(D15B7 stock engine)

This car has had the idle hunting issue for several months because I took the IACV/EACV apart to replace all the O-rings and clean it, and it never worked again after that. Last year I replaced the radiator on the car.

Yesterday I drove it through town and I noticed the temperature gauge maxed out. I pulled over and popped the hood and the coolant was steaming hot in the area of the overflow reservoir. There was coolant up to the "Min" line in the overflow tank. I let the car cool off for a bit, then I added cold water to fill the overflow, then I removed the radiator cap and added some water. At first the water boiled and spurted back out the hole, but eventually I was able to add water. It took over a pint.

Next I checked the oil, and it was at the lower dot, so I added a quart.

After waiting a little longer, I started the car and it ran fine, the idle hunting did not occur, and the temp gauge stayed at about 1/3 on the dial (like normal). I drove it home on the freeway with no problem.

What are the possible causes for it to overheat, then be fine after some water and oil? Could the coolant level have been just a little low causing this (it shouldn't have been low)? Surely not the low oil.

What about the water pump, could it intermittently be failing?

Thanks for the advice!

 

Is the fan kicking on, is the thermostat working?

 

Air in the system.

 

This makes sense. What is the method for checking for air in the system, or to see if air can get into the system? I mean, other than checking the hoses for coolant leaks.

Thanks/

 

Everytime I've flushed my fluid, I always, always, start the car with the cap off to get the air out. If that doesn't work go on youtube and search up "how to burp your cooling system". Hope that helps.

Dan.

 

As for checking if air can get into the system.... I believe it's called pressure checking the coolant system. If fluid can leak out it's possible for gas (air) to get in.

 

Thanks you guys, I've started following the advice in this thread from the FAQs sticky - https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/%2A%2A%2A-basics-cooling-system-101-%2A%2A%2A-1992588/

I'm going to do the CO check with a "block tester" http://www.autozone.com/autozone/acc...ester/_/N-25dh

Hopefully it's not a head gasket, but with 320k it might be.

If that test passes I will burp the system and do a pressure check on the system with another tool rental.

I also have a thermostat I ordered once but never installed, I should probably change that out then do a flush and burp.

Thanks!

 

So I rented one of those block testers, and it didn't turn yellow. However, as I was testing eventually the coolant bubbled up into the tester. I drained some more, but eventually it went into the tester, overheated it, and warped the plastic. So this test was inconclusive.

Before this I burped the system and topped it off. Since then it has been fine while driving.

I suppose a better test for the head gasket would be the leak down test. I have a compressor, but I've never tried this.

 

You need to remove enough coolant from the radiator in order to not draw coolant up into the tester and contaminate it thus changing the color.