I call them frost plugs and they are usually light gauge metal "caps" that plug the sand drain holes in the casting - that is in the old days of sand cast blocks, these holes are where the sand from the hollow internal passages was supposed to flow out upon completion of the casting process. I guess casting is still pretty much like that even these days.

The descriptor "frost" results from the fact that in cold weather and with no antifreeze in the coolant, the plugs would squeeze out first when the cooling system water within froze and expanded.

I have seen holes develop in them from corrosion - but that usually takes closer to 15 years if not 20 years.

If they get knocked on, say when replacing the exhaust system or a starter etc, they can get loose.

This is a pretty good video re replacement.


The factory block heater is a threaded type so it unscrews. If for some reason you have a block heater and tje fluid is leaking from there, there might be a gasket problem or it just needs to be tightened.

The threads also means that if there is no block heater present, then there is a threaded plug instead, so no hammer required.

DISCO3.CO.UK Photo Gallery - Last additions/Block Heater and Cord for petrol V8 LR3

 

Thanks, all.

Might any kind soul be able to confirm if the photos I posted above are, in fact, the place where the "FROST PLUGS" belong?? Also, any idea of a part number? When you google it, nothing comes up for the LR3. Most of the frost plugs come up surround the D1/or D2's....

 

This is about the best I can manage. Here is a print out from Microcat of what Land Rover calls the "Engine Block and Plugs". According to the description, I believe HP3 is threaded and HP2 is more of what you would call a frost plug... a pressure fit plug. You can at least get an idea of how many and where they are from this.

Engine Block and Plugs

 

Embarked to say it was the tee at the very time of the engine. It was cracked on the underside and wasn't completely obvious since the tee was spewing collard down, into some hose that surrounds what some sort of galvanized tube and was carrying the coolant to the rear of the engine where I was looking for the leak. Found it yesterday after the sixth time. I obviously couldn't get a new bleeder valve tee yesterday but a simple ****** 1/4 internal diameter copper connection from Home Depot worked just fine to get the two hoses back together. I'll get the replacement t part next week and throw it in. What drama for a $3.00 fix. Now onto figuring out how Incan get a replacement key for my rover. Seemed to have lost one and a little worried about having only one.

 

There do not seem to be any shortcuts re getting a new key.

It seems you pretty much have to get it thru your dealer. It costs from three to five hundred dollars and takes about a month as it comes from the UK.

As such, start now while you do not need it.

The brass Tee was a good fix while you are waiting for the new tee with the bleeder screw.

 

If you replaced the bleed valve with a brass straight through connector (like I did), then be very careful bleeding the system. It took me a very long time and a lot of patience. I was monitoring the engine temp via the standard dash gauge as well as my IID tool. The system just kept sucking in more and more and more coolant and yet the temp kept getting to a point where I was uncomfortable with it. Seemed to shoot up suddenly too. Anyhow, I was careful and monitored it closely, but it just took a long time for the air to bleed out. Glad to hear you found the problem though! It usually is the simple things, so I'm glad it turned out to be the case here as well.

 

I do not know how the dealers bleed but for owners, it seems to take hours to do it properly.

The correct procedure as best I can tell is plan a day or two of filling and checking and bleeding. One does need the bleeder part of the factory tee or something like that to assist in the procedure.

The cost of hurry is too high, hence plan lots of time; it just takes patience.

I have never seen such a tangled setup of cooling system hoses in my life but then again, I lead a sheltered existence. I am more used to a Chev 350 where there is a big hose top and bottom and a couple of heater hoses - the AJV8, it is not.

http://www.disco3.co.uk/gallery/albu...ses_4_4_V8.doc