I have a 1998 Honda CR-V. The transmission went bad. I ended up rebuilding the Transmission and engine while I had it out. I have no experience in this. I watched many YOU TUBE videos to learn how to do it. The engine is a B20B with a auto AWD transmission. Nothing fancy all stock. New parts related to coolant: water pump, thermostat*, radiator, replaced drivers side fan motor**, new coolant sensor on thermostat housing. *I took the thermostat out to make sure the new one was not the problem and have not reinstalled it yet. **after driving the car, the temp was very hot but not to the red I had the A/C on both fans were running, I cut the A/C off and both fans cut off with the engine very hot. Seems odd but when the engine got hot I had the A/c on. Another thought was a bad head gasket. I got one of those head gasket testers that you pour the blue liquid into and see if it turns yellow. It never turned yellow. According to that test the head gasket is good. I have a tester to check for the proper coolant ratio and I have the correct ratio. I was also concerned about an air bubble in the system, I took off the upper radiator hose and hooked a water hose to it and let the water run thru it for a few mins. One other thing that may be related is that if I drive the car and it gets hotter than it is suppose to (not to the red line), and I cut it off to let it cool down it has a hard time starting back up. It turns over slowly and gradually speeds up until it starts. It may take about 2 mins to start. If the car has sat overnight It starts perfectly.
At this point I do not know what to check. Any help would be appreciated. I work full time and am doing all off this after my job and have spent the last several months working on the rebuilds.

 

welcome to the forum. have you flushed out the radiator, after overhauling and engine, there may have been a lot of debri in the water system.. or you can reverse flush the rad system by getting a water hose hooded up to the bottom radiator and a air pressure line, run the water until it come out the top hose ( disconnected aimed down) and blow the air pressure at the bottom and watch all the debri come through. or send it out to a shop and have them overhaul the rad.

 

I will try that tomorrow afternoon. I did disconnect the top hose and hook a water hose to it (no air hose) and run the water thru the entire system until it came out of the top of the radiator. But I can see how what you said would be more directed towards the radiator. I will try that and see if I get results. Thanks

 

i used a rag and wrapped a figure eight around the water hose and air pressured line and stuffed it into the lower rad hose, then after the water started running out the top hose, i would depress the air nozzle and let the air/water blow out the junk on the top of the radiator core. if you have a cotton bag or nylon to loosely wrap the top hose you might see how much junk/corrosion comes out. if minimal, you may have another problem to cause the overheating. is the timing set at factory spec's, retarded timing will cause overheating, to advanced will cause detonation (eng knock)

 

1) You should flush the system and only use distilled water. Tap water has minerals in it which will cause scale and corrosion. The coolant has inhibitors in it to avoid this, but relies also on distilled water.

2) If it's hot and the fans are not clicking on then this leads me to believe you may have a faulty temp sensor. You can make a harness that temporarily hotwires the fans to test if it's simply a fan issue, or you can use a multimeter to test the sensor and signal loop.

3) When the engine gets up to temp, squeeze the radiator hoses. One should be soft, and the other slightly firm. If you have one very soft and the other firm hose then you have an obstruction.

4) Make sure you have all the air guides and cowling on the fans / radiator.

5) If you live in a warm climate area that rarely freezes you can use a 70% water / 30% coolant mix with a bottle of Redline Water Wetter. This will knock a few degrees off the top and give better cooling.

Car Overheating? Here's How to Fix It -- this is an article I wrote that may be helpful to you