Main IndexAuto Repair Home Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN









Search Auto Parts

Engine temp light coming on when idle


  Email This Post



sharkb0y24
New User

Aug 4, 2016, 10:00 AM

Post #1 of 4 (828 views)
Engine temp light coming on when idle Sign In

Hey guys. my wife has a 2014 chevy sonic, around 90k miles on it. The other day the engine temp light came on. I checked the coolant and it was full. Took the cap off, steam poured out. Once the cap was off i started the car and the coolant just gushed into the hose into the radiator. I was thinking the thermostat was going out, but not 100 percent. Any ideas?


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Aug 4, 2016, 11:34 AM

Post #2 of 4 (815 views)
Re: Engine temp light coming on when idle Sign In

Coolant was full where? At recovery tank with a pressure cap or radiator (most don't anymore) with a pressure cap? Full at the separate tank if it got hot isn't surprising but doesn't mean radiator is full.


Do fan(s) come on or where they if you know?


If so and overheated this new at idle with fans on the probable reason is gasses (vapor) in the cooling system from the too famous head gasket failure. If known full and fan(s) working you would feel from cold the thermostat open and highest radiator hose should wait a bit to warm up at all. If it stayed cold and still showed too hot a thermostat would be high on the list but no assurance when overheated that damage didn't happen.


In short, I'd be checking for a blown head gasket,


T



sharkb0y24
New User

Aug 4, 2016, 11:56 AM

Post #3 of 4 (810 views)
Re: Engine temp light coming on when idle Sign In

There is only one coolant tank under the hood. It was full before i took the cap off, after starting the car the fluid drained into the radiator. The fans come on, hoses are hot. I check the oil this morning and it looks fine, car drove fine.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Aug 4, 2016, 1:52 PM

Post #4 of 4 (805 views)
Re: Engine temp light coming on when idle Sign In

On many of that type with only a pressure cap on a pressure recovery tank the heated liquid coolant goes there but any gasses could and are near certain inside the engine/radiator. Vapor doesn't cool, liquids can and do.


So it blows it out, looks full and isn't. When you started it up and fans if on quickly suck back coolant to radiator if all is tight/sealed, no vapor or air. Many vehicles of that type you really need to fill coolant by vacuum machine or vapor stays trapped in engine side.


But if all normal there wouldn't be any vapor inside. Head gaskets frequently add combustion gasses, possibly not all the time and the vapor doesn't cool engine and it overheats making whatever reason worse.


It's early and hard to know right now. The so called "head gasket" doesn't have to contaminate oil, leak anywhere seen just get high pressure combustion gasses in that doesn't purge out.


It's on the high suspect list IMO. Diagnosing that out to be sure of it is not one easy thing or test. You do want to know if yes or not as best you can because if taken apart you lose chances to know almost certainly that's the problem. Then if it had been hot enough if only a head gasket job will fix it or damage is worse you really don't know till apart.


Alloys used for engines can't take heat like heavy cast iron so this bull (expensive bull!) is somewhat common. It only takes one good overheat or bad luck and it happens. Kinda new for this - check if any chance of warranty or recall of the issue this new.


I'm not sure and can't be from here. IF need be send it out for diagnosis but don't overheat again to do so,


T







  Email This Post
 
 


Feed Button




Search for (options) Privacy Sitemap