I have a '97 civic and the coolant is going somewhere but I cannot figure out where? There are no puddles and I cannot find anywhere where it might be steaming out after running it. Was thinking it might be leaking into the combustion chambers while running and being burned but if it is it is not enough to cause a misfire. Any suggestions?

 

You are either leaking or burning.

Clean out the engine bay and inspect every day or so to see if a leak is present. Is there coolant on the ground when you leave each morning?

If not, you are burning it. It will not cause misfires usually. You can see if the head gasket is leaking by conducting a compression test.

 

No puddles or leaks that I can find. Checked compression and it is decent and doesn't vary. It has a problem of starting fine when it is cold but when you try to restart warm it is difficult to start. Any thoughts on that?

 

Forget the compression test, that will only tell you if your head gasket is blown one of maybe eight ways it can actually blow. Get a radiator sniff from a smog station, have them rev you up to like 6000 RPM, if there are ANY hydrocarbons present, your head gasket is blown.

 

Small leaks in the head gasket will have no symptoms other than loss of coolant and eventual overheating. The coolant will disappear from the radiator yet the expansion tank stays full, possibly overfull (If after several trips, the plastic tank becomes empty first, followed by the radiator, it is probably a leak to outside and not the head gasket). The gasket needs to be seriously blown to have major symptoms like loss of cylinder compression, steam from the exhaust, misfiring, or mixing of coolant and oil.

A simple not always conclusive test you can do at home is to get the radiator completely full, then wait until the engine is cold. Start engine cold with the radiator cap off and rev it. Nothing really should happen in the radiator. If bubbles and/or coolant blow out, the head gasket is likely blown.

A variation of this test is to leave the cap on, and squeeze the top radiator hose. With the engine cold there should be no pressure inside (If there is, open cap to relieve pressure, then replace it). Now start engine (cold) and rev it. Pressure should not build up until the engine has warmed up significantly. If you feel pressure immediately, the head gasket is leaking.

A leakdown test (inject compressed air into a cylinder with the engine stopped) can also reveal small leaks as bubbles in the radiator. You would know it is your test air doing it because nothing else is moving. Most compression testers can be converted to leakdown testers by removing the check valve in the spark plug hole fitting. Thread into a spark plug hole, uncouple the gauge and couple to an air compressor. Set the air regulator for maximum pressure. You will need to rotate the engine until the cylinder under test has both valves closed and possibly lock the crankshaft in that position (manual car, shift to 5th gear and set the brake).