Well, my fan stopped working the other day and so the engine overheated just a bit. The overlow tank filled with coolant, boiling colant. It spilled a lot of coolant too. So I wake up next day and I make the fan work. I drive around and BAM, the temp gauge wwent all the way to freaking hot! So I stopped and let it cool down for two hours. I added some more water/coolant solution. After that I drove around for less than a minute and the temp gauge again spiked all the way a low RPMs, but I stepped on it by accident and it decreased to normal in less that five seconds. I am confused here. I step on it and it cools, I let it sit and it overheat.

My mechanic said it could be an air pocket because I did not fill it up right. Right where the sensor is and so air heats up faster than water so that is why it varies greatly in just seconds.

Any ideas or suggestions? I am going to flush the whole thing and add the coolant correctly this time. Thanks

PS: I have a C&R radiator with spal blades and the car runs great in spite of the overheating. I killed a crx on my way to the auto shop ( I know stupid me, I could not resist it)

Get you a new thermostat and that should fix your problem. Mine was doing the same thing for a little while there so I replaced, no problem since.







I got the sonic if you got the boom.

If coolant boils in the reserve tank I think it is a pretty big deal. Yes, if the coolant is low and there're "air pockets," then it will throw off the temp reading, and sometimes cause the boiling. I would begin by doing the normal checks: thermostat (put in hot water test), t-stat cap, obvious leaks around the hoses. If all those are good, definitely do a leakdown test.

Since your fan works and you have an upgraded radiator, and if all the basic parts are good, then I'd suspect the worse and point my finger at the headgasket and/or the water pump. You can look at the water pump and see if there's any leak from it or listen if it makes any noise--it shouldn't. This is not a fact, but when I experienced this similar overheating problem, I spoke to mechanics at four different Mitsu dealers in town, and all of them said our cars have a pretty high failure rate involving the water pump or headgasket:shrug I was in denial for about three months, but it turned out to be the hg.

Hopefully it is not the HG. This is a new engine frmo VT we are talking about. The water pump is new also. Hmmm, damn it! Thanks for the pointers. I shall tell my mechanics what I found.

If it were the HG. Would a compression test be a good way to diagnose the problem? What other method can I use (my mechanics) to see if it is the HD?

Before the fan failed and it overheated, the temp gaugue would stay right in the middle with some liquid in the overflow boiling. Still, why is the overflow liquid boiling and I would still get normal temp readings on the factory gauge? Thanks for any more info

In my experience, a compression test won't tell you if the HG is bad. I'm currently experiencing the same type of issue with overheating. I did a compression test and it came back fine. Then I did a leakdown test and discovered that I'm leaking compression into the coolant passages in cylinder #4. :(

How can this be fixed? Replacing the HG? I hope that for the sake of my pocket, its not this.

In my situation, yes I need to replace the headgasket. I'd say check all the normal stuff first:

- make sure the thermostat isn't stuck closed
- remove the thermostat and run the car without it and with the cap removed, look inside to see if the coolant is flowing
- make sure the radiator cap is sealing
- fill the radiator when the car is cool and the engine is running to help get the bubbles out
- also, to get the last of the bubbles out, cover the top of the thermostat housing with your hand and squeeze the upper hose. This pushes coolant and air into the overflow, but when you let go it sucks only coolant back in.
- make sure the fans are cycling on and off

If none of this works, then you'll probably need to do the leakdown test. There's another similar thread in the General 2gNT section with more info..... http://forums.2gnt.com/dcboard.php?az=show_topic&forum=4&topic_id=56036&mesg_id=56036&page=

i thought i had a hg or whatnot problem when my car overheated after the kick ass rebuild. But it was my ecu kicking me in the ass. the ecu caused my overheating problem.
Michael
99gs HRC Stage 2000 8-Injector Setup
2004 Honda Accord V6

The ecu was causing your car to overheat? Did you have to replace your ecu? How did you solve that problem?

well the reason i replaced my ecu was because it would not turn off after xx time after you turn the car off which caused my battery to drain after xx time. After i replaced my ecu no more battery drain and no more overheating...
Michael
99gs HRC Stage 2000 8-Injector Setup
2004 Honda Accord V6