Well, I just got in from a nice, LOOONG drive with my 2004 Disco. The temperature never climbed above normal, and I stayed warm the whole time.

Yes, this is the SAME engine with a cracked block, that was overheating if I tried to drive it and turn it off, then on repeatedly (ie, going to town and making some stops).

How did I do it?

I noticed that my problem was that my thermostat would not open when the air pocket created by the crack would get around to it.

So what did I do?

I have 3 thermostats lying around from all the testing I did, so I took one, and placed it on my work bench so that the "Y" faced up. Looking down the vertical pipe, you clearly see the thermostat. There is a horizontal metal "bar" going across the middle of the pipe, and right below that is the copper "guts" of the thermostat. If you press on the copper with a screw driver, it will go down toward the bottom of the "Y". (In other words, it opens so water can flow through).

Test it by pouring water into the top of it- none comes out the bottom.

Well, remember the horizontal piece I just mentioned? If you put a flat screw driver on that, and tap nice and hard with a hammer, you can see it start to bend. Keep tapping, and it'll make contact with the copper. Keep tapping, and it will probably split in half, with both halves bent down into the copper.

Reposition your screw driver up higher on the metal bar, and tap on both halves until the copper is jammed down as far as it'll go- that is, until the thermostat is stuck open, and cannot close.

Test it by pouring water into it from both sides- it should flow freely! Mine did.


And, after putting it back on and bleeding the coolant system, this thing is freaking SET.

Here's what happens:

Basically, your engine can't get up to temperature. The thermostat cannot function normally, and open and close to keep the temperature at a nice (I don't know, 180-210?) degrees. Now, when it idles, it MIGHT get up to 180, but as soon as you start driving and wind starts whipping, it drops back down close to the blue.

Is this a bad thing? Well, it's a lot better than having an over-heating disco! I have at worst luke-warm air blowing from the heater, and at best, nice, hot heat.


NOW- I think it's going to depend on HOW your block is cracked that either allows, or disallows this method to work. Mine is cracked in such a way that doesn't allow any coolant into the crank-case. In other words, mine is burning the coolant, but at such a slow rate, I think I could drive with this "open coolant system" for years and years.

I'm pumped about this, and though I'm still getting a new engine, I'm thrilled that I'll be able to drive it until the new block comes in.

Pat

 

Just, for the love of God, keep an eye on your oil. That crack could get worse.

 

Do you really think it could get worse? If it was caused by intense heat, I sort of feel like, given that the engine can't really warm up, it won't get any worse.

I'll keep checking the oil, but since I'm getting a new block in a couple weeks, what's the harm?

Could it hurt the heads, if I get coolant in the oil?

Could it hurt anything else that I'll have to put on the other engine?

Pat

 

Well, the first rule of thumb with Land Rovers is to have spare parts. Do you have to send your short block back as a core? If not, I would keep the crankshaft out of it. You can sell it, keep it, do what you will with it, but it's always good to have a spare.

If you have to send yours back for any sort of a core charge, then never mind.

 

No, I don't have to send my block in. That's a good idea; I'll keep the crank if it's not too much trouble.

 

Since you block is shot anyways you may want to try one of those head gasket fixes in a bottle like steel seal or blue devil. I think the blue devil has a guarantee so if it does not work you get your money back. If your block leak is small enough it may plug it up.

 

I will say that if you run a cold engine, it will stay in open loop and overfuel the whole time you are running it. This will cause carbon build up and heat your cats a little more than they are used to. If you throw a coolant leak into the equasion, you could melt your cats.

Your heads do have carbon cutters, so you should be ok for a couple of weeks, but check your oil constantly! Start getting coolant in it and you will kill your rocker shafts.

 

Great advice, OKD- I have never thought about the catalytic converters.

I won't be driving it much- just to my office 8 miles from home a few times per week for the next couple weeks, until I leave for Colorado (hiking).

By then, she'll be back in the shop for the new block.

THANKS!

 

i just did the same thing before reading your post. I believe its more likely a headgasket issue that is obviously fixed if you put a new block in it. I would be highly surprised if your block was cracked. I just put a screwdriver in mine and bent the sealing plate in the thermostat. I cant believe that more people havent done this with some success. It allows some coolant to flow thru all the time so that the air bubbles dont get locked up in the thermostat housing. Mine runs just above the blue line now and thats great for me. heat doesnt work super good like it did but at least this thing doesnt overheat now. It cant because its in open loop. Worst thing that can happen now is i have to fill the overflow every once in a while. I believe alot of people on this forum arent really car guys and listen to what others have said and get the trusty headgasket fix and then the problem persists. Im just not one of those guys. good job on fixing it or at least band aiding it without throwing money at a vehicle that is not worth a block change in a truck worth less that a block...lol cheers Kevin

 

SWEET- I'm glad I am not the only one. I noticed that if I run my heat on "MAX" with the fan set two notches from the bottom, it holds a pretty good operating temperature and gives me decent heat. If I put it on MAX with the fan cranking, it gets too cool.

Just above the blue- a LOT better than in the red, eh?! HOAH!

But, my truck is definitely worth a new block- I'll be doing it in a few weeks.