Got my new head installed, everything back together with new water pump, timing belt, etc. Had to solder new capacitors on the ECU to get the code 15 to go away.

https://www.hondaaccordforum.com/for...68/#post402932

Drove it to work this morning for the first time, and the ONLY things that need to be addressed are a noisy P/S pump (will probably just replace with a used one from ebay, and my engine fan doesn't come on. If I turn the AC on, both fans come on, but with the AC off, the temp gauge will climb up a little over the middle of the gauge and neither fan comes on. Is that supposed to come on based on the engine temp sensor on the passenger side front of the head? I broke that sensor removing the head, and had to order a replacement and I'm wondering if I got a bad sensor.

 

The switch on the front of the head with a green connector turns on the fan when the engine is not running to prevent heat soak. The switch you need to inspect has a green connector near or on the thermostat housing. That switches the fan on at a set temp when the engine is running. If you need to replace the sensor, make sure you get the correct sensor as those two sensors turn on at different temps. IIRC, 199F when engine is running and 210F when engine is off to stop heat soaking.

You can unplug the temp switch on the thermostat housing, start the engine, then short the two pins on the electrical connector. If both fans turn on, then you likely have a bad temp switch.

 

Thanks @PAhonda . I need to delve back into this.

I've got about 1500 miles on it now after the head replacement. Runs great up and down the highway, and I've just been running with the AC on so the fans are running. I've noticed now that it's warmed up a little bit that the temp gauge climbs up a bit higher than it's usual set spot. Also seems like the car warms up a little quicker than it used to. Maybe a partially stuck thermostat? Also noticed the idle goes up once the car is fully warmed up. I know air in the system can cause this but I've bleed the coolant with the bleeder a half dozen times with no change.

I have a 30 min commute to work every day, all highway. Crank car in the morning and everything works normally. Idle is an 1100ish for a min, drops to 600-700 by the time I get to the first stop sign. Drop kid at school, everything operates as it always has. Get to work a half hour away and idle will usually be up around 1100-1300. Shut car off and let it sit for 7-8 hours. On the way home, the temp gauge will move up just a hair over the normal spot, but still not reaching the half way point. Idle will be high again much sooner than on the cold start in the morning.

I'll check that coolant temp sensor.

Anything else I should be looking at? I don't know much about the ECU's but I did solder on all new capacitors on the ECU when I was ready to put it back on the road. I was getting a start/immediately die situation at first and an error code that pointed to a bad ECU. I inspected capacitors and some had leaked so i replaced and the code went away and it's started/run fine since. I don't supposed any of those capacitors have anything to do with the cooling/fan system do they?

 

Jumped the connector on the thermostat housing and both fans immediately came on, so guessing that temp sensor is bad if the fans aren't running when the temp gauge gets a little higher than it's usual spot?

 

Well my hypothesis is, that plug on that temp sensor wasn't making a good connection. Since I unplugged it to test the fans, and plugged it back in, the temp gauge has remained steady and the idle being all over the place has settled down to normal idle for the most part. It still idles at 1K-1100 every once and awhile but for the most part it's under 1K, whereas before it would surge up to 1300-1400 RPM at idle once warmed up.