I'd really like the LS swap if that guy offering it is indeed able to offer it by end of summer or near. I think I could probably source a LM4 for cheap but that means this thing sits until that day........ which is something I'm not liking the sound of. If I did the HG and the motor proved to be otherwise ok and it lasts 25k or better after I'd be content as I could then at my leisure, do the LS swap when I'm ready to and have the time as well as the needed items all sourced.

-G

 

Hmm, How do you know the previous owner didn't just go through the same thing you did and that is why they replaced the HG. Do you know how long ago the HG's were done? I suspect you have a cracked block behind number 5. Remove the plug in 5 and look in there with a USB boroscope attached to your phone or other device. Do this when the engine is warm, Like top off the coolant, get it up to temp and shut it down without letting it overheat. Then as it cools, open 5 and look in. If you see bubbles coming into the cylinder from the seam (because the system will still be under pressure) at the top where the HG is then you either have a HG fail there which you will find when you remove the heads, or you have a cracked block. One other possibility would be that the PO didn't get the heads machined after they overheated it. A warped head could also possibly lead to this but it is more likely a crack in the block between 5 and the water passage in the V.

 

I don't, part of the joy of a used vehicle. I do have a USB bore scope and I can do this. Certainly a good call that takes little effort, I'll do it this morning. Thanks for the thought, it'll probably confirm my bad luck sadly. It will tell me if I have cylinder wall damage or not which I'm quite concerned with too so that's another good reason to scope it.

 

Why are you letting the needle go to red ???
Do you know how hot that engine is when your letting get to red ???

Your asking for major trouble actually your begging for a lot of trouble

 

I don't know, I know in some vehicles but not this one. The light comes on only after it hits red which is when the CEL begins to blink, that doesn't mean the engineer involved decided to give us a red light before damage is done but I'd like to HOPE it is the case. It was in the red under near ZERO load for about 5 seconds which is better but still not great. I needed to get the vehicle and my wife/child out of harms way, this meant getting as quickly as possible off the section of road that had a guard rail and no safe turn out when this happened. I still stopped a few times to keep it from climbing further but it did hit the center of the red twice under again, light load. Couple that with a time constraint of my work truck at les schwab having a flat repaired and them being closed Sunday meant it would GREATLY affect my work schedule Monday (tomorrow) where I have a scheduled cut-over with many parties involved and large crews of people waiting on me unable to perform their work if I didn't make it home to grab my other vehicle and get back to les Schwab in time to pickup my truck minutes before closing. Having this happen on an errand of repairing my work truck was quite unlucky. So, there's a few reasons I was pushing the absolute limit to get the vehicle back to my house.

If it's toast, it's a $750 dollar vehicle for sale or an LS swap candidate.

 

Use a $15 USB boroscope to view into your warm motor (don't overheat it just to test it) after you've turned it off and removed the relevant spark plug (e.g. #5). If you don't see bubbling, then...

It's fairly cheap to do the Inline Thermostat modification, which reduces episodes of overheating. Overheating aluminum heads tends to warp them a bit, which allows coolant to flow past the headgaskets, which likewise would cause overheating at that point even with a functioning thermostat.

And the Cometic metal headgaskets are about $200 over what the composite headgaskets will set you back.

Those 2 mods will give you reliability until the bearings eventually wear out (no way around that for any ICE motor).

You could do more, but you can also wait and do the rest later after many more miles.


For example it is fairly trivial to replace the rod bearings from underneath by dropping the oil pan, if desired. Slightly more effort to replace the main bearings, but they can also be replaced from the bottom even with the motor still in your Disco 2.

What you can't easily do is replace your cam bearings with the motor still in your Disco. I mean, it *can* technically be done but the pain level would be vastly higher than pulling the motor.

Anyway, you could get down to the cam bearings "close" to a full motor rebuild without too much effort. Probably do the new oil pump under the front cover if you decide to go as far as replacing main+rod bearings as broken oil pumps are a Disco weak point.

 

If the dash temp gauge is over the mid point it is way to hot. They are hot garbage and cannot be relied on. I won’t even guess where the red line is, but it was way way too hot.

You’ll really want this block tested to make sure it is not cracked before a head gasket job.

IMO the Britpart/Proline gasket kits are subpar. For for Fel-Pro/Mahle/Cometic or elring(what turner uses) for the head gaskets.

 

Ok, understood, damn that's a bummer on the cost of the head gasket from cometic but they've not let me down in the past. I've got a USB camera already with a mirror and light on it that'll be perfect for the job. I hope it's not a leak between the sleeve or a dropped sleeve etc. A fella I recent met is offering me two "milled and rebuilt" heads for $260, maybe that's a reasonable deal since I'd probably have to mill mine anyway. With only 94k miles on the motor I'd like to think the bearings and such have enough life left to not be worth replacing at this time. If I have to do more than just the head.... I'd probably look at a LS swap or doing a budget fix and selling it off.

 

I could look into pressure testing the block if it's something perhaps I can do at home with an air compressor. It wasn't boiling off the coolant which is a good sign but....... it HAD to have been very hot. One thing to consider is the gauge might have been reading higher than the block really was. Figure that with how quickly its eating water, it MUST have a massive leak of combustion gas into the cooling system. That said, the block itself may likely not have reached the temp that the bubbling hot coolant gasses would have which is what the sensor was reading. This is of course...... a LOT of assumption but a somewhat likely possibility. Figure that the fact that the gauge would go from middle to RED in 15 seconds can't be accurate, I mean a block takes much longer than 15 seconds to heat. Again, very wishful thinking I'm sure on my end.

 

Update: Maybe folks will catch thing's I'm missing here but this is the data I can provide today:

-Compression test, 150 across the board and 130 on cylinder #5. Furthermore that particular spark plug looks VERY clean, steam cleaned, to be precise.

-USB camera scope with 275* camera on it and looked at the piston surface, which looks very nice, I can read the markings and arrows. The cylinder walls show the factory crosshatch pattern. However I'm unable to clearly define the gasket sealing line with any kind of useful measure. Especially because there's water droplets inside that particular cylinder. There's a chance that the sleeve has cracked near the headbolts as they commonly do but I can't see that.

-I ran the engine and looked for water in the cylinder, it does make it in but I can't quite nail down where from. I don't see it pouring through the middle of the sleeve which is nice but the camera is a little difficult to use in this respect with reflections and such. It would SEEM that the water comes from the head gasket area.

Now since the temp sensor would go from normal to buried in the red in less than 30 seconds, I'm to assume that it was falsely reading combustion gas inside the coolant system rather than block temp. I had been hoping this was the case all along and I continue to hope so but the nice looking sleeves back up that theory, least so far. Is it reasonable to figure if the sleeve had a crack, I would be seeing water in the oil (which I am not on the dipstick at least) since the water would come in under the rings when the piston was in the top of the stroke and therefor I most likely do not have a cracked sleeve?

I am getting a solid trail of white smoke, the coolant system becomes highly pressurized right away and the check engine light shows misfire #5.

At this point in time, it looks worth pulling the head off for a potential HG repair job. I'm not sure what further info I can gather at this time unless anyone has ideas.

Many thanks to all who've been adding info in this thread,
-Greg