20 replies to this topic

[OzOAP]

I’ve tried both a payen gasket and copper gasket.

What Payen gasket?
I have never had head gasket problems until TAM1521 (BK450) were in short supply. Had to use AF470 green ones, have had 3 failures of those.

Had copper in it at first, but now Ive been trying TAM1521

The gasket in your pic is an AF470, the ones I have had problems with.

[Mark506]

Crankcase ventilation is something that seems to be little understood and so easily over looked.

As the engine runs, in pulses, it will want to breath in and out. As you get some ring blow-by, this will want to pressurise the crankcase and should do so, only slightly - should.

The engine temperature also changes as it runs. When you shut it off after a run, it will tend to increase in temperature briefly, then cool off.

All these add together to cause the crankcase to breath.

Oil is hydroscopic, so it will also absorb some water (moisture) + in some conditions, you can has a small fog on the crankcase. The Blow-by and Moisture combines with the Oil and becomes slightly to considerably acidic.

Crankcase Ventilation deals with all this.

Most systems will draw in fresh air via a filter and some with a valve (to only let air in). This circulates through the crankcase and then is usually drawn off to the Manifold, often via a PCV Valve, which meters the flow and will also shut it off in a reverse flow, or as in the case with the post 71-ish Minis, a CCV System (Closed Crankcase Ventilation System). As well as circulating air through the Crankcase to remove the Moisture it also draws off fumes from the Blow-by so the engine doesn't smell. They also usually reduce the Crankcase Pressure to below that of Atmospheric, which has a tendency to reduce oil leaks.

The CCV System the Factory fitted to these cars, when looked at in very close detail is one thing I feel the factory got totally spot on. For just about any street car, except maybe in boosted applications, in my opinion, you won;t get a better set up.

I’ll happily admit I am one who doesn’t understand loads about crankcase breathing, although the above has certainly been very helpful.

I do have one question though, any ideas why the problem has suddenly got quite large? Last year it didn’t seem to be a issue running set up like it is.

[Mark506]

Might just be me but that head gasket looks like it has never been compressed or run?Steve..

Tightened down but only run the once, didn’t go through a couple of heat cycles and retorque as I thought there was still a issue somewhere

[mbolt998]

As Nick has alluded to, if your car is only used for short journeys then you will get this. The needs a good blatt, fully up to temp and on a regular basis.

 

I suffered this issue with my Clubby as it had been sitting in a bodyshop for 10 years (owned by a little old lady) moved by starting it up, moving a few feet and thats it. There was rust carnage on the rocker gear and pushrods, rust on the valve springs and caps as well. A bloody mess and all caused by the mayo build up over the years. Now when i bought the car, sorted that out and used the car on a regular basis, no more mayo or condensation.

 

I had the head off by the way, no HG damage so that was all it was. A salutary lesson learnt. Oh and i originally went Copper HG, it did not seal but then went Payen and it was fine. All on the original 998 by the way.

This is making me very glad I always used to drive long fast journeys before putting my Mini away 23y ago. It looks quite rusty inside everywhere there was coolant, but I'm hoping this is OK. But under the rocker cover it's all nice and smooth and oily. No rust at all.

[Spider]

I’ll happily admit I am one who doesn’t understand loads about crankcase breathing, although the above has certainly been very helpful.

I do have one question though, any ideas why the problem has suddenly got quite large? Last year it didn’t seem to be a issue running set up like it is.

 

 

It is possible you may have coolant getting in to the oil - somewhere - but given you've changed the gasket and the result seems the same, I doubt that's it. To me, it doesn't look like a lot of moisture that's there and it looks more like a crankcase ventilation issue.

All the same, the Crankcase Ventilation is something I would suggest needs to be sorted regardless and it would eliminate that as an issue.

It can appear worse at different times though, due to weather and even the oil itself, from one batch to the next. If left 'uncontrolled', unless you go for very long runs, it will also build up over time.
 

[Mark506]

I’ll happily admit I am one who doesn’t understand loads about crankcase breathing, although the above has certainly been very helpful.

I do have one question though, any ideas why the problem has suddenly got quite large? Last year it didn’t seem to be a issue running set up like it is.

 
It is possible you may have coolant getting in to the oil - somewhere - but given you've changed the gasket and the result seems the same, I doubt that's it. To me, it doesn't look like a lot of moisture that's there and it looks more like a crankcase ventilation issue.

All the same, the Crankcase Ventilation is something I would suggest needs to be sorted regardless and it would eliminate that as an issue.

It can appear worse at different times though, due to weather and even the oil itself, from one batch to the next. If left 'uncontrolled', unless you go for very long runs, it will also build up over time.

Thanks for the thoughts. I gave it a decent run this evening, first for a good few months, and it seemed to be running a lot happier than when I last used it/started having issues, previously it would bog down when I put my foot down, and was reluctant to start, but no such problem tonight. Still had the steam present at the oil filler cap though.

I’ll give it a oil change, sort the ventilation out, retorque the head and see what happens.