Coolant temp gauge reading is lower after new head gasket

[92EcoDiesel Jetta]

The temp gauge used to read a little above the middle mark when I had a leaky head gasket. After installing a new head gasket, the temp gauge now reads quite a bit lower in all instances (idling, hwy). Is this normal? Did the combustion gas (which is much hotter than colant) leaking into the cooling system actually raised the coolant temp thus raising the temp gauge reading or do I still have air in the system?

[silentdub]

I assume you flushed the coolant during the job, maybe fresh coolant? New Thermo? Maybe you cleared away from crap from the sensor?

All play a factor, if you did flush it, maybe there was a blockage in the rad which is no longer there.

[RadoTD]

Did the combustion gas (which is much hotter than colant) leaking into the cooling system actually raised the coolant temp thus raising the temp gauge reading

Yes, if your head gasket was blown between the cylinder and water jacket, this would happen.

When all is well, these engines tend to run quite cool! Anything under 15*C if I'm actually moving, my thermostat doesn't open

[nathan_b]

Last winter I got my truck up to operating temperatures within 5 miles, I stopped and let it idle when itt was about 10f and it went all the way cold. haha

[R.O.R-2.0]

Last winter I got my truck up to operating temperatures within 5 miles, I stopped and let it idle when itt was about 10f and it went all the way cold. haha

i had my car almost over heating by the time i got to the top of the mountain i was going over, then i crested the peak, and oh boy, didnt take it long before the needle was buried clear back on the cold peg..

[92EcoDiesel Jetta]

Yes 2 flush with water only, no chemicals, same thermostat. I filled it with water and got the engine to operating temp (fans cycled= thermostat open) then pulled the hose off the thermostat housing and that drained the system in seconds. I let the engine cool overnight and repeated the procedure then filled with G12.

I assume you flushed the coolant during the job, maybe fresh coolant? New Thermo? Maybe you cleared away from crap from the sensor?

All play a factor, if you did flush it, maybe there was a blockage in the rad which is no longer there.