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MG TD TF 1500 - Water jacket flushing

As someone said on a different thread, one of the most common causes of overheating in our cars is blockages caused by junk in the engine water jacket. It certainly seems to be the case with mine - #1 and #2 cylinders were heavily blocked, which lead to overheating and breakdown.
The engine is being rebuilt and is in very good shape, totally clean now of course, as magnafluxing it was the first step.
But for future reference, I'm wondering if anyone has been able to do a thorough jacket cleaning job without having to remove the engine from the car?
Removing the water pump should give access to the block water jacket, and removing the thermostat and rear head plate should give full access to the head water jacket.
If anyone has done this, I would love to read a good description of the techniques used... as in future, I would think it would be a good idea to do this every few years!
Geoffrey M Baker

It's almost impossible to gain access to the engine's nooks and crannies, with enough pressure to dislodge all the crud. It just tends to distribute in different places in the engine - and the radiator. If your engine starts out clean, it will stay that way for quite a while, depending on the hardness of water you put into it. My guess is that you had plenty of years' worth of accumulation in there.

The best way I know to flush the radiator is to remove it and turn it upside down, flushing to dislodge the rust. You can look in from the radiator cap and see if tubes are blocked at the top.

Tom Lange
MGT Repair
t lange

I'd have doubts Geoffrey about a good cleaning in the car. A good cleaning in a shop involves a complete soak for a considerable period of time in a caustic solution tank followed by a thorough water rinse. You could have a go with some of the off the shelf products but I doubt you would see much improvement. One thing I might mention if you haven't run across this yet , is the clearing of the opening near the rear cylinder and the drilling of an additional hole near the front cylinder to improve the cooling.
MG LaVerne

No, I hadn't heard of that Laverne, can you tell me more?
The entire engine has been magnafluxed so I don't think any more clearing is needed, but while the engine is out, drilling an additional hole should be a piece of cake. I just need to know where and how big :)
I'll dig through the archives...
thanks!
Geoffrey M Baker

I find that this system works very well,,,

First, run the car for 100-200 miles with Arm and Hammer Super Washing Soda in the cooling system..
Then I use a back flush arrangement by putting a 2 foot length of neoprene hose on the block drain petcock, on the other end, I added adapters that convert it to a threaded connection that a garden hose can be connected to. At the rad filler cap, I put the piece from a Prestone Radiator Flush kit. To this, connect a hose to a bucket. Turn on the faucet and it back flushes the block.


Steve
Steve Wincze

Our local radiator shop has an old book listing TD flow rte and pressure test readings. Since my block is clean as new I had the radiator soaked cleaned and tested. Checked out as new. No over temp problems even in traffic in the Florida summer. Clean with fresh coolant seems to forestall problems.


Jim Haskins 1953 TD
J. M. Haskins

Geoff, Here's the web site for clearing the holes at the front and rear water jacket in the core plug area:

http://www.mg-tabc.org/library/the_hidden_water_passage.htm
Richard Cameron

Thanks, Richard. It appears this was standard on TC engines, as far as I can see.
Am I correct in saying this can be safely done to a TD as well? But that I will probably NOT find these holes in my engine at all?
Geoffrey M Baker

Geof,
I'm going to assume your machine shop will do a very thorough cleaning. Mine baked our block and degreased it, but there's still traces of gunk inside- it was horribly caked with crud! I've shot degreaser inside and will pressure wash the innards before assembly, but our's is an extreme case (I can be nit picky).

As you can see from the photo posted, the core plugs are out, for two reason (actually three):
First, obviously, is to effectively clean the water passages;
Second, is to replace those old core plugs while the block is fully accessible. This didn't start out as a "plug" for Tom Lange's plugs, but they are what's going in ours. Should the rear plug start dripping, you'll be back here on the forum asking what to do, or what you should've done!
Thirdly, since this block has been bored out to 72mm, I wanted to measure the wall thickness to see if it could handle another boring. Oh boy, only .1" thick!

Just for kicks, note the bit of wire in the lower rear cavity that originally helped secure a sand core inside the mold. There's another one in the lower front that isn't visible in this picture.

JRN JIM

Jim, I've seen the engine in the shop, and it looks brand new. To be on the safe side, I'm definitely going to go through it all carefully before installing plugs! And I'll look at the issue of drilling holes at that point...
Geoffrey M Baker

Once the block is clean, Use nothing but distilled or de-mineralized water in the coolant mix. You will still get some rust and rust scale eventually but the calcium deposits will not be there. Of course if you use the waterless coolants, you don't use water at all, but that is another story.

The water that comes out of my de-humidifier is de-mineralized enough not to cause any problems , even to top up batteries
... CR
C.R. Tyrell

The knockers were very negative when I posted previously regarding this fellas products, well this one well and truly works. What 239 removed from my reconditioned XPAG was more than impressive.

http://liquidintelligence.com.au/

G Evans

Check the cooling system thread I reactivated Geoffery
MG LaVerne

Thanks Laverne, very helpful!
Geoffrey M Baker

I also would like to flush out my block ideally under operating conditions. I removed all the welch plugs & used a high pressure Guerni to shift a ton of rusty mud from the block before I reassembled the engine. I've fitted copper welch plugs, peened & bedded with Stag. I've also had the radiator completely rebuilt & it is as new & unused. The problem is I don't want to run the car & risk pushing any remaining gunk into the radiator. Steve's washing soda method sounds good but again I don't want to involve the new radiator. The best I could come up with was to use a temporary filter made of pantyhose before the large radiator hose at the top of the block. Can anyone suggest a better alternative? Graeme I'm going to give the Liquid Intelligence guy a call today & see what he recommends. I don't plan on changing over & getting rid of the water but perhaps his cleaning agents may do the trick. Cheers
Peter TD 5801
P Hehir

If the weather is warm, run dish soap and water as coolant a few times and drain it out hot. When you're convinced it is crystal clear, rinse and fill up with antifreeze and water. DO NOT RUN WATERLESS COOLANT.
JRN JIM

I don't plan to Jim but I have to ask.. Why?
P Hehir

JIM,
I agree,,, Please explain the problem with waterless coolant.

Steve
Steve Wincze

that stuff is flammable, isn't it?
W Chang

This thread was discussed between 08/04/2015 and 10/04/2015

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