Hi everyone, so my weekend's job was to flush the cooling system on my series 2, all was going well, dropped the bottom hose off and emptied the system, and yes the coolant was rusty rusty red, as expected. I've only had the car for a few months and have been chipping away at the small jobs, when I bought the car it had been sitting for almost ten years, only being started now and then over those years. So anyway I flushed the system by removing the plug on the bottom pipe and the engine plug, which was blocked and only wept coolant so I think the block is pretty muddy, ran it with the garden hose in the header tank till the water ran clear out of the bottom, I then added Preston flush and refilled, took the car for a drive for an hour or so, once home I reflushed the system and filled her back up with roughly a 50/50 mix of coolant. I then took her for a run to check for leaks and when I got back home I noticed the green coolant leaking from the back of the motor and flowing down onto where the engine meets the tranny, it looks to be coming from where the bottom of the head meets the block, I'm thinking the worst, that flushing the system and using the additive has dislodged some crud and is now leaking from the head gasket, at no stage did she overheat while I was flushing her out.
Any ideas? Probably looking at the start of a leaking head gasket?
cheers
Scotty

 

NAH, probably the heater tap, and/or the EASY, hahaha, hoses in that area.

Not impossible for a head gasket, but pretty low down on my list.

 

Could also be a freeze plug finally giving up the ghost...

Andrew.

 

The first thing I recommend is to take it to a car wash and steam clean the
entire engine and let it dry, then check for any leaks.

Cover the distributor.
Walter

 

Grant, is it unlikely/uncommon for a head gasket to leak externally?

 

Not at all. Anything is possible in an internal combustion engine, BUT, the most common is internally and usually between the cylinders.

Not aware of a freeze plug at the rear of an XK cylinder head.

 

I am with Grant. Easies first. Heater control in that location. Four clamped joints to leak.


Way back when, I learned that an ordinary screw driver failed to deliver the torque to properly tighten the clamps. Access issues. A small socket and a long extension did it right. Far more elegant, as well.


Carl

 

No, but there is a blanking plate and gasket secured by four screws as I remember. I suppose this could corrode through, but it is fairly thick metal.

 

Yes, that plate on the back of the block, and yes it is possible, but its quite thick as you said.

 

Thanks for all of your ideas guys! I'm looking forward to the weekend so I can have another look, a better look. I'll remove the heat shield from the exhaust manifold and give things a really good clean.
What are your thoughts on Bars stop leak? I see it's actually recommended in the manual to add it when refilling the system. I'm not too sure about that! Maybe it was a sign of the times back in the '70's.

 

Errrr, NO to the Bars products.

Fix the leak, drive on.

Bars Leak will clog the radiator and the heater core.

 

YUP!


At one time, I was a fan of it. Learned the hard way, it considers any small passage a leak!!!


In desperation, better products exist.


Carl

 

So Ive had a better look today, when I started it the leak was clearly visible again but after a drive and when she was fully warm it appeared to have stopped. I took a photo.

 

Looks head gasket related to me, bugga.

If its stopped (taken up) you may be lucky, but that is a rarity in the real world.

There are sealants out there claiming to stop that weeping. I have not used them, so no comment from me. Bars Leaks is a NO NO for sure.

We sell a lot of a product called Seal Up at work for head gasket coolant weeping, and the reports are it works. Copper based liquid stuff.

 

Worth re-torquing the head? if you are satisfied its coming from the head/block junction.

 

That would me my first thing to try.

 

I agree with Walter. And if after it dries and you see some staining as shown in the photo of my long discarded block, could mean a new head gasket is in order..