Have a question regarding the temperature gauge in these cars? 2003 Fit 1.5L
Would they work if there was suddenly no coolant circulating throuh the engine?
Reason I ask is recently when doing a coolant change i had lots of air in the system after the intial fill, took a while to bleed the car of all the air.
What I noticed is the coolant temperature warning light did not start blinking straight away even though there was little coolant in the radiator, so how do the Honda sensors work, would they warn you of an everheating issue if you suddenly lost all coolant or is this dummy light just for minor everheating issues and not catastrophic failures.
Just wanted to check as to how hot my engine got before the light came on.
I am worried I might have warped the head or damaged the headgasket, after i filled it intially with new coolant the car was idling for about 5 mins with radiator cap closed to the first click, with no light coming on, i then revved it to 3,000 rpm a couple of times and it started blinking as it was overheating,after whcih i turned it off and realised i had little coolant in the radiator due to trapped air, i then filled it up, idled it again for 5 mins, the light started flashing again, i then filled it up as the air was now escaping, after that i just bled the system for the third time and it seems ok now.
Also how strong are the headgskets and heads in these cars would a slight overheat damage them or am i being paranoid, i have kept an eye on the coolant and it dropped maybe 5mm from the line i marked on the reservoir and it has been 2,000km since i did the flush, would this drop be just the little air bubles escaping or a very very slow leak in the head gasket?

 

Is your oil watery/different color(outside the normal brown/black)?

If you've drove it 2k kms, and had zero issues, your probably fine. If it was damaged, you would have known 1990 km ago.

 

Cheers for the quick reply, oil is nice golden colour, i am just paranoid as i ran the engine with a lot of air in the cooling system for around 10 mins all up and wanted to know if this would damage the engine in any way. the coolant sensor did not warn me that i was low in coolant. hence i wanted to know how robust are these little engines? and would seeing a 5mm drop in coolant level after 2,0000km point to more air escaping or a small leak? in HG

 

When you checked the oil, did you notice it was thinner than normal.
Oil is usually close to the feel of maple syrup, for example.

Did your antifreeze change colors at all? It's either green or pink, if its still the same color then you're ok.

The 5mm drop, is settling, any remaining air escaping from the system.

If the cooling system sensor didn't come on indicating its overheating, youll be fine. 10 mins shouldn't done too much, especially considering you've drove for 2,000 km since.

Damaging the engine, you probably didn't do too much too it. It'll be fine, its not good to have air in the cooling system for the water pumps sake.

Overall, youll be fine, if your oil is golden, and the 5mm drop isnt nothing.

Sadly, I take my car to the shop for the fluids, I let someone else do it, and if it causes an issue, well it's that mechanic's ass, not mine.

 

See this for how I do it post #24
https://www.fitfreak.net/forums/2nd-...acement-2.html

You are correct if there is no coolant circulating the light will not work UNLESS the engine is WAY HOT and it picks up some heat from the air.

As for your engine you are probably ok if you are not having problems now after that mileage. The main way heads get warped is by adding coolant or water to the engine while it is hot and steaming the rapid change in temperature is what does it.

 

Kat and Bang are correct. If you havent had a problem yet then you likely wont.

Look at the positive side of this. You have learned how not to change coolant so next time you know what not to do. Its part of learning the trade. Fortunately it doesn't seem like that lesson will cost you.

Keep learning my friend!

Good job on getting the coolant changed yourself!

Just a note on how we do it at the shop.

There are three ways mostly.

First, open a bleeder, if equipped, fill coolant till it comes out of the bleeder, close bleeder, burp engine while running till coolant is full.

Second, attach an air evacuator to the radiator cap, pinch off overflow hose to resevoir if resevoir is opened to atmosphere, no need to pinch off if resevoir is part of a closed system, connect air hose to evacuator, watch guage until it reads negative, (now for the cool part!) watch radiator hoses collapse when the air is sucked out of the system, put end of fill hose from evacuator into clean container of coolant, flip the lever and watch it suck the coolant into the engine, run to make sure any tiny bit of air is burped.

Third, if no bleeder or evacuator available, find the highest hose on the engine that isnt blocked by a thermostat, disconnect hose, slowly fill radiator until a little bit of coolant spills out of hose or fitting it was connected to, reconnect hose, run engine and burp cooant.

Always remember to let the coolant fans come on a couple of times and recheck coolant after pressure drops and you can safely open cap. The fans coming on means you have reached operating temp if the engie is full or close to full. Beware that certain vehicles will kick the fans on when the engine gets too hot if the coolant is low. Dont be fooled and use your best judgement when filling so that doesn't happen.

The second method is my favorite. Less messy because nothing spills, fastest fill time(minutes) and no shipping a vehicle out because the flat rate tech didnt wait for the fans to come on and burp properly.

The third method may be strange and is something I figured out many years ago. Example, when i first got into the car repair business we were fixing mostly cars from the 60s to 80s. Anytime you pulled a thermostat it was on top of the intake manifold on a V8. I realized i could drain the coolant, pull off the thermostat housing, clean the gasket surface, refill it until i saw the coolant just below the gasket level, stick the thermostat in, put the housing on, connect the hose and no need to burp. Back then they didnt make that fancy funnel that fits on the radiator cap to fill without spilling. Some of the old V8s would spit coolant like a fountain or an actual steam jet if the engine was very low and the thermostat didnt open! So, as i worked on vehicles in my career i would pull off an easy to get to heater hose, coolant by pass hose, coolant hose into a carb or throttle body or any other easy to access hose, fill till it spilled and then put hose back on.

I hope these tips are something some of you can put in you bag of tricks and help you et the job one easier someday.

Good Luck!

 

Thanks for the replies. Yeah i have learned how to change a Fits coolant now. Just didn't realise they were so sensitive. My other cars filled up to the brim and had little air in them. These small engines seem to trap air much easier and can cause all sorts of issues. Will keep an eye on it but hopefully no major damage occured. We are about to get the Australian summer so cooling system will surely be tested lol.