I have an ever so small coolant leak that I cannot figure out. Facing the engine it appears to start where the exhaust bolts on the driver's side, or at least above it. The throttle body heater is deleted (previous owner), and they did a bad job re-routing it, that appears to have some old signs of a leak on the hose, but nothing underneath it. So where else could it be coming from? I'm waiting on an inline thermostat to install (international shipping is fun) so I'd love to get it sorted at the same time.

Behind the ac unit (currently putting in a new ps pump)

Under the driver side valve cover, quite a way down, coolant. Coolant ends up on the bottom of the transmission pan.

Just above the previous pick. Transmission line for reference.

No signs of leaking from the valve covers imo.

 

You seem to have an external coolant leak caused by a failed head gasket at the front of the engine. There is a small coolant passage there. I had the same thing and just did my head gaskets.

 

I have to say that looks pretty similar. I hadn't consider head gaskets as there are no other symptoms. Ugh. How was the job? I think I'm confident in doing it except for getting the heads decked, I have no idea where to even start there...

 

@WaltNYC could be right, but clean all the crap off and add some UV dye to your coolant. You will find the leak source really fast with a UV light

 

I'll have to source some uv dye. I thought that at first but I couldn't find any. I'll try harder, probably can get some shipped in. I hope.

 

@DiscoOslo Amazon, but you can try local auto radiator shops they should be able to source it for you

 

That problem might respond well to your favorite stop-leak product. Some posters don't like them, but they can be useful if used correctly. Stop-leak works best on small young leaks, photo looks like it is old. But if it works you could get a couple years driving leak free. Maybe consider loosening the cap on the reservoir and running the system unpressurized.

 

I haven't found a radiator shop here (Norway) but that doesn't mean they aren't a thing. Amazon sure, I can get maybe one kind for a GM and dex-based coolants in 2-3 weeks. It should work. I'll likely have to go that route though. I'll call my workshop and see if they have anything tomorrow.

I've loosened the cap already. Doesn't seem to be helping. Unlike the dye, I seem to see stop leak everywhere here lol. Might have to give it a try.

 

The ACDelco or Bars Leaks tablets have been used successfully in my V8s. Tends to settle into the reservoir, so needs to be stirred from time to time. I'm sure there are other satisfactory products.

 

Scrape the crud off, spray heavy duty oven cleaner on the front of the engine and let it eat. Wash with a garden hose. Will make it easier to see the leak. Another good trick is to pressurize the system without the engine running. Many times you can hear it or see it. You can use an old radiator cap and in the US the auto parts stores lend out kits to do it. BTW, it is a BMW cap.