2013 with the N18 motor.

I changed my thermostat earlier this year. It was good for several months, now I'm getting intermittent cold running - Lately, more often than not. Also - the cooling fan seems to run to much - as in the engine temperature might be 165°F, but the fan keeps running after the motor is off. I suspect the fan is running while the car is warming up.

Can anyone give some insight in the fan operation? I have been assuming that the fans are triggered by the same coolant temp I'm seeing on the scan tool - is that correct?

Is there any test for the electrically controlled thermostat?

Thanks guys!

 

Bleed the system and get the air pockets out.......of the system ......

 

That's interesting - I did go to quite a bit of trouble to bleed the air when I installed the thermostat last winter. All was great until recently - I will bleed air again.

Thanks

 

You definitely need to make sure all the air pockets are purged from the system.......

 

Got home from work, put it in the garage and popped the hood. Coolant is at 120°F, fan behind the radiator is running full blast with the engine running.

I cracked the bleeder on the thermostat housing and only got liquid. Jacked the front end up with the car still running - only liquid from the bleeder.

Fan is still running several minutes after the car is off.

 

Looking at some related threads here on the site (and looking for tricks regarding bleeding the coolant) - I'm suspecting the wiring for the temperature sensor. My new thermostat is a different arrangement than the original and it needed a harness to adapt - I'm suspicious that I have an electrical issue - especially with the fan running constantly.

 

did you mix up the plugs from the thermostat? There is another plug on that same harness that will fit in the thermostat that would throw everything off. If memory serves, the thermostat should be the green plug.

 

I did check connections - the "adaptor" harness that comes with the new style thermostat is pretty cheesy. Having said that - when I monitor coolant temps, they seem to match up well to reality. I pulled the relay for the rear fan, which got things a bit warmer, but driving in cold temps brought them right back down. I bought a new thermostat - All I can figure is that the "new" one is bad already.

BTW - I probably need to Join the Chili Red owners club.

Thanks!

 

So it got very cold here and I was able to spot a coolant leak at the water pump. I couldn't tell if it was the pump gasket or the cross tube, so I bought both. I replaced the thermostat, cross tube and water pump.
On the removed cross tube the o-ring at the back of the water pump was "rolled" - so I think that was the cause of the leak. Interesting that it didn't seem to drip until very cold weather (Like 0°F), but was apparently letting air in. I wasn't needing to top up coolant.
I checked the two electrical connections on the new thermostat and the one I replaced - they both showed the same resistance values. The "plunger" on each thermostat had about the same gap from the seat outside the car - which seems weird to me - I expect a thermostat to be closed in ambient conditions.
After everything was buttoned up the cooling system purged more easily than I can ever recall. There's no more excessive fan running - so I think the thermostat was fine, air in the system was causing the symptoms.
I will say the car still doesn't get as hot as it did before I replaced the original thermostat (with the temperature sender in a separate housing). Now the car rarely reaches 160°F unless I run it hard - then it gets up to 195° or so. I'm used to modern cars operating @ 200° - 220°.