Cooling System Problem
 

Ok, so i'm driving and i notice the temperature guage is fluctuating between normal and hot often. It will go all the way up to almost the red, then it sometimes goes back to normal, then back up to the red, then back to normal etc. I noticed it needed a little bit of coolant, so I added it. Ran fine for the first part of the day then when I left work on the way home the same thing was happening. I noticed that there was some more coolant missing but I can't find any leaks. I added more coolant again today started the car and let it run for a while. Car was up to normal temp for a while, no fluctuations, as its just sitting and revving i didn't drive it, didn't see the electric fan come on, and i was revving it a little bit and noticed a miniscule amount of white smoke coming from the radiator itself. I turned the car off, the temperature was at normal operating range. What could cause the white smoke like that? and why would the guage be fluctuating? It seemed like it was a problem with the amount of fluid in the car but I can't find any leaks. Any suggestions on things to check, or how I can be certain I have enough fluid in for the coolant?

Thanks in advance!


'93 Civic, ~200k miles, manual

RE: Cooling System Problem
 

the steam (white smoke ) you see is your coolant slightly leaking - that might be why you dont see anything on the ground - its burning off -as far as your gauge going up n down , i would say the thermostat is sticking

RE: Cooling System Problem
 

Well i read somewhere that the thermostat could be fluctuating if there isn't enough fluid. After refilling it, the first trip for a 45 minute drive was fine, no fluctuation everything was normal then on the drive home about midway thru it started happening and when I checked.. the fluid was low again. So maybe there is a very small crack and its burning off slow enough that i can't see it when driving. If thats the case, how much do pressure guages usually go for that i can use to test it, and do they still sell those kits leak detection kits, with the black light and special fluid to put in? Also i noticed the fan wasn't coming on, however i have no way to check the exact temp of the coolant, perhaps it didn't get hot enough to kick on.

RE: Cooling System Problem
 

true, if there isnt enough coolant it will srew it up , but i would check the radator first , i dont know how much a pressure tester cost - but it may be cheaper to go to a local garage & have them pressuretest it
also if there isnt enough coolant in the system or if the thermostat is stuck closedthe fan wont go on either

RE: Cooling System Problem
 

Thank you.

RE: Cooling System Problem
 

Hey man the same thing happened to me last night. My fan wouldnt turn on at all. It got so hot really fast. I looked at it this morning and I had no coolant even though I filled it up last week. So I filled it up, took out the thermostat (who needs those things anyway lol) and it ran fine for the trip back home. BTW I left my car in a mcdonalds parking lot all night... So i got home and there is coolant everywhere on the engine. Turns out, the hose thing right by the intake manifold and valve cover broke and coolant was spraying everywhere. Fixed that and now it runs like a champ. Just need a new thermostat before winter lol.