Well, the timing is looking alright. Everything seems to line up where it should be.

Hello number9, there was no record of prior replacement of the head gaskets. Looking through the receipts, it appears that all service recommendations were performed by Land Rover at their mileage intervals. The previous owner said it had never let her down until the incident on the highway. The bolts on the back bottom were really loose - loose enough for me to undo them with my fingers - which I thought was shocking. All the lower bolts were looser than they should have been.

I attached some pictures of the other bank below. It looks fairly normal, besides some coolant intrusion on cylinder 8.

BackInA88 - not sure about the cam lobe, but I agree about #7 and the hot gases.

I'm a bit stumped, I was expecting a huge blowout on #5 gasket. This engine is certainly not starting off as simple as my other Discovery. I just don't want to put this all back together without solving/fixing the problem.

 

Have you tried checking the valves? You can put the head upside down, with the valves facing up and spray some brake cleaner or wd-40 or whatever you have handy (water works too), on the valves. Let it pool up and see if it leaks through the valves into the ports.

 

That's a really good way to test the valves. Inspect the valves carefully for cracks. It is possible that the overheat caused the valves to crack. The valve seats might be an issue as well. But that WD-40 test is the best way to diagnose it.

 

I just looked over the valves. I did the WD-40 test 3 times on cylinder 5 and I didn't see anything wrong with the valves or their seats, no leaks. Water/Coolant was definitely getting in that cylinder though -- there is some rust. I am starting to think maybe the bolts were loose to the point that there just wasn't enough force holding the gasket down, or the heads are warped from overheating? Or perhaps the block is cracked -- maybe I should look into a block pressure test?

 

You can check the heads by putting a straight edge on it across a flat area and shine a flashlight behind it. If you can see light under the straight edge, that means it's warped in that area. There is a tolerance you can probably look up. I don't know what it is for Rovers. You can check it by putting a feeler gauge under the straight edge. So, say you have a .020" tolerance. As long as the thickest feeler gauge you can fit under the straight edge is .020" or thinner, it's okay.
I try to put the straight edge on it at every possible angle to check it thoroughly. For me, I feel better just sending heads out and having them machined if there's any warping at all. Most of them that I do are customer cars. So I feel better knowing it's been done.

 

I checked the left side head and it is definitely out of tolerance. Seemed to be particularly bad around 5. I am going to send both of them off to the machine shop tomorrow. I was cleaning off the head today and there was some bad pitting under some of the carbon deposits as well. I'll see what the machine shop says.

 

Interesting. Is it pitting from moisture, or does it look like something got into the cylinder and damaged the head? Bits of rings can leave lots of little marks like that.

 

There are some bits in cylinder 5 that look like this:



Then, on the head and the block it looks like the rubber burned off the head gasket and caused these marks?





Block might need to be resurfaced as well...

 

Weird. I haven't had the heads off mine in a long time. But I don't remember seeing anything like that. The marks in the first picture look like something got into the cylinder. Either through the intake, or pieces of the rings.
If you don't know the full history on the engine, I would pull the piston out of the cylinder with the head damage.

 

Agreed, would guess the maybe a ring. No metal in the pan when I took that loose. Scoring looks very odd. I'm considering just pulling the engine and rebuild/replace so I start off with a known quantity.