Hi,

Can ya tell me where the leak is coming from?

Location is toward middle of car so back of engine. Coolant Reservoir level comes down from Max level a bit. It is a slow leak.

1st circle has a plastic piece which was removed. Thanks in advance

 

Additional pic

 

Did you check all hoses? The heater core hoses are at the back. Pull off the engine cover and get a peek back there.

 

I can't get he photos to load, but coolant leaks that you can see usually come from the hoses where they're connected. I'm going to guess this one is from the heater hose. Check it. Black rubber hose from the back of the engine running into the firewall.

 

There is a plastic coupler that joins the heater hoses near the back of the engine (right side passenger) right at the firewall. Bet the coupler has split, and it's leaking at the joint....

 

I have dealt with multiple scenarios of coolant leaks on my G. So I have quite a bit of experience on this topic.

That looks like a leak from either the back of the engine, or the heater hose coupler like others have mentioned. If you found coolant on the floor, and it's more toward the passenger side, it's the heater hose coupler. If it's more on the driver side, it's from the back of the engine.

Here's a pic, see that hose right next to the coolant temperature sensor? That's where mine was leaking from. Good luck!

 

I highly recommend replacing the OEM plastic coupler when doing a coolant service. Mine cracked and the plastic was badly degraded on one side. Bought an aluminum coupler from O'Reilley to replaced it.

 

Are you referring to the hose where the red arrows is pointing to? Thanks for the pic

 

Yup that's where mine was leaking.

 

Cool. Thnx

Did you replace it yourself or you took to the shop?? Any advice on how to change hose?? Eg.. Drain coolant, remove certain part for easier access, etc.

Thnx again

 

I fixed it myself. I did it the lazy way, but I think it's sufficient since it's not a big leak. I simply put an additional worm clamp, right underneath the stock clamp. There's enough space for an additional clamp. No need to move the stock clamp up to generate space. That did the trick for me. No more coolant dripping on the garage floor. I check my fluid level once a week, so far so good.

 

I was able to open the cover & try to see where the leak is coming from. It appears it is leaking from a hose underneath the right(driver side) air intake thingy.

Question:

1. Do anyone know the name of the hose and/or part number? Pic 1 (1 end) Pic 3 ( other end). Pic 2 is close up of Pic 1, Pic 4 is close up of Pic 3

2. Pic 5 - I see some coolant (left over leak) in the back area. Is there another hose there or is it residual from the hose leak from Pics. I checked the back hose & there is no leak or wet spot from hose going into firewall of the car. Guess, i need to understand the diagram of how the coolant flows for the G37.

Hopefully this is the culprit because i hate to look for/change hose from the back of engine (Pic 5). Any recommendation/advice on replacing the leak hose.. eg: coolant flush, turn off bleeder somewhere to stop fluid flowing, etc. I will probably burp the system after leak hose change.

Thanks again for all input & continuous input.

 

Found the part i think but will that part number b same at dealership? Went to infiniti parts.com

 

So after researching, the hose is the bypass coolant heater hose. Do I need to bleed system if hose is replaced?

 

if you are replacing the heater bypass hose it would mean losing quite a significant amount of coolant especially coming out of the heater core. you would definetely need to bleed it if you don't want excess air in the cooling sys causing idling issues or the noise of coolant sloshing around coming from your dash as you make left and right turns.