Help on how to diagnose coolant leak: Intake, valley gasket, or head gasket?

[Surf]

2002 Disco. Is there anyway to tell? As I take stuff apart, will it be obvious on the gasket surfaces what was leaking?

I use the truck as a DD, and downtime needs to be minimized. I also don't have a ton of money, and if the head gaskets aren't leaking, I'd like to stop with the intake and valley gasket if it is all it needs.

It has been leaking from the back of the engine for at least a year. I used to just occasionally add coolant, but for the last few months, I've been having to add coolant every 5-6 days. It has overheated a couple time... well, not overheated, but I noticed the needle was climbing and the light was on. As soon as I would pull over to add coolant, the light would be off, and the needle would be in it's normal position. Luckily, after immediately pulling over a couple of times, it wasn't boiling over or trying to spew out coolant. I would just carefully remove the expansion cap lid and add a little to make sure it didn't overheat until I could get back home and let it fully cool to add the right amount.

There is no cross contamination of oil/coolant. I've been really putting this off, and I think it's finally time to dive into it. Thanks for the help.

 

[gmookher]

You need to know where its leaking from, any idea?

 

[squirt]

You say it's been leaking from the back of the engine... Have you seen spots on the ground? Is the rear of the engine coated with gunk, or is there other evidence that you can trace to find the source of the leak? Try cleaning it off and see where the fresh coolant shows up.

 

[pdogg]

I started into it this spring and got the entire gasket kit for the upper and lower intake manifold.. I stopped when I removed the heater core pipe at the intake, a $0.95 rubber O-ring was nearly 1/2 gone.... buttoned it all back up with new O-ring and no more leaks.. it's likely you have a lower intake gasket leak.. quite common...

I imagine someday I'll be going in again, as I only have 50k miles on mine..

 

[Blue]

http://www.discoweb.org/forums/showthread.php?t=60016

 

[slug slaughter]

I'm currently digging into my 02 for the second time; I did this very same thing back in Nov. 06, bought the valley pan gasket set from Atlantic British (both times). It is leaking at the driver's side rear upper intake, valve cover/headgasket area. kind of where it all meets at that little nearly impossible corner to see w/ the naked eye, at that particular point on the engine, you're guessing at where it is exactly. The first change out for me was factory fault, in that they where the last to touch it, the second fix was on me so now its a wash, and i'm back at zero sorta speak. I as well have no cross contamination of oil/coolant, IE: no bubbles in the oil or milk chocolate looking oil.

My question:
Now that I have dug into this for a second time, I'm questioning the route of the coolant, how can coolant be coming out of the valley pan area or those silly little valley pan rubber gaskets being held down by those silly little valley end cap brackets. :banghead: