Hi Guys, I'm not too sure if you will get this new post of mine, but hopefully you will !

I would like to thank everyone that contributed to my request for help on this forum, especially JeffR1, Peter3442, and Cass3958. Your help has been invaluable and very much appreciated !! The problem that you guys correctly pointed me towards was indeed the radiator 👏

I removed it, took it to a radiator place and they informed me after testing it that this was indeed the problem. After waiting a couple weeks and loosening my wallet to a greater degree to have it re-cored, I replaced it late last week and test drove it without a problem. Yesterday I went to the Lytham Classic Car Show with BVPG (it was biblically wet !!) and it got there and back beautifully !

So thank you all so much again,
Mark

 

Thanks for the update.
It's just a simple cooling system, there's only so much that can go wrong, the rad was the last piece in the puzzle.

 

I guess I was getting to the point of considering it could have been a blockage in the block itself and that would have been really bad ! However, you were correctly adamant that it was the radiator, and that gave me confidence to get it re-cored. The engine is very strong, sounds really good and I guess it would have overheated much quicker if the blockage was in the block...so overall, a good learning curve thanks to everyone on the forum !

Thanks again Jeff
Mark

 

As Jeff said a fairly simple system that is sadly neglected at service. On a modern car which is used daily the water is pumped around and the sediment does not have time to settle and solidify. Unfortunately with our older cars that are used once a week or stored over the winter the sediment has time to settle into the bottom of the radiator and if left too long solidifies and block water ways. Every year when I do my annual service of fluids the radiator is drained and a hose run through the radiator and block. It always amazes me how dirty the water looks each year.

 

I agree Cass, the lack of use (that I am a little guilty of !) does not help these older cars now...it is something I am mindful of to the extent that if we have a nice day, even in winter, I will get one of the older cars out of the garage (my other two are Morris Minor Traveller and Rover P5B) and take it to the shop or the car accessory place for example. Like you, I do clear everything out of the cooling system at least once every two years...the problem for me with the Jag having only had it to restore for around three years is that you rarely have any idea what previous owners have done, or not done !! Although with this car I should have learned by now its the "what they've not done" that I should assume and the worst thereof !!!

Mark

 

As a belt and braces approach I would add Water Wetter which does also improve the effectiveness of the cooling system.
I added it to my V12 Jags and never experienced overheating even in traffic on very hot days.

 

Hi Martin, yes, a friend of mine swears by Water Wetter in his Rolls Royce 20/25, others have also mentioned it...think I will give it a go 👍

Mark

 

It's better not to go more than two years without changing the coolant and thoroughly flushing the system. Refill with a mix that's at least 50% antifreeze and for topping up go with the same mix or pure antifreeze. If there's a concern about silting up, a safe and economic method of removing it is citric acid solution (if I remember correctly it's 10 to 20 gm of crystals to a little of water). I said safe - the limitation on that is if there's a lot of corrosion, signs of leaks, core plugs close to tissue paper, where it might clean silt you'd like to keep a bit longer. Finally, whatever might appear in old service books and Jaguar mechanics tell you, never use Bar's Leaks (unless you're desperate, miles from home with leak that has to be closed).

If you look back at old threads, there are a few on modifications to improve cooling. The one that's most useful is the addition of a BL overflow tank. It's small, doesn't look out of place, and saves a whole lot of topping up. The tank was used on MG sports cars, wedge shaped 1800/2200, and other BL cars of the time.

 

Hi Peter, yep, I've just dropped the pure water out that I used for re-testing, and now filling the system with 50/50 antifreeze and distilled water. I have heard about citric acid solution for cleaning everything out, and I have heard that one has to be very careful with the quantities ! I have flushed the system to within an inch of its life, and with the new radiator core, I am hoping for a good few years of happy motoring finally without any silting issues !!

A friend of mine has a Mk2 with an expansion tank that was fitted before he got it, and I think it is certainly an upgrade that I am going to introduce to mine. Thank you for the heads-up on the MG expansion tank !

Mark

 

One of the areas that people forget to clean is the matrix radiator for the heating. When you flush the system out the valve for the heating should be open. On the S Type it is a vacuum switch which will not open until the engine is running but you would not do a full flush of the engine water cooling system with the engine running. It is best to disconnect the matrix and flush it independently to the rest of the system. Again you will be amazed at the colour of the water that comes out of it.

 

Interestingly Cass, I did take off both pipes to the heater matrix and rig up a connector for the hosepipe and flush through the pipes forwards and backwards...so at least I won't need to do that again for a while !

 

Cooling issues can also be internal, even boiling the engine did not remove everything.

[img alt="Crap in engine block
"]https://cimg7.ibsrv.net/gimg/www.jaguarforums.com-vbulletin/1120x2000/img_20141202_201501929_50cf81d6fd42de749988975f6d8 328e273844fe9.jpg[/img]
Crap in engine block.
Needed to remove the freeze plugs to clean the cooling channels with High pressure water.