Rough Idle (cold) & Poor gas mileage

[momerath71]

The coolant smell is diminished but still there--guess I'll leave the thermostat alone so as not to pressurized any weak spots. The roughness on startup is gone, though, as well as the CEL. Two out of three isn't bad!

 

[alohamonte]

test

with the engine cold, take off the radiator cap. then start up the engine and watch for 5 minutes to see if the water circulates. if it does, then you're fine.

i did this test when i notice a small drip/leak in the heater control valve. that was the weak spot in my system which i'm happy about. better a $14 part leak then cracking the block...

i changed out the tstat, heater control valve, rad cap, and flushed the coolant system. works great now.

you might want to do a little seafoam treatment while you're doing your tuneup.