Rebuilt the d15b7 head, resurfaced the whole nine. The car's h2o temp sits 1/2 in the gauge. I bypassed the fan switch using a paper, clip and the fan comes on. Bleed the air out of the system and still does the same, sits at 1/2 way on the h2o gauge.

I'm thinking maybe the thermo sensor that located in the housing is bad, what test can i do to confirm it's bad and move on to the next step of troubleshooting?

Cylinder Pressure is super

190
185
185
180

for a bottom end that has almost 200k on it.

 

So it's not overheating?

 

it has not yet, but i think where the needle in the gauge is sitting is a little too high. don't you agree? also the fan hasn't kicked on which concerns me a lot. i don't want to be sending the head back for milling if it overheats again...

just be proactive and trying to fix all my concerns as well.

 

Bone stock D15b7?

If you leave the fan switch jumped so the fan runs all the time and then drive and idle the car, does the temp gauge stay below 1/2?

 

I didn't want to go that route with fan switch / connector jumped. This isn't how it should run... But I will try this method to see where the temps are. This is the only way to get the fan to come on so far.

Im going to pull the thermo sensor and see if there is any kind of crud built up on it...

 

It did not mean for the jump to be permanent. It's just a test to see if the temp gauge needle drops to normal.

 

What do you guys think is a normal reading? I've always been running about 2-3mm below the 1/2 mark.

 

Both my Civics read like this^. And this seems to be true of most of our Civics. In my opinion, the engine is overheating if the needle points to the halfway mark.

 

I will be investigating the thermostat in tomorrow after work. Just rode around the neighborhood to test the fan always on method, and still stays at 1/2.

Next thing to test the thermostat and pressure test radiator.

 

Checking the thermostat is worthwhile, but it's curious that the fan switch does not activate with the needle at the halfway mark. Either the fan switch doesn't work or the temp gauge reading is off.

 

^ I would suspect that....


My 98 sit's about half way on the guage and has always been that way.

 

Thanks guys for the help more investigating to come. I can always trying another cluster

 

burned a chip with crome to do some datalogging, temp is 176F which is in the safe zone, not done any hard runs yet... more to come...

 

Make sure your heater hoses aren't backwards. I tend to put a new oem thermostat in. I don't trust anything else.

 

Final test drove to L.A and got stuck in major traffic, didn't overheat at all. Gauge sensor maybe broken or the gauge it's self.