Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Small coolant leak from radiator - Roadster.

I've had the Roadster just over a year now. A couple of weeks ago I noticed that the coolant was on the minimum line on the expansion tank.
First I checked the oil (Eek! ), fearing the worst, but it's OK.
So I added some (recommended) antifreeze to bring the coolant to the half way point, and marked the level on the expansion tank with some translucent lens repair tape......

Red for the minimum level, and orange for half way between min and max.

I've never suffered hot running, and the temp is rarely over 90degreesC. When I first 'checked it over' - a year ago, there was a small drip (not me I might add) on the 'heat exchanger' above the oil filter. I tightened the hoses and that was fixed.
Over the recent Curborough weekend I did 280 miles, and once cool, the level had dropped about 1mm. It would not have been noticeable had I not marked it. So I went underneath with a torch, and found what is best described as a tiny 'damp patch' on the bottom offside corner of the radiator. It's so small that there is no drip onto the floor, and is on the side reinforcement bracket. So there must be a 'pinhole' somewhere. You can just make out a tiny drop of water in the next picture..........it's right on the corner of the bracket.


The obvious solution to this is to drop the radiator and have it repaired. Or better still get a Mulfab alloy replacement.....if I could squeeze that one past MrsW.
But that's a lot of work when it's been Ok for a year.................
I wondered whether to leave it for now and keep an eye on the level OR put some Bars Leaks in the system. I appreciate that there are differing views on cooling system sealants, but I've used Bars over the years without problem. Anyway I posed this question on Mogtalk, and the consensus was to try K-Seal. http://www.kalimex.co.uk/section.html?

It arrived this morning so I got to work..........first I drained some coolant from the radiator using the drain tap into an ice cream container. This is with everything cold.


Next I removed the radiator cap. This needs a good grip as it doesn't have the usual wings and is stiff to loosen.


Here's the product with the information sheet, and a reminder what the recommended Ford antifreeze looks like.


And here it goes, looking like Tapioca pudding (or worse)......
The colour is a good match for the bonnet tape!


All that remained was to top up the coolant, and run the engine to full temperature. It took a long time before the thermostat opened and the bottom hose got hot. The tiny damp patch has gone (for now), so we'll see how things progress.

Dave,
sad to see it failed so soon & I am glad you didn't have to revert to the old trick of adding an egg to block the hole.
Good luck
John

Dave

As my car was roughly made the same afternoon as yours, I fear similar things might happen to me. I have therefore sent my kids out to inspect the radiator. Further to this my heater knob has been checked and the nurled nut is secure. Please report any additional defects asap so that I may secure said items before they fall off.

Dave,
Two points:
(i) I know you always play down your camera but as always the close ups are great- many thanks

(ii) As to the leak itself. This is a bit of a 'flyer' but I'd be interested to hear what you think of this approach: Unlike 'traditional' anti freeze mixtures which are, of course basically ethylene glycol mixes, most manufacturers now recommend OAT ( Organic Acid Technology) coolants. They can do this when systems are heavily based on alloy components because these mixtures work by 'etching' the system and alloy components can take this without a problem
When we come to a trad, there is much more brasswork in the cooling system and brass is much less tolerant to OAT- not least because the OAT-based coolant eats away at the brazing.

Thus, if we use a Ford recommended coolant- fine for the original Ford, alloy system, then we aren't doing ourselves any favours

All thoughts gratefully accepted!

Regards

So that's where you've been hiding. Missed your comments and topics.

On the subject of 'leaks'. Our 2007 4+4 has a re occuring drip into the passenger well which seems to be related to two push on clear plastic drain hoses that shift or fall off of their elbow joints positioned just over the gear change cover, behind the radio. Then they leak yellow oily fluid. (yes, Dave, I need to put a jubilee clip on them). Has anyone else had this problem?

'Morning All.

My camera does close up well, but it really is rubbish beyond about twenty feet!!!!

The Ford antifreeze is a (Morgan) factory recommendation GLLH, so I would hope that they have their eye on the ball.....
Interestingly the coolant which came out was 'crystal clear' - just with a hint of purple. I suspect it will now be more Tapioca like.

Anyway.......

Frank - I haven't been hiding on Mogtalk, juat had nothing much to contribute, and have been in Cornwall last week. But I have three new posts on the way this week, all being well, one of which is my definitive guide to Neoprene. So you can look forward to that...... I can't think what your yellow oily fluid is, but antifreeze is oily. Sure it's not a heater leak??? May be time for some K-Seal.............

By the way - during this exercise, I had occasion to be under the bonnet while revving the engine using the throttle cable. I was surprised to see that the coolant flows through the 'header tank' with lots of turbulence, so it's more than just a header tank in the old fashioned sense. It was also apparent that despite the temp gauge rising to 90degrees, it was only then that the thermostat opened and the bottom hose got hot.

Dave,
For the very reason you mention I started with the red/pink but my normal favourite brand is Comma ( historical reasons and very convoluted) and I noticed that, certainly so far as the 4/4 is concerned, their factory charts recommend green (' Extreme Green' in their range)

Being a typical nit-picking lawyer, I rung them up and managed to have a long talk with one of their chemists and what he told me was basically the issue I raised in my post.

However, in the interests of fairness ( and because Mike Duncan is taller than me!) we're trying red at the moment. No ill effects so far

Regards

Am I alone in finding the colour and consistency of that "sealant" very worrying...?

What does it look like in the expansion tank? Does it disappear?

Can it still be checked for "freezing point" in the usual way at a service, or does the presence of the sealant interfere? I presume it's still done on specific gravity.

Nigel

Here's a Boxing day update:
The coolant is still crystal clear.
There is still a wet patch on the corner of the radiator, which seems slightly worse in the freezing weather, but no wet patches on the carpet.
The coolant level continues to fall slowly. I've topped it up again today to my orange arrow, but have this nagging feeling about 'the problem'. Having said that there is no mayo on the oil cap, it's crystal clear, as is the dipstick.
Obviously cold weather will reduce the volume of the coolant, so I would expect to see a slight fall, but it's more than I would expect.
I can't help but wonder about the head gaskets, but then I am a bit of a pessimist. I'll keep you posted.

Not a problem I've heard of with the V6 Dave (compared to the likes of Rover's K-series ) but then I've not really been following the history of the engine.
Hope you find the real problem soon.
Cheers,