Hello all, I did post a thread very similar to this one, I think there was a loss in what else I was inquiring about. So please read the full detail of this, as there is more then 1 question?

I have a 1991 Civic SI, Manual, 1.6L stock motor, 256k+ miles, 1 top end rebuild and a few bolt on's,

I just recently replaced the rusted out muffler, the radiator exploded on me so I replaced it, the thermostat and the ECU temp sensor, ( the water temp sensor would read cold no matter how long I drove the car for, that's why I thought I replaced it) the part I got from AutoZone had 2 wires,< I found the Coolant temp sensor for the gauge about an inch and half up to the left of the ECU sensor, that's get replaced tomorrow)

The gauge cant decide where to sit its either hot or cold and when I give it throttle it levels out once I let off the gas it bounces around, and then settles on hot or cold, (which is odd now that I know that the Green/Yellow wire for the temp gauge is just resting on the block) it appears to be holding water, I don't see any visible leaks, the upper and lower tubes get hot so I believe the pump is working.

The other odd thing is the exhaust, so during the radiator replacement I had the car jacked up to burb the system, and I noticed that what looked like water pouring, no Cascading out of the exhaust, no smoke at idle! After burping the radiator, I took it for a drive for about an hour, it started to kick out white smoke for a little while but once I think the exhaust got hot enough it quit smoking! It seemed to run fine, but the temp sensor still bouncing around. with the temp sensor going ape ****, I hard wired the fans to a switch to ensure nothing over heats

***Now I know that usually white smoke that smell like burnt sugar is usually a busted head gasket or cracked block, however the white smoke just smells like exhaust, and no its not blueish smoke either and the oil doesn't feel or look like it has water in it. I also know that these symptoms are usually complemented, with other complications, that I have not experienced. no chug, no loss of power, and the white smoke stops after driving for a while.*** The confusing part?

To help with your help, I live in an area where the Temp is 85 degrees F year round, and about 90-110% humidity, most of the time. occasional will drop to 74f (so cold,... LOL)

I'm at a loss I've never came across this before. Any help is greatly appreciated..

 

Hello again, update for yawl,

So I replaced the temp gauge sensor, the gauge seems to be working now, and the motor is not over heating, I drove it for about a half hour in the 85f degree heat, some stop and go traffic I rallied on it a little, zero loss of power, no chugging, seems to run fantastic, however I noticed at the end of the drive it was kicking out white smoke, I checked the oil before I started and it doesn't appear to have water in it, and I'm not getting any signs of water loss in the radiator.

If any one has an idea of what this could be please let me know?

 

its really hard to tell you what the problem is without being there in person
but from what i read
one thing that comes to mind is a pcv valve thats not working right anymore

remove it
blow into it with your mouth
its a one way valve so air can only pass threw one way

if you cant blow air threw it freely
then this may be your problem

 

Thanks for the tip, I just replaced the PCV and it does run better, although there is another strange thing happening, so first thing in the morning it starts and runs great, I drive all around town making stops and driving more and more, then if I let it sit for an hour or so, then start it up it act like it not getting fuel or air, and wont idle but if I rev it, it smooths out and goes back to running great? any ideas?