andyra

2002 Civic 1.7L Over heating problem
386,000km.
Engine replacement at 248,000km with an engine with 60,000km on it

Past History:
Has a used engine installed with 60k on it June 2017
Drove it once, and all was fine. Heat and all
2nd time i drove it, it started to overheat within 10 minutes
Towed back to mechanic, who removed temp sensor to help eliminate air.
Topped up coolant.
All was good for the last 15+ months

Three days ago, I got an oil change.
They tested the coolant, which they said was acidic. So I said ok to a change, as this could cause head gasket issues
They flushed the cooling system with a flushing machine
All seemed good
The next morning to work, noticed NO HEAT inside the cab, even though the temp gauge was at normal location
After about 20 minutes of driving (most hwy), the temp jumped to HOT.
Managed to get off hwy and to a garage quickly. I suspected air in the system
They eventually replaced the thermostat, which had some rubber damage. Was probably stuck
Was able to drive car to work, WITH HEAT in my car. Drove another 30 minutes

Drive home after work
After about 15 minutes, turned on the heater, only to notice NO HEAT again.
Also noticed temp gauge was at MAX again, over heating
Was able to get to gas station quickly.
Topped up coolant (once cooled a bit), but still experienced over heating
** Always ran HEATER AT FULL, while working with the cooling system.
Had 2002 civic towed home

Today, noticed the that the rad cap leaked, when under pressure - replaced
Did a combustion test at the radiator. No evidence of combustion gas (a head gasket leak.)
removed the temp sensor from the top of the casing, and noticed there was no or very little coolant at top of engine. I was expecting some air pocket, but not that empty.
Ran car with temp sensor out, but still never saw coolant level come up through the sensor hole.

I'm a bit stumped.
Could the mechanic have put the new thermostat in upside down? (hole should be at top)? May check for this.
Again, all was working fine before the flush 2 days ago.
Any suggestions welcome. Family want me to part with the car, but I'm still getting over 40mpg. I don't want to give up yet. But I'm not prepared to put much money into it.

Thanks

GolNat

iTrader: (7)

Wankenstein

A block test only detects emissions gases in coolant but not all head gasket breaches allow emission gases in. The best test for head gasket breach is a cylinder leak down test with staright 125-150 psi shop air pushed into the cylinders via spark plug holes one at a time at TDC.

For proper coolant air bleeding:
Raise front of car as high as possible on jackstands (radiator neck higher than engine)
Set the climate control to max heat with fan off
Bleed air and replace coolant as needed in radiator and reservoir until coolant fan engages twice. I prefer to rev the engine for 30 seconds occassionally during the bleed to help force air out of the system but finish off for at least few minutes at idle only to ensure zero (or near to/very tiny) bubbles.
Turn off engine, remove jacks and allow engine to fully cool before checking radiator and reservoir levels

Other than that possibly a weak/failing waterpump (but rare on these engines) or headgasket issue.