2001 civic is pushing coolant into reservoir but not sucking it back in. Has new radiator.New cap,checked overflow hose. Took it to a shop . They said they did a pressure test and could find nothing wrong. took it back again and said bad head gasket. Wanted 1200 to fix. Found a mechanic said 680 plus 100 to machine head. When he checked it couldn’t find anything wrong.
Did pressure test. block test.said there were not bubbles in radiator, couldn’t get it to overheat. Put a thermostat in it and said see if that works.It still acting up. I took it for a long ride, took the cap off and saw some small bubbles coming up every once in a while.When i reved the engine the coolant pushed out of the radiator neck. I still think it’s the head gasket.Is it possible to pass a block test and still have BHG. Is there any way to confirm or just replace it and hope that’s it. Thanks
Yes, you can have a mechanic use an emission tester probe to sniff for hydrocarbons in the bubbles you see coming out of the radiator filler neck. That will comfirm you have combustion byproducts blowing past the gasket and into your coolant.
You can also “rent” a tool from Autozone’s tool loan program that draws vapor from the radiator through a light blue liquid. If the liquid, which you will have to buy a little too much of, turns yellow, then combustion gasses are present. That means you have a blown head gasket or worse. The test takes two minutes, and no talent. The coolant has to be a bit below the filler neck so none gets sucked into the tool. Be sure you remove the coolant pressure cap VERY SLOWLY using a heavy rag with the engine running to allow the pressue to escape. Do the test, and replace the cap before shutting the engine off, or you will have a reasonably good looking facsimilie of Old Faithful.