Lancia Motor Club

Model Technical and Interest => Aurelia => Topic started by: Charles T on 15 May, 2020, 07:00:13 PM

Title: B20 - water leak issue
Post by: Charles T on 15 May, 2020, 07:00:13 PM
I hope that the collective knowledge and experience of the Forum may be able to give me some pointers with a water leak issue. For some time now, I have noticed a small collection of coolant water along the top of one of the gaskets on the left hand side of the engine of my B20.

I have tried (but may have failed!) to attached two photos:
1.   General location
2.   Specific area enlarged

My assumption is that this is coolant, due to the slight green colour.  It shows as a damp / wet area along the line of the top of the gasket between the cylinder head and the rocker cover.

I can make the following observations:

1.   The volume is small, and tends to evaporate off almost as fast as it appears
2.   The water level in the radiator has not dropped by any noticeable amount
3.   There is no obvious sign of oil in the water or indeed water in the oil
4.   I have not had any issues with high engine temperatures

Item three could well be a result of low mileage usage recently.  I had almost resolved the previous problem with the fuel tank and lines but not quite before mid March, hence no miles done recently. Item four could be also be due to the lack of mileage, together with actively trying to avoid heavy traffic and high temperatures.

My knowledge of engines and mechanics is limited and so I am feeling my way slightly with this one.  The obvious explanation would be water leakage from between the seal and the rocker cover. I am reasonably sure, however, that the rocker cover should not have water in it!

I did explore to possibility of water coming from above somewhere. The most obvious source would be a slight leak from the tap which controls the flow of water to the cabin heater but I believe that this is too far away. It also seems unlikely to be anything to do with the windscreen washer, again wrong location.

Before I think about taking off the rocker cover to have a look, does anyone have any suggestions?  I am unable to do anything at the moment, as the vehicle is stored in a separate location to my home. It would be useful to have some possible causes and solutions in mind.

Thank you for any input,

Title: Re: B20 - water leak issue
Post by: fay66 on 15 May, 2020, 11:50:39 PM
Can't help on the leak itself but the green is is typical of antifreeze coolant seepage.
8227  8)

Title: Re: B20 - water leak issue
Post by: GG on 16 May, 2020, 12:50:10 AM
Reconsider the heater hose and tap: it could be blown back by the fan. Also, sometimes the alum Y that goes into the radiator gets corroded and there is a wee leak at the radiator connection. Doesn't seem like head gasket up that high.

Title: Re: B20 - water leak issue
Post by: Sebastien on 16 May, 2020, 08:27:57 AM
What I think you have is a leak on the contact face of the inlet header into the cylinder head.
The appended set of pictures will show you the aluminum header, and the inlet side of the cylinder head. Between header and cylinder head there is a long and thin gasket. The header is fixed by a multitude of small nuts. As you cannot access the bottom nuts the only way to take off the inlet header and exchange the gasket is to take off the cylinder head!
In your case this is even more involved as you have a Nardi set up with twin carbs, so the header is also special - but it is the same gasket!
If the leak is not too important I would recommend driving the car more often, and check frequently on the water leak.

Title: Re: B20 - water leak issue
Post by: chriswgawne on 16 May, 2020, 09:07:27 AM
Perhaps corrosion in the inlet manifold casting? Or maybe the bridging manifold under the carbs isn't sealing on the inlet manifold surfaces -Are they level with each other?
You need to take it apart and have a proper look. You can just remove the offending head which is a straightforward job. In my experience leaks only ever get worse.
I wouldn't recommend any leak sealing additives to the water as these can end up settling in the bottom of the radiator.

Title: Re: B20 - water leak issue
Post by: Niels Jonassen on 16 May, 2020, 09:51:37 AM
On which side does the water collect? The inside or the outside. If it is on the outside a leak at the intake manifold is unlikely

Title: Re: B20 - water leak issue
Post by: Sebastien on 16 May, 2020, 10:19:08 AM
Niels, I found the pictures by the OP quite clear, they showed a spot at the top of the inlet manifold.

Title: Re: B20 - water leak issue
Post by: lancialulu on 16 May, 2020, 10:41:53 AM
Is the correct antifreeze installed?? Green would lend itself to be wrong if UK as it should be glycol based and blue, but in Europe more generally green can be glycol based although it is worth checking as I would have expected a blue telltale. If not glycol this is a problem for older alloy engines and should IMHO be changed.

Also have you tried to nip up the top row of manifold nuts. Chris Gawne makes a good point about the two inlet manifolds need to be level otherwise the carburettors will exert a pull on one or other manifold when the carburettors are bolts down. I would has another poster suggests take the carburettors off and take it from there. Taking a head off is a bit drastic at this time but might be necessary to repair coorrsion to the inlet manifold. I note that Cavallito has re-manufactured manifolds for B20.

Title: Re: B20 - water leak issue
Post by: JohnMillham on 16 May, 2020, 02:23:07 PM
Hello Charles, Could it be some sort of green gasket goo oozing out under the rocker covers? If you are not losing water, you have little to worry about and I certainly wouldn't be thinking of removing cylinder heads unless you have a very good reason.
I suggest you use the car a bit more, as soon as you can, before making a hasty decision. Regards, John

Title: Re: B20 - water leak issue
Post by: Charles T on 16 May, 2020, 05:57:13 PM
Thank you all very much for these suggestions.

At least the consensus seems to be that it is probably not the cylinder head gasket. 

I will take a more detailed look at the inlet manifold, plus the heater hose and tap, with a view to doing some exploration.

Sebastien thank you in particular for the photos.  This will help to put it into perspective.

Not sure about whether the correct antifreeze is present but the coolant is due for a change anyway. I did check the manifold nuts and a couple where not quite as firm as I might have expected but this does not seem to have solved the issue. 

It seems logical that the inlet manifolds would need to be level and I had not considered this.  I guess that there would be a lever action of one against the other.

Hi John - I am not sure about gasket goo.  It seems more water based, leaving a slight green residue behind, a bit like the staining you see sometimes around leaks on couplings on copper pipes on a domestic central heating system.

I was hoping to get some more miles on this spring but, for obvious reasons, this has not been possible. Unfortunately for me, the car is not currently stored at my home! I will report back when I have some more news.  Thank you again,


Title: Re: B20 - water leak issue
Post by: brian on 17 May, 2020, 08:32:27 AM
On my B10 I had a pin-hole due to corrosion of the the top hose mount on the engine and so I had almost no obvious signs when I had driven (heat evaporated water) and it only showed when I did very few miles. I did break sigh of relief as easily sorted.

Title: Re: B20 - water leak issue
Post by: Brian Long on 17 May, 2020, 10:18:00 AM
Just a passing comment, but I see so many photos of Aurelia brake resevoirs with their plungers 'down'. I understand that they should remain 'up' thereby maintaining a slight positive pressure on the brake cylinder cups to maintain seal. My B12 plunger stays 'up' month in, month out.

Title: Re: B20 - water leak issue
Post by: Charles T on 14 June, 2020, 04:48:21 PM

Well I was able to take a further look yesterday, and it is definitely the intake manifold.

I will check again that the top row of manifold nuts are tight and then see if it still leaks.
I have changed the coolant, and the antifreeze that came out was green but did not appear to be particularly dirty.
Blue, glycol based, antifreeze has gone back in.

Thank you all for the suggestions.
I will report back with any further development.


Title: Re: B20 - water leak issue
Post by: chriswgawne on 14 June, 2020, 09:18:09 PM
Inlet manifolds can suffer from internal corrosion as I said earlier. Best to have  a close look asap I would suggest.

Title: Re: B20 - water leak issue
Post by: DavidLaver on 15 June, 2020, 01:54:24 PM

Am remembering the need to cut cornflake box gaskets to level up between left and right heads.