Restem

Hi,

My civic is a 2006 ex coupe standard/manual transmission.

While I was replacing my brakes I noticed my coolant level was what seemed to be at the time, low. I had read online that for this generation civic it is common for the reservoir to appear very low or empty but that is just how it was designed. Nonetheless I added more coolant.
anyway. I resumed daily driving and car drove fine. I kept my eye on the coolant level for a few weeks and over about a month added coolant to it another 3 or 4 times. I did this because to me, the reservoir looked very low like below the min line. So then after a month I noticed a leak from my engine.

fyi I bought this civic used with an aftermarket air intake. Never had any problems with performance even after the leak began and when it started to show overheated on the dash temp gauge.
like I was saying the day I noticed the leak I found that it was coming from a hose that connected from the air intake base to the bottom right side of the engine when looking from top to bottom. The leak was was at the end of the hose part connecting to the engine. The leak was very significant and started overheating the next day.
my newb diagnosis is overfilling the cooling system with too much coolant and causing the leak. So I replaced the hose which hole size was 3/8’’ and full diameter thickness being a half inch. I added a small amount of coolant due to the fact that the leak had lost a lot of fluid. After test driving for 10 min the car still shows overheated on the dash temp gauge. The leak seems to be gone.

so my question is: what would be the next step or set of steps that need to be taken in order to resolve the overheating temp gauge issue?
from what i researched online, I figured I still need to flush the coolant fluid to get rid of any air bubbles that were introduced into the system with the leak. So I am going to flush it. But should i replace the thermostat first because that is why the temp gauge is still reading high heat? So I will flush the coolant system but would that be enough? I realize the age is old and I dont know the maintenance history of the car but figured I’d post this thread anyway to see if anyone has any insight.

Thanks,

Dan