Ok so as of the last week I've been finding coolant stains on my driveway. So I decided to do some digging and thought it was my upper rad hose so I changed that. Then did a full coolant exchange and now it's leaking again but I think I know from where. I just want someone to confirm my logic.

So here's what I know and what I've did

The hose that routes to the ground from the reservoir is draining excess coolant from what I'm guessing. I may have put too much coolant in when I refilled the car.

Reservoir is bubbling as well (Temps have been 98+ the last week)

Changed rad cap with one from advance auto

So any ideas? Oil looks fine and I drove this car 5he week before on a 3 hr road trip and all was well.

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Mod note: Title corrected to more accurately reflect thread content.

 

Being in Texas we have hot days like that almost everyday in summer. As long as I keep the coolant between the high/low marks no leaks. If I keep it at the high mark.. I get some overflow for what it's worth.

 

The overflow hose will leak out fluid if too much in system

 

Could be from passenger side by battery box. there is a plastic coupler that is prone to failing.

 

Ok I've been doing more digging and thinking, checked radiator after roll call and radiator looks bone dry, overflow is empty as well. I'm leaning towards a bad rad cap that isn't holding pressure as well. I just recently bought one from advanced auto and I'm assuming it could have been bad? Oem would be best in this case. Any other input is appreciated.

The coupler towards the passenger rear looks fine and I haven't noticed a leak under the car in that area. Only in the front right under the overflow

 

Dried rad fluid will cake up either at cap or hose

 

So from what I've gathered and read I'm either looking at a head gasket issues (which is weird but still a possibility) or a leak somewhere I'm not seeing. I will be doing a head gasket check tommorow to get that out of the way.

I'm hoping it isn't because I got the car less than 5 months ago and it was in pristine condition so I would hate to incur such a huge repair bill after owning the car for such a short amount of time.

I could swap the engine myself with a lower mileage one (I swapped engines in my last g35 in my driveway) but that's the last thing on my mind because of the sweltering heat these last few weeks.

I'll keep the post updated as I run tests.

 

New rad cap fixed the issue.