Are these usually slow leaks that is safe to continue driving assuming I watch the coolant level? Thanks.

Like any leak, slow at first then it will get worse... the low fluid level should save you if you stop as soon as it comes on... and keep a beady eye on the temp gauge, as soon as it moves off centre, stop.... Pete
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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

You could put a bit of Barrs seal or Radweld in the coolant, it's not a permanent fix and wont seal gaping holes, but by the looks of it yours is only weeping. So it should buy you some time while you assemble the parts/tools or shop around for quotes to get it fixed properly.

I would not go down the Barrs or Rad weld route
These modern radiators have VERY fine water gallerys in them and get blocked very Easley they also run at higher temps and pressure
Keep an eye on your water level and fix it properley as soon as you can

So long as the radiator sealant is a "non-clogging" variety (check the bottle) it shouldn't be a problem. The formulation of these things has moved on in the same way radiator design has.

Problems only really come with it through misuse. ie. keep adding more of the stuff to try and fix a leak when it didn't work the first time around. It got a bad reputation in the same way body filler has, it's fine when used correctly but causes nothing but problems when used for bodging.

Having ripped apart my old gearbox oil cooler I wouldn't go anywhere near the stuff, not worth the risk.... just fix the leak a.s.a.p.....  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Thanks folks, I think I'll just take a gallon of coolant with me on my trip and check it often. Its probably been there a while without me noticing it. Its been about 2k miles since I bought it. At that time the coolant level was at about 1/2 way between Max and minimum. Now its close to minimum. Just ordered solenoid check valves so might as well do it all at once.

About 15k miles ago PO replaced the chains, guides, water pump, t-stat, hoses. Valley pan was resealed and not replaced. He didn't replace things at the rear of the engine. I will check later to see which gaskets are new. I will get the YouTube link up today and you can judge the rear hose conditions. They all looked in great shape as if they were changed not long ago.

I've seen the valley pan kits but what do I really need/should replace and what is reusable?

You really should find out where the water is coming from before stripping it all out... water leaks can be in one place and the water run a fare way before you see it...

Worth an hour getting the covers off from under the engine, drying up any coolant you find and using a pressure tester to find the leak...

A mate of mine had his engine in bit's before he realised that blue screenwash, the same colour as coolant, was leaking out the washer bottle  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Even a UV dye kit isn't expensive these days. I bought a kit that does AC, water and Oil for about £40 a few weeks ago, you can get cheaper ones, but mine was a pro-grade one.

You might well find you have more than one leak, you've just noticed the worst one. So giving it a going over with a UV kit or pressure test kit (or both). Might save you having to strip it all down again to get access to another one you didn't realise you had before. On the face of it though it does look like the valley pan gasket. I think i'd also be inclined to do the cam cover gaskets while you have it in bits, as they'll be easy with everything else out of the way. If you buy a complete top end gasket set, you'll have all the gaskets you might need.

Thanks guys I posted the YouTube link in my other thread. Valve cover gaskets were also done when PO did the timing chains 15k miles ago. But on the video you will see some oil leak. I recently did the O rings on the oil lines at the filter assembly. Not sure if the oil seen is residual from that or something else. After out trip I'll get in there with a smaller video recorder and see what else it shows. Maybe its time to I vest in a video bore scope.

I'm not looking to skimp on needed parts but I don't like wasting perfectly good ones either.

Reviving this old thread. Wow 2 years with the urban tank. So I still haven't done the valley pan gasket. The leak is minimal but will get to it soon enough. I also have/had a pin hole leak in the radiator but a new one coming. I was wondering how many miles a valley pan gasket should be good for?
After contacting Permatex regarding best sealant to use for a reseal they said Ultra Gray would work best . I think that is what the PO used 30k miles ago. No knowing if he prepared the surface correctly or torqued correctly.
I have a hard time believing BMW has made a proprietary sealant that is better than those that specialize in sealants.

When I did my timing chain and guides I also replaced my valley pan and PCV valve. There is no sealant recommended, I bought a new febi bilstein valley pan with the sealant already applied. I could see where mine had been weeping but you just need to thoroughly clean off the old gasket face with plenty of rag blocking the inlet ports and then torque up the new one in place following the procedure in Rave and you will be all good
Mine was £30 so not even worth trying to reseal the old one and touch wood mine doesn't use a whiff of coolant

Of course they don't recommend a sealant instead of buying a $50-60 part. In the RAVE manual it still says replace the gasket like on the M60. It's the principle. Now if BMW/Land Rover has a TSB stating the valley pan warps or the sealant is proprietary then I might consider replacing the pan. I may consider doing both the M60 gasket with Ultra gray. Still trying to understand why the pan isn't permanently bonded to the block.

Your call really, i had a search around and found a few people that had suffered with leaks so i just opted for the febi bilstein item as quite reasonable here and i didn't have time to mess about and certainly didn't want to take it off again.
You can see mine had gone a bit crusty.
The part number is LCW000010

http://www.ebay.co.uk/itm/NEW-FEBI-BILSTEI...SwiwVWTxuN

Great pics. Thanks. They show that the gasket didn't actually fail as in tear but failed to hold adhesion to pan and or block.