temperature will come back to normal - either
through normal driving, or by putting the car in neutral (with brakes
on, of course) and gently touching the gas.
Any sort of engine load (RPMs up) and the temperature regulates
Coolant level looks OK - there's fluid in the overflow tank and the
inside rubber hose is 'wet'. Color is green, looks clear.
When the engine is warm, the 'low idle' seems to be quite low -
sometimes the engine seems to want to stall. I wonder if this very low
idle mode isn't conducive to proper coolant flow. Any other theories?
Water pump, maybe?
Second question: my mechanic is fairly insistent that older Honda
engines (> 200000 km) tend to start consuming oil, and that this isn't
a big concern. Agree/disagree, anyone?
I'm about 1500 km into an oil change and noticed that the dipstick
level has come down from 'full' to halfway between the dots. I also
see some oil under the engine on the driver's side where the plastic
of the bumper comes in under the engine compartment, so I suspect a
slow leak more than actual oil burning (tailpipe doesn't show any
signs of oil burning).